Fish oil: lower triglycerides, no fewer deaths

Fish oil is one of the most tested supplements there is, and the big answer is flat. A Cochrane meta-analysis of 45 trials with 143,693 people found that more EPA and DHA, mostly from capsules, made little or no difference to deaths from any cause (RR 0.97, 95% CI 0.93 to 1.01), with high-certainty evidence. The same review found a possible small cut in coronary heart disease events across 32 trials, RR 0.91 (0.85 to 0.97), on low-certainty evidence. That means 167 people taking it for one to benefit. In VITAL, 25,871 US adults followed for a median 5.3 years, major cardiovascular events did not fall significantly (HR 0.92, 0.80 to 1.06). What fish oil does measurably is lower triglycerides. Across 16 small trials with 491 people it cut them by 25.5 mg/dL against corn oil and raised HDL by 2.5 mg/dL, with no change in LDL. EFSA found too little data to set an upper limit, and both EFSA and the FDA treat supplements of up to 5 g of EPA and DHA a day combined as safe for adults. More is not free of risk below that line: atrial fibrillation rose in trials above 1 g a day. Cod liver oil also carries preformed vitamin A. By the USDA figure a tablespoon holds about 4,080 mcg, above the 3,000 mcg a day that pregnant or breastfeeding women are advised not to exceed from supplements.

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The numbers, per 3.5 oz (100 g)

USDA entry	kcal	Fat
Fish oil, cod liver	902	100 g
Fish oil, herring	902	100 g
Fish oil, menhaden	902	100 g
Fish oil, menhaden, fully hydrogenated	902	100 g
Fish oil, salmon	902	100 g
Fish oil, sardine	902	100 g

These are the USDA entries that are fish oil, not foods made from it; they differ in cut, part, pack or preparation. Linked names have a page with the full profile and per-portion figures.

How much is actually in it

NIH notes that cod liver oil supplements provide vitamin A and vitamin D in addition to long-chain omega-3 fats. — cod liver oil supplements Evidence E source
Cod liver oil supplements provide vitamin A and vitamin D as well as long-chain omega-3s

What a real portion looks like

USDA lists cod liver oil at 30,000 mcg of vitamin A, all as retinol, per 3.5 oz (100 g). A 4.5 g teaspoon then carries about 1,350 mcg of preformed vitamin A and a 13.6 g tablespoon about 4,080 mcg, above the 3,000 mcg pregnancy ceiling on its own. — USDA SR Legacy Fish oil, cod liver, FDC 173577 (n = 1 food) Evidence E source
Per 100 g: vitamin A 30000 mcg RAE (all retinol), vitamin D 250 mcg; teaspoon 4.5 g = about 1350 mcg RAE; tablespoon 13.6 g = about 4080 mcg RAE

What your body absorbs

A network meta-analysis of 64 trials found krill oil and fish oil change blood lipids equally, with each gram of omega-3 lowering triglycerides by about 9 mg/dL. — 64 RCTs of krill oil or fish oil (n = 64 trials) Evidence A source
Krill vs fish oil TG WMD -4.07 mg/dL (-15.22 to 7.08); per 1 g n-3: fish oil -8.97 mg/dL, krill oil -9.84 mg/dL
In a 128-day trial in 60 young adults, a fish oil with more than 95% re-esterified triglycerides raised red cell EPA and DHA more by week 16 than one with under 70%. — 60 young healthy adults, about 2,500 to 2,750 mg EPA+DHA a day, 128 days (n = 60) Evidence B source
Higher erythrocyte EPA, DPA, DHA at week 16 (P < 0.05), size not given in abstract
In a placebo-controlled trial in 74 adults over 14 weeks, DHA and EPA from algal oil reached the blood as well as from fish oil. — 74 adult men and women, 6 and 14 weeks (n = 74) Evidence B source
Plasma phospholipid DHA and EPA non-inferior for algal vs fish oil

What cooking and storage change

Laboratory data suggest the omega-3 fats in fish oil oxidize easily, which is why food makers encapsulate it, most often by spray drying. — 39 laboratory encapsulation studies (n = 39 studies) Evidence D source
Spray drying 42.86%, freeze drying 21.43%, electrohydrodynamic 19.04%

What it does to your health

A 2022 dose-response meta-analysis of 71 randomized trials in 4,973 adults found EPA plus DHA at 2 to 3 g a day lowered systolic blood pressure by about 2.6 mm Hg and diastolic by 1.6 to 1.8 mm Hg. — adults 18 and over in 71 randomized controlled trials of DHA, EPA or both, median combined dose 2.8 g/day (n = 4973) Evidence A source
2 g/day SBP -2.61 mm Hg (95% CI -3.57 to -1.65), DBP -1.64 (-2.29 to -0.99); 3 g/day SBP -2.61 (-3.52 to -1.69), DBP -1.80 (-2.38 to -1.23)
A 2014 meta-analysis of 70 randomized trials found EPA plus DHA lowered systolic blood pressure by 1.52 mm Hg and diastolic by 0.99 mm Hg compared with placebo. — 70 randomized controlled trials of EPA+DHA from supplements or food, mean dose 3.8 g/day, mean 69 days (n = 70 trials) Evidence A source
SBP -1.52 mm Hg (95% CI -2.25 to -0.79); DBP -0.99 mm Hg (-1.54 to -0.44)
In a 6-month double-blind trial in 161 healthy adults with normal blood pressure, eating omega-3 enriched chicken and eggs lowered diastolic pressure by 3.1 mm Hg. — 161 healthy normotensive adults, at least three portions a week of omega-3 enriched (algae-fed) chicken meat and three enriched eggs, 6 months (n = 161) Evidence B source
Diastolic BP -3.1 mm Hg (98.75% CI -5.8 to -0.3); omega-3 index +1.7%
A 2021 Cochrane review of 33 placebo-controlled trials with 1,848 adults with major depression found omega-3 gave a small benefit on symptoms (SMD -0.40), with very low certainty. — adults with major depressive disorder in randomized trials of n-3 PUFA vs placebo (n = 1848) Evidence A source
SMD -0.40 (95% CI -0.64 to -0.16), 33 studies, very low-certainty evidence
In the same Cochrane review, omega-3 did not raise remission rates in major depression (OR 1.13, 8 trials, 609 people). — adults with major depressive disorder (n = 609) Evidence A source
Remission OR 1.13 (95% CI 0.74 to 1.72), 8 studies, low certainty; response OR 1.20 (0.80 to 1.79), 17 studies, 794 participants
A 2019 meta-analysis of 26 trials with 2,160 people found benefit only for EPA-rich formulas (60% EPA or more, up to 1 g a day), not for DHA-rich ones. — participants in double-blind placebo-controlled trials of omega-3 for depression (n = 2160) Evidence A source
Overall SMD -0.28; EPA-pure SMD -0.50; EPA-major (60% EPA or more) SMD -1.03 at EPA up to 1 g/d; DHA-pure and DHA-major no benefit
For prevention, a meta-analysis of 31 trials with 41,470 people found long-chain omega-3 had little or no effect on the risk of depression symptoms (RR 1.01). — adults with or without depression or anxiety randomized to more long-chain omega-3 for 24 weeks or longer (n = 41470) Evidence A source
Depression symptoms RR 1.01 (95% CI 0.92 to 1.10), median 0.95 g/d for 12 months; anxiety SMD 0.15 (0.05 to 0.26); moderate-quality evidence
For anxiety, a 2024 dose-response meta-analysis of 23 trials with 2,189 adults found the largest improvement at 2 g a day and no effect below 2 g a day. — adults in randomized trials of omega-3 supplementation measuring anxiety symptoms (n = 2189) Evidence A source
Per 1 g/d SMD -0.70 (95% CI -1.17 to -0.22), low GRADE; at 2 g/d SMD -0.93 (-1.85 to -0.01); below 2 g/d no effect
A 2020 Cochrane review of 86 trials found that long-chain omega-3 supplements made little or no difference to cardiovascular events overall (RR 0.96) or to death from any cause (RR 0.97). — adults at varying cardiovascular risk in RCTs lasting at least 12 months, mainly high-income countries (n = 86 RCTs, 162796 participants) Evidence A source
Cardiovascular events RR 0.96 (95% CI 0.92 to 1.01, high certainty); all-cause mortality RR 0.97 (0.93 to 1.01, high certainty); cardiovascular mortality RR 0.92 (0.86 to 0.99, moderate certainty)
The same Cochrane review found omega-3 may slightly cut coronary heart disease events (RR 0.91), so about 167 people would need to take it for one to avoid an event. — adults in RCTs of long-chain omega-3 lasting at least 12 months (n = 32 RCTs, 134116 participants (CHD events)) Evidence A source
CHD events RR 0.91 (95% CI 0.85 to 0.97), NNTB 167; CHD mortality RR 0.90 (0.81 to 1.00), NNTB 334; both low certainty
A 2019 meta-analysis of 13 trials with 127,477 people found marine omega-3 supplements lowered heart attack risk by 8% and coronary death by 8%, even without the REDUCE-IT trial. — participants of 13 large RCTs of marine omega-3 supplementation, mean treatment 5.0 years (n = 13 RCTs, 127477 participants) Evidence A source
Excluding REDUCE-IT: MI RR 0.92 (0.86 to 0.99); CHD death RR 0.92 (0.86 to 0.98); total CVD RR 0.97 (0.94 to 0.99); linear dose-response for total CVD
A 2021 meta-analysis of 40 trials with 135,267 people found EPA and DHA cut heart attacks by 13% (NNT 272), with larger effects at higher doses. — participants of RCTs of EPA/DHA supplementation published before August 2019 (n = 40 studies, 135267 participants) Evidence A source
MI RR 0.87 (0.80 to 0.96), NNT 272, high certainty; CHD events RR 0.90 (0.84 to 0.97), NNT 192; CVD events RR 0.95 (0.90 to 1.00); dose dependent for CVD events and MI
A 2024 meta-analysis of 18 trials with 134,144 people found omega-3 cut heart attacks by 11% and cardiovascular death by 8%. — participants in primary and secondary prevention RCTs receiving DHA + EPA, EPA alone, or control (n = 18 RCTs, 134144 participants) Evidence A source
MI 0.89 (0.81 to 0.98); cardiovascular death 0.92 (0.85 to 0.99); revascularisation 0.90 (0.84 to 0.98)
A 2023 meta-analysis of 9 trials with 2,070 people with osteoarthritis found omega-3 supplements eased pain slightly (SMD -0.29) compared with placebo. — patients with osteoarthritis in RCTs of n-3 PUFA supplements vs placebo (n = 2070) Evidence A source
Pain SMD -0.29 (95% CI -0.47 to -0.11)
A 2007 meta-analysis of 17 trials found 3 to 4 months of omega-3 reduced patient-reported joint pain (SMD -0.26), morning stiffness and tender joint counts in inflammatory joint pain. — patients with rheumatoid arthritis or joint pain from inflammatory bowel disease and dysmenorrhea (n = 17 RCTs) Evidence A source
Patient-assessed pain SMD -0.26 (95% CI -0.49 to -0.03); morning stiffness -0.43 (-0.72 to -0.15); painful/tender joints -0.29 (-0.48 to -0.10); NSAID use -0.40 (-0.72 to -0.08); physician-assessed pain not significant
A 2022 umbrella meta-analysis of 32 meta-analyses found omega-3 supplements lowered the inflammation marker CRP (effect size -0.40), and also TNF-alpha and IL-6, across health conditions. — adults with different health conditions in meta-analyses of n-3 PUFA supplementation (n = 32 meta-analyses) Evidence A source
CRP ES -0.40 (95% CI -0.56 to -0.24); TNF-alpha -0.23 (-0.37 to -0.08); IL-6 -0.22 (-0.39 to -0.05)
In VITAL-Pain, 19,611 older US adults taking 1 g of omega-3 a day for a median 5.3 years reported pain as often and as severely as those on placebo (OR 0.99). — middle-aged and older US adults in VITAL with complete end-of-trial pain data (n = 19611) Evidence B source
OR for higher pain prevalence or severity 0.99 (95% CI 0.94 to 1.04)
A 2018 Cochrane review found omega-3 in pregnancy cut preterm birth by 11% and early preterm birth before 34 weeks by 42%, with high-quality evidence. — 19,927 women at low, mixed or high risk in 70 RCTs of omega-3 LCPUFA supplements or foods vs placebo or no omega-3 (n = 10,304) Evidence A source
Preterm <37 wk RR 0.89 (95% CI 0.81 to 0.97; 26 RCTs, 10,304); early preterm <34 wk RR 0.58 (0.44 to 0.77; 9 RCTs, 5204); GRADE high
The same Cochrane review found omega-3 lengthened pregnancy by about 1.7 days on average and may have lowered preeclampsia risk by 16%, on low-quality evidence. — pregnant women in RCTs of omega-3 LCPUFA vs no omega-3 (n = 12,517) Evidence A source
Gestational length MD +1.67 days (95% CI 0.95 to 2.39; 41 trials); pre-eclampsia RR 0.84 (0.69 to 1.01; 20 trials, 8306), not significant
A 2023 meta-analysis of 59 trials linked omega-3 in pregnancy with 16% lower risk of preeclampsia and 14% lower risk of preterm birth. — pregnant women in RCTs or quasi-RCTs of oral omega-3 (DHA, EPA or ALA) at least twice a week, 1990-2020 (n = 21,919) Evidence A source
Preeclampsia RR 0.84 (95% CI 0.74 to 0.96; 24 comparisons, 21,919); preterm RR 0.86 (0.77 to 0.95; 15,510)
In a US trial of 350 women, 600 mg/day of DHA from mid-pregnancy lengthened pregnancy by 2.9 days and raised birth weight by 172 g, with no safety concerns. — 350 pregnant women in Kansas City taking DHA or placebo capsules from <20 weeks to birth; mean DHA intake 469 mg/day (n = 350) Evidence B source
Gestation +2.9 days (P = 0.041); birth weight +172 g (P = 0.004); fewer births <34 weeks (P = 0.025)
In a Danish trial of 736 women, 2.4 g/day of fish oil omega-3 in the third trimester prolonged pregnancy by 2 days and raised birth weight by 97 g. — pregnant women from the COPSAC2010 cohort, 2.4 g n-3 LCPUFA or olive oil daily from weeks 22-26 until 1 week after birth; 699 pairs analyzed (n = 699) Evidence B source
Median gestation 282 vs 280 days (P = 0.02); birth weight 3601 vs 3504 g (P = 0.02)
A 2019 meta-analysis of 13 trials with 625 people found fish oil supplements did not significantly lower psoriasis severity (PASI mean difference -0.28). — patients with psoriasis in RCTs of fish oil supplements; 3 RCTs (337 participants) with usable data (n = 625) Evidence A source
PASI mean difference -0.28 (95% CI -1.74 to 1.19), not significant
A 2025 network meta-analysis of 19 trials with 1,658 people with pattern hair loss found an omega-3 and omega-6 supplement scored better than placebo in blinded doctor ratings, along with several other supplements. — patients with androgenetic alopecia in RCTs of dietary supplements (16 supplements) (n = 1658) Evidence A source
Omega 3&6 among supplements with higher blinded hair regeneration scores; no differences in terminal-to-vellus ratio
In a 10 week trial of 45 people with mild to moderate acne, 2,000 mg a day of EPA and DHA reduced inflammatory and non inflammatory lesions. — 45 participants with mild to moderate acne; omega-3 (2,000 mg EPA+DHA), borage oil, or control (n = 45) Evidence B source
Significant decrease in inflammatory and non-inflammatory lesions after 10 weeks; size not given in abstract
In a 3 month trial of 79 fair skinned women, 5 g a day of an EPA rich oil did not significantly reduce sun induced suppression of skin immunity overall (difference 6.9%). — 79 nickel-allergic women aged 22-60 years, phototype I or II, 5 g n-3 PUFA lipid (70% EPA, 10% DHA) or control daily for 3 months (n = 79) Evidence B source
Mean difference 6.9% (95% CI -2.1% to 15.9%), not significant; 11% (0.5% to 21.4%) at 3.8 J/cm2 only
A 2023 dose-response meta-analysis of 90 trials found 2 g a day of EPA plus DHA lowered triglycerides by about 43 mg/dL, and 3 g a day by about 69 mg/dL. — participants in randomized controlled trials of DHA, EPA or both, published 1990 to 2022, mean age 25.7 to 70.0 years (n = 90 RCTs, 72598 participants) Evidence A source
TG -42.61 mg/dL (95% CI -53.41 to -31.80) at 2 g/d; -68.90 mg/dL (95% CI -98.40 to -39.40) at 3 g/d; near-linear dose-response
A 2020 Cochrane review of 86 trials found more EPA and DHA cut triglycerides by about 15%, with high certainty, but had little or no effect on other blood lipids. — adults at varying cardiovascular risk in RCTs lasting at least 12 months, mainly in high-income countries (n = 86 RCTs, 162796 participants) Evidence A source
TG about -15%, dose-dependent (high-certainty evidence); little or no effect on other lipids, adiposity or blood pressure
Across 16 trials, fish oil supplements lowered triglycerides by 25.5 mg/dL compared with corn oil. — participants in randomized controlled trials comparing fish oil supplements with corn oil (n = 16 RCTs) Evidence A source
TG WMD -25.50 mg/dL (95% CI -42.44 to -8.57); HDL +2.54 mg/dL (95% CI 0.55 to 4.52); no significant change in TC or LDL
A network meta-analysis of 64 trials found each gram of omega-3 from fish oil lowered triglycerides by about 9 mg/dL, the same as krill oil. — participants in randomized controlled trials of krill oil or fish oil (n = 64 RCTs) Evidence A source
Per 1 g n-3: TG -8.971 mg/dL (95% CrI 2.27 to 14.04) for fish oil, -9.838 mg/dL (95% CrI 0.72 to 19.40) for krill oil; krill vs fish oil TG WMD -4.07 (95% CI -15.22 to 7.08), not significant
A meta-analysis of 21 RCTs with 1,652 overweight or obese adults found fish oil did not lower body weight compared with control. — adults 18 years or older with overweight or obesity; fish oil capsules, median 1.92 g/day n-3 PUFA, median 12 weeks (n = 1,652) Evidence A source
Body weight SMD -0.07 (95% CI -0.21 to 0.07, P = 0.31), 21 comparisons, I2 25.2%; fish oil alone SMD -0.004 (-0.20 to 0.19)
In the same meta-analysis, fish oil combined with a diet or exercise program reduced waist circumference slightly (SMD -0.23). — overweight or obese adults in randomized placebo-controlled trials (n = 1,652) Evidence A source
Waist circumference SMD -0.23 (95% CI -0.40 to -0.06, P = 0.008) with lifestyle program
A meta-analysis of 11 RCTs with 617 overweight or obese people found no difference in weight loss between omega-3 and placebo (WMD 0 lb (0.00 kg), 9 studies). — overweight and obese adults in RCTs of n-3 PUFA supplements vs placebo (n = 617) Evidence A source
Weight WMD 0 lb (95% CI -0.93 to 0.95; metric: 0.00 kg, -0.42 to 0.43), 9 studies
In an RCT of 128 adults with BMI 26 to 40, adding 3 g a day of EPA+DHA to diet and exercise counseling for 24 weeks gave no extra weight loss. — overweight and obese adults (BMI 26 to 40) receiving dietary and exercise counseling; 5 capsules daily, 3.0 g EPA+DHA at 5:1 vs placebo (n = 128) Evidence B source
Weight change -11 lb (95% CI -13 to -9.7; metric: -5.2 kg, -6.0 to -4.4) omega-6.6 vs -13 lb (-15 to -11; metric: 3 vs -5.8 kg, -6.7 to -5.1) placebo; difference 1.3 lb (0.61 kg), P = 0.29; 27% dropout
In a double-blind RCT, fish oil capsules taken with a very-low-energy diet for 4 weeks and then 10 weeks of maintenance did not add to weight loss. — obese adults on a 4-week very-low-energy diet then 10-week maintenance; 6 g/day capsules (420 mg EPA, 1,620 mg DHA) vs monounsaturated oil (n = 32) Evidence B source
No significant effect on weight loss or weight maintenance over 14 weeks
A meta-analysis of 10 RCTs with 558 people found omega-3 taken with vitamin E for 6 to 16 weeks did not change body weight or BMI. — adults in RCTs of omega-3 1,000 to 4,000 mg/day plus vitamin E 400 IU vs control (n = 558) Evidence A source
Body weight WMD 0.31 lb (95% CI -0.29 to 0.93; metric: 0.14 kg, -0.13 to 0.42); BMI WMD 0.08 (-0.01 to 0.16); BMI rose in some subgroups (over 8 weeks, women over 50)
A Cochrane meta-analysis of 45 trials with 143,693 people found that taking more EPA and DHA, mostly as capsules, made little or no difference to deaths from any cause (RR 0.97). — 86 RCTs, 162,796 adults at varying cardiovascular risk, 12 to 88 months (n = 143693) Evidence A source
All-cause mortality RR 0.97 (0.93 to 1.01), CV events RR 0.96 (0.92 to 1.01), stroke RR 1.02 (0.94 to 1.12)
The same Cochrane review found EPA and DHA may slightly cut coronary heart disease events by 9%, so 167 people would need to take them for one to benefit. — 32 RCTs, 134,116 participants (n = 134116) Evidence A source
CHD events RR 0.91 (0.85 to 0.97), NNTB 167, low-certainty evidence
Across 16 trials, fish oil supplements lowered triglycerides by 25.5 mg/dL and raised HDL by 2.5 mg/dL compared with corn oil, with no change in LDL. — 16 RCTs, 491 participants (n = 491) Evidence A source
TG WMD -25.50 mg/dL (-42.44 to -8.57), HDL +2.54 mg/dL (0.55 to 4.52), TC and LDL no change

Safety, limits and interactions

In the same 71-trial analysis, combined EPA plus DHA doses above 3 g a day gave weaker or no average blood pressure change, so more fish oil did not mean more lowering on average. — adults in 71 randomized controlled trials; doses 0.2 to 15 g/day (n = 71 trials) Evidence A source
Doses >3 g/day associated with weaker or null BP changes in both SBP and DBP models
Across 7 large trials with 81,210 people, marine omega-3 supplements raised the risk of atrial fibrillation by 25%, and by 49% in trials testing more than 1 g a day. — 81,210 participants of 7 cardiovascular outcome RCTs, mean age 65, follow-up 4.9 years (n = 81210) Evidence A source
AF HR 1.25 (95% CI 1.07 to 1.46); >1 g/day HR 1.49 (1.04 to 2.15); per 1 g/day HR 1.11
According to an AHRQ review, 2 trials adding 3 to 5 g a day of omega-3 to ACE inhibitor treatment found no extra lowering of systolic or diastolic blood pressure. — adults taking ACE inhibitors in 2 parallel-arm trials, omega-3 3 to 5 g/day, 6 to 25 weeks (n = 2 trials) Evidence E source
SBP difference 0 and -1.00 mm Hg; DBP -1.40 and -2.00 mm Hg; pooled no difference
In VITAL-DEP, 1 g of fish oil a day for 5.3 years did not raise gastrointestinal bleeding, bruising or stomach upset compared with placebo. — US adults aged 50 or older; 1 g/d fish oil vs placebo (n = 18353) Evidence B source
GI bleeding 2.6% vs 2.7%; easy bruising 24.8% vs 25.1%; stomach upset 35.2% vs 35.1%; suicide 0.02% vs 0.01%
Across 24 trials in major depression, adverse events were similar with omega-3 and placebo (OR 1.27), though a modest increase cannot be ruled out. — adults with major depressive disorder (n = 1503) Evidence A source
Adverse events OR 1.27 (95% CI 0.99 to 1.64), 24 studies, very low certainty
A meta-analysis of 11 trials with 120,643 patients found omega-3 did not raise bleeding overall (RR 1.09), but high-dose purified EPA added about 0.6% absolute risk. — patients in randomized trials of omega-3 PUFA, mostly cardiovascular (n = 120643) Evidence A source
Bleeding rate ratio 1.09 (95% CI 0.91 to 1.31); high-dose purified EPA about 50% relative and 0.6% absolute increase
A 2026 meta-analysis of 35 trials with 114,592 people found EPA plus DHA above 1.5 g a day raised atrial fibrillation risk in people at high cardiovascular risk (OR 1.43). — adults 50 or older in randomized trials of at least 500 mg/d EPA plus DHA for 12 months or more (n = 114592) Evidence A source
High risk, high dose OR 1.43 (95% CI 1.14 to 1.79), absolute difference 0.8%; other groups OR 1.03 to 1.07, not significant
In REDUCE-IT, more people on 4 g a day of purified EPA were hospitalized for atrial fibrillation (3.1% vs 2.1%), and serious bleeding was 2.7% vs 2.1%. — statin-treated patients with raised triglycerides and high cardiovascular risk (n = 8179) Evidence B source
AF or flutter hospitalization 3.1% vs 2.1% (P=0.004); serious bleeding 2.7% vs 2.1% (P=0.06)
In the STRENGTH trial of 13,078 high-risk statin users, 4 g a day of an EPA plus DHA mix did not reduce cardiovascular events (12.0% vs 12.2%) and caused more gut side effects (24.7% vs 14.7%). — statin-treated patients with high cardiovascular risk, hypertriglyceridemia and low HDL-C, 22 countries (n = 13078) Evidence B source
Primary end point 12.0% vs 12.2%, HR 0.99 (95% CI 0.90 to 1.09); gastrointestinal adverse events 24.7% vs 14.7%
A 2021 meta-analysis of 7 trials with 81,210 people found marine omega-3 supplements raised atrial fibrillation risk by 25%, and by 49% at doses above 1 g a day. — patients in cardiovascular outcome RCTs of marine omega-3 (>= 500 people, >= 1 year), mean age 65 (n = 7 RCTs, 81210 participants) Evidence A source
AF HR 1.25 (95% CI 1.07 to 1.46); >1 g/d HR 1.49 (1.04 to 2.15); <=1 g/d HR 1.12 (1.03 to 1.22); HR 1.11 per extra 1 g/d
A 2026 meta-analysis of 35 trials with 114,592 people found raised atrial fibrillation risk only in high-risk people taking more than 1.5 g a day (OR 1.43, about 0.8% more in absolute terms). — people aged 50 or older in RCTs of >= 500 mg/d EPA/DHA for >= 12 months (n = 35 RCTs, 114592 participants) Evidence A source
High CVD risk and >1500 mg/d: AF OR 1.43 (95% CI 1.14 to 1.79), absolute risk difference 0.8%; other groups OR 1.03 to 1.07, not significant
A 2024 meta-analysis of 15 trials judged prescription omega-3 acid ethyl ester to have a good safety profile and prescription EPA ethyl ester a high risk of bleeding. — participants in RCTs of omega-3 supplements for cardiovascular prevention (n = 15 RCTs) Evidence A source
Prescription omega-3 acid ethyl ester: good safety profile; prescription EPA ethyl ester: high risk of bleeding (qualitative)
EFSA concluded that supplemental EPA plus DHA up to 5 g a day raises no safety concerns for adults. — adults Evidence E source
No safety concern up to 5 g/day EPA+DHA combined (bleeding, glucose regulation, immune function)
Across 7 large trials with 81,210 people, marine omega-3 supplements raised the risk of atrial fibrillation by 25% (HR 1.25). — participants in RCTs of cardiovascular outcomes with at least 500 people and 1 year follow-up; mean age 65 (n = 81210) Evidence A source
AF HR 1.25 (95% CI 1.07 to 1.46), 2,905 AF cases
In the VITAL trial of 25,871 US adults taking 1 g of omega-3 a day for a median 5.3 years, no excess bleeding or other serious adverse events were seen. — men 50 or older and women 55 or older in the US; 1 g/day marine n-3 fatty acids vs placebo (n = 25871) Evidence B source
No excess risks of bleeding or other serious adverse events
NCCIH says side effects of omega-3 supplements are usually mild, such as unpleasant taste, bad breath, headache, heartburn, nausea and diarrhea. — people using omega-3 supplements Evidence E source
Mild side effects: taste, breath, sweat odor, headache, gastrointestinal symptoms
In the Cochrane review, omega-3 probably raised the chance of pregnancy running past 42 weeks from 1.6% to 2.6%. — pregnant women in 6 RCTs reporting prolonged gestation (n = 5141) Evidence A source
Prolonged gestation >42 wk RR 1.61 (95% CI 1.11 to 2.33); moderate-quality evidence
In ORIP, fish oil raised the share of very large babies for gestational age by 30% and caused more minor stomach upsets, with no difference in serious adverse events. — women in the ORIP trial, fish oil 900 mg n-3 LCPUFA daily vs vegetable oil (n = 5486) Evidence B source
Very large for gestational age adjusted RR 1.30 (95% CI 1.02 to 1.65); more minor gastrointestinal disturbances; serious adverse events no different
A meta-analysis of 21 trials with 24,460 people found prescription omega-3 was associated with more skin reactions (rash, itching, eczema) and fishy taste than control. — participants in RCTs of marketed prescription omega-3 products vs control (n = 24460) Evidence A source
More treatment-related skin abnormalities (p < 0.001) and dysgeusia (p = 0.011); no definite serious adverse event
According to EFSA, supplemental EPA plus DHA up to 5 g a day raises no safety concerns for adults. — adults in the EU Evidence E source
EPA+DHA up to 5 g/day supplemental: no safety concern; no upper limit set
The 2023 dose-response meta-analysis found EPA plus DHA did not lower LDL cholesterol, which rose slightly, by about 2.9 mg/dL, at 1.75 g a day. — participants in randomized controlled trials of DHA plus EPA (n = 80 RCTs for LDL-C) Evidence A source
J-shaped LDL-C curve peaking at 1.75 g/d: LDL-C +2.91 mg/dL (95% CI 0.34 to 5.47); HDL-C +3.48 mg/dL (95% CI 1.09 to 5.86)
Across 8 large trials with 83,112 people, omega-3 supplements raised atrial fibrillation risk by 24% (4.0% against 3.3%). — participants in cardiovascular outcome RCTs with at least 1000 people and at least 1 year of follow-up (n = 83112) Evidence A source
AF 4.0% vs 3.3%, RR 1.24 (95% CI 1.11 to 1.38); <=1 g/d RR 1.12 (1.04 to 1.21); >1 g/d RR 1.51 (1.26 to 1.80); no rise in stroke (RR 1.04)
Across 11 trials with 120,643 people, omega-3 did not raise overall bleeding. — patients in randomized clinical trials receiving omega-3 PUFAs (n = 120643) Evidence A source
Bleeding RR 1.09 (95% CI 0.91 to 1.31); high-dose purified EPA: 50% relative, 0.6% absolute increase; risk linked to EPA dose, not to antiplatelet use
A meta-analysis of 21 trials of prescription omega-3 found more fishy taste and skin rashes than on control. — participants in RCTs of marketed prescription omega-3 fatty acid products (n = 24460) Evidence A source
More dysgeusia (p = 0.011) and skin abnormalities (p < 0.001); EPA/DHA combination products: more belching and nausea, LDL-C +4.106 mg/dL (p = 0.009)
A 2012 AHRQ review found low-grade evidence that adding omega-3 to statins changed neither LDL, HDL, clotting tests nor bleeding time versus statins alone. — adults taking cardiovascular drugs (statins) in randomized trials (n = 57 RCTs and 2 controlled trials (whole key question)) Evidence A source
Omega-3 plus statins vs statins alone: no difference in HDL-C, LDL-C, coagulation parameters or bleeding time (low strength of evidence)
Across 8 large trials with 83,112 people, omega-3 supplements raised atrial fibrillation risk by 24% (4.0% against 3.3%). — participants in cardiovascular outcome RCTs with at least 1000 people and at least 1 year of follow-up (n = 83112) Evidence A source
AF 4.0% vs 3.3%, RR 1.24 (95% CI 1.11 to 1.38); <=1 g/d RR 1.12 (1.04 to 1.21); >1 g/d RR 1.51 (1.26 to 1.80)
Across 11 trials with 120,643 people, omega-3 did not raise overall bleeding. — patients in randomized clinical trials receiving omega-3 PUFAs (n = 120643) Evidence A source
Bleeding RR 1.09 (95% CI 0.91 to 1.31); high-dose purified EPA: 50% relative, 0.6% absolute increase
In a trial of 25,871 US adults over a median 5.3 years, omega-3 supplements did not significantly lower major cardiovascular events (HR 0.92), and no excess bleeding was seen. — 25,871 US men 50 and older and women 55 and older, median 5.3 years (n = 25871) Evidence B source
Major CV events HR 0.92 (0.80 to 1.06), invasive cancer HR 1.03 (0.93 to 1.13), total MI HR 0.72 (0.59 to 0.90, secondary)
Across 7 large trials with 81,210 people, marine omega-3 supplements raised the risk of atrial fibrillation by 25%, and by 49% at doses above 1 g a day. — 7 RCTs, 81,210 patients, mean age 65, weighted follow-up 4.9 years (n = 81210) Evidence A source
AF HR 1.25 (1.07 to 1.46); >1 g/d HR 1.49 (1.04 to 2.15); per extra 1 g HR 1.11 (1.06 to 1.15)
An updated meta-analysis of 35 trials found higher atrial fibrillation risk only in people at high cardiovascular risk taking more than 1,500 mg EPA and DHA a day, an absolute increase of 0.8%. — 35 RCTs, 114,592 participants aged 50 and older, at least 12 months, 500 mg/d or more (n = 114592) Evidence A source
High risk, high dose OR 1.43 (1.14 to 1.79), absolute difference 0.8% (0.40% to 1.1%); low-dose groups OR 1.03 to 1.07, not significant
Observational data from 95 spinal surgery patients found no extra blood loss in the 16 who had taken omega-3 or fish oil until about 2 days before surgery. — 95 consecutive lumbar decompression patients, 16 on omega-3 supplements (n = 95) Evidence C source
Blood loss 4.7 vs 5.2 fl oz (138 vs 154 mL) (P = 0.53), no bleeding complications in the omega-3 group
NIH reports that EFSA considers long-term EPA and DHA supplements safe up to about 5 g a day combined, and that the FDA has concluded supplements providing no more than 5 g a day are safe when used as recommended. — adults taking EPA and DHA supplements, US and EU agency positions Evidence E source
EFSA: long-term EPA+DHA supplements up to about 5 g/day appear safe; FDA: supplements providing no more than 5 g/day EPA+DHA are safe when used as recommended
NIH notes that fish oil might prolong clotting times when taken with warfarin, although most research finds 3 to 6 g a day does not significantly change anticoagulation, and labels of omega-3 drugs advise periodic INR checks. — people taking warfarin and similar anticoagulants Evidence E source
Fish oil might raise INR with warfarin; 3-6 g/day mostly no significant effect on anticoagulant status; INR monitoring advised on omega-3 drug labels
A meta-analysis of 11 randomized trials with 120,643 patients found no overall rise in bleeding with omega-3 fats (RR 1.09, 95% CI 0.91 to 1.31), while high-dose purified EPA raised bleeding risk by 50% in relative terms, 0.6% in absolute terms. — patients in 11 randomized clinical trials of omega-3 fatty acids (n = 120643) Evidence A source
Bleeding RR 1.09 (95% CI 0.91 to 1.31); high-dose purified EPA: 50% higher relative risk, absolute increase 0.6%
NIH warns that preformed vitamin A above the upper limit can cause birth defects of the eye, skull, lungs and heart. Women who are or might be pregnant, or are breastfeeding, are advised not to take more than 3,000 mcg RAE a day from supplements. — women who are or might be pregnant and lactating women Evidence E source
Preformed vitamin A above the UL can cause birth defects (eye, skull, lungs, heart); advice not to take more than 3,000 mcg RAE (10,000 IU) a day from vitamin A supplements in pregnancy or lactation

What people believe that the data does not support

According to the US FDA in 2019, labels may say EPA and DHA may help lower blood pressure only with the disclaimer that the evidence is inconsistent and inconclusive, and only at 0.8 g or more per serving. — US foods and dietary supplements with at least 0.8 g EPA and DHA per serving Evidence E source
Qualified health claim under enforcement discretion; evidence 'inconsistent and inconclusive'
The European Union authorizes the claim that DHA and EPA contribute to the maintenance of normal blood pressure. — European Union food labeling Evidence E source
Authorized health claim (EU register POL-HC-8354)
WFSBP and CANMAT guidelines (2022) recommend omega-3 as an add-on to antidepressants for unipolar depression, but not as a stand-alone treatment. — adults with unipolar depression Evidence E source
Adjunctive omega-3 recommended (+++); monotherapy omega-3 not currently recommended (+/-); weak support for bipolar depression (+)
NCCIH says it is uncertain whether omega-3 supplements help depression. — people with depression Evidence E source
Uncertain benefit
NCCIH notes reviews suggesting EPA may beat DHA and that omega-3 may work best alongside antidepressants rather than instead of them. — people with depression Evidence E source
EPA over DHA; adjunct rather than replacement
The American Heart Association (2017) judged omega-3 supplements reasonable for people with existing coronary heart disease, to prevent coronary death (Class IIa). — patients with prevalent coronary heart disease Evidence E source
Class IIa recommendation for secondary prevention of CHD death; Class IIa also for heart failure with reduced ejection fraction
The same AHA advisory said omega-3 supplements are not indicated to prevent cardiovascular disease in people with or at risk for diabetes (Class III, no benefit). — patients with diabetes mellitus or prediabetes Evidence E source
Class III: No Benefit
The US FDA allows a qualified claim that EPA and DHA may reduce coronary heart disease risk, but requires saying the evidence is inconsistent and inconclusive. — US food and supplement labeling Evidence E source
Qualified health claim (enforcement discretion), with mandatory disclaimer
The EU authorizes the claim that EPA and DHA contribute to the normal function of the heart. — EU food labeling Evidence E source
Authorized health claim (conditions of use in Regulation (EU) No 432/2012, not quoted here)
NCCIH reports that omega-3-rich foods may improve pain and swollen and tender joints and might be an appropriate addition to drug therapy for rheumatoid arthritis. — people with rheumatoid arthritis (n = 30 studies, 1,420 participants (cited review)) Evidence E source
May improve pain and swollen and tender joints; adjunct to drug therapy
The EU did not authorize the label claim that omega-3 EPA and DHA help maintain healthy joints. — EU food labeling Evidence E source
Claim non-authorized
A 2024 clinical practice guideline advises women of childbearing age to get at least 250 mg/day of DHA plus EPA, with an extra 100 to 200 mg/day of DHA in pregnancy. — women of childbearing age and pregnant women Evidence E source
At least 250 mg/day DHA+EPA before pregnancy; +100-200 mg/day DHA in pregnancy
The same 2024 guideline advises 600 to 1000 mg/day of DHA plus EPA for pregnant women with low omega-3 intake or blood levels, from about 20 to 37 weeks. — pregnant women with low DHA intake and/or low DHA blood levels Evidence E source
600-1000 mg/day DHA+EPA or DHA alone, starting by about 20 weeks, until about 37 weeks or birth
NCCIH cites dermatology guidelines that find inconsistent to no evidence to recommend fish oils for atopic dermatitis. — people with atopic dermatitis Evidence E source
Not recommended for lack of evidence
According to a 2019 American Heart Association advisory, 4 g a day of EPA plus DHA cuts very high triglycerides by at least 30%, with a rise in LDL that EPA alone did not cause. — patients with very high triglycerides (500 mg/dL or more), US clinical guidance Evidence E source
TG -30% or more with 4 g/d in very high TG; LDL-C rises with EPA+DHA, not with EPA-only
The American Heart Association concluded in 2019 that prescription omega-3 at 4 g a day is an effective and safe way to lower triglycerides, alone or with other lipid-lowering drugs. — adults with hypertriglyceridemia, US clinical guidance Evidence E source
Prescription n-3 FA 4 g/d (>3 g/d EPA+DHA) recommended for TG lowering; cites 25% fewer major cardiovascular events with EPA-only in REDUCE-IT
According to EFSA, supplemental EPA plus DHA up to 5 g a day raises no safety concerns for adults. No upper limit was set. — adults in the EU Evidence E source
EPA+DHA up to 5 g/day supplemental: no safety concern; data insufficient to set a UL
The EU authorizes the claim that DHA and EPA contribute to the maintenance of normal blood triglyceride levels. — EU food labeling Evidence E source
Authorized health claim (conditions of use in Regulation (EU) No 432/2012, not quoted here)
According to EFSA, supplemental EPA plus DHA up to 5 g a day raises no safety concerns for adults. No upper limit was set. — adults in the EU Evidence E source
EPA+DHA up to 5 g/day supplemental: no safety concern; data insufficient to set a UL
The EU rejected the claim that fish oil EPA and DHA contribute to thinning the blood. — EU food labeling Evidence E source
Non-authorized claim

Who this works differently for

People with hypertension (systolic 140 mm Hg or more) had larger falls in both systolic and diastolic pressure from EPA plus DHA than people without hypertension, in the 71-trial dose-response analysis. — subgroups by hypertension status (SBP >= 140 mm Hg) in 71 randomized controlled trials (n = 71 trials) Evidence A source
Greater SBP and DBP reductions in hypertension than without hypertension
In the 70-trial meta-analysis, the largest falls were in untreated hypertension (systolic -4.51, diastolic -3.05 mm Hg), and normotensive people saw only about 1.25 mm Hg systolic. — untreated hypertensive and normotensive subjects in randomized controlled trials of EPA+DHA (n = 70 trials) Evidence A source
Untreated hypertensive SBP -4.51 (95% CI -6.12 to -2.83), DBP -3.05 (-4.35 to -1.74); normotensive SBP -1.25 (-2.05 to -0.46), DBP -0.62 (-1.22 to -0.02)
A meta-analysis of 20 randomized trials found EPA alone lowered systolic pressure by 2.6 mm Hg, while DHA lowered diastolic pressure by 3.1 mm Hg in people with dyslipidemia. — 20 randomized controlled trials of EPA or DHA supplementation (n = 20 trials) Evidence A source
EPA SBP WMD -2.6 mm Hg (95% CI -4.6 to -0.5); dyslipidemia SBP -3.8; DHA DBP -3.1 (-5.9 to -0.2) in dyslipidemia
In a triple-blind trial in 64 people with hypertension, 3 weeks of compound fish oil capsules did not change blood pressure compared with corn oil. — 64 hypertensive patients, 32 per group, compound fish oil (omega-3 with resveratrol, astaxanthin, CoQ10) vs corn oil, 2 capsules a day, 3 weeks (n = 64) Evidence B source
No significant difference in blood pressure; coronary diastolic flow velocity rose (EDV +1.95, PDV +2.95)
In the VITAL-DEP trial of 18,353 US adults aged 50 or older, 1 g of fish oil a day for 5.3 years slightly raised depression risk versus placebo (HR 1.13). — US adults aged 50 or older without clinically relevant depressive symptoms at baseline; 1 g/d fish oil (465 mg EPA, 375 mg DHA) vs placebo (n = 18353) Evidence B source
13.9 vs 12.3 events per 1000 person-years; HR 1.13 (95% CI 1.01 to 1.26); PHQ-8 mood score difference 0.03 (-0.01 to 0.07)
A 2024 Cochrane review of 5 small trials in children and teens with depression found omega-3 may reduce symptoms (SMD -0.34) but the evidence is very uncertain. — children and adolescents aged 19 or younger with diagnosed depression; 10 to 16 weeks of omega-3 vs placebo (n = 185) Evidence A source
SMD -0.34 (95% CI -0.85 to 0.17), 5 trials, very low certainty; remission OR 1.11 (0.45 to 2.75)
A meta-analysis of 18 trials with 4,052 women found no effect of omega-3 on depressive symptoms during pregnancy, and its authors advise against prescribing it for that purpose. — pregnant and postpartum women in randomized trials of omega-3 PUFA for prevention or treatment of perinatal depression (n = 4052) Evidence A source
Overall SDM -0.236 (95% CI -0.463 to -0.009); pregnancy SDM -0.071; postpartum SDM -0.656 (-1.690 to 0.378)
In a 2025 meta-analysis of anti-inflammatory treatments in older adults with depression, omega-3 gave a small benefit (SMD -0.14). — older adults in randomized trials of anti-inflammatory interventions for depression (n = 31 RCTs) Evidence A source
Omega-3 subgroup SMD -0.14 (95% CI -0.27 to -0.02)
A 2018 meta-analysis of 10 large trials with 77,917 high-risk people found no significant effect of omega-3 supplements on major vascular events, overall or in any subgroup. — 77,917 high-risk individuals in trials of at least 500 people and 1 year, mean age 64.0, EPA 226-1800 mg/d (n = 10 RCTs, 77917 participants) Evidence A source
Any CHD event RR 0.96 (95% CI 0.90 to 1.01); major vascular events RR 0.97 (0.93 to 1.01); no subgroup (prior CHD, diabetes, statin use) benefited
In the VITAL trial of 25,871 older US adults, 1 g a day of marine omega-3 for 5.3 years did not lower major cardiovascular events (HR 0.92, not significant). — men aged 50 or older and women aged 55 or older in the US, general population (primary prevention) (n = 25871) Evidence B source
Major cardiovascular events HR 0.92 (95% CI 0.80 to 1.06), P=0.24
In the ASCEND trial of 15,480 people with diabetes and no heart disease, 1 g a day of omega-3 for 7.4 years did not reduce serious vascular events (8.9% vs 9.2%). — patients with diabetes but without evidence of atherosclerotic cardiovascular disease, UK (n = 15480) Evidence B source
Serious vascular event 8.9% vs 9.2%, rate ratio 0.97 (95% CI 0.87 to 1.08)
In the REDUCE-IT trial of 8,179 statin users with raised triglycerides, 4 g a day of purified EPA (icosapent ethyl) cut major cardiovascular events from 22.0% to 17.2% over 4.9 years. — statin-treated patients with established cardiovascular disease or diabetes plus risk factors, fasting triglycerides 135 to 499 mg/dL (n = 8179) Evidence B source
Primary end point 17.2% vs 22.0%, HR 0.75 (95% CI 0.68 to 0.83); cardiovascular death HR 0.80 (0.66 to 0.98)
A 2017 meta-analysis of 42 trials found marine oil supplements reduced pain in rheumatoid arthritis by a small amount (SMD -0.21, 22 trials) but not significantly in osteoarthritis (5 trials). — patients with arthritis in randomized trials of oral marine oil supplements vs control; 30 trials with complete pain data (n = 42 trials) Evidence A source
Rheumatoid arthritis -0.21 (-0.42 to -0.004), 22 trials; osteoarthritis -0.17 (-0.57 to 0.24), 5 trials, not significant
A 2025 meta-analysis of 41 trials with 3,759 people found omega-3 benefits for chronic pain were significant in rheumatoid arthritis, migraine and mixed pain conditions, but not in osteoarthritis or mastalgia. — adults with chronic pain conditions in RCTs of omega-3 supplements, searched to February 2025 (n = 3759) Evidence A source
Significant for rheumatoid arthritis, migraine, mixed pain; not for osteoarthritis or mastalgia
A meta-analysis of 10 trials in rheumatoid arthritis found at least 2.7 g a day of omega-3 for 3 months or more cut painkiller (NSAID) use (SMD -0.518). — 183 rheumatoid arthritis patients on omega-3 PUFAs (2.7 g/day or more, 3 months or more) and 187 placebo controls (n = 370) Evidence A source
NSAID consumption SMD -0.518 (95% CI -0.915 to -0.121), I2 0%
In the VITAL trial, 1,398 older US adults with chronic knee pain who took 1 g of omega-3 a day for about 5 years had no less knee pain than those on placebo. — VITAL participants with chronic knee pain at baseline, mean age 67.7, 66% women; 1 g/day marine n-3 FA or placebo (n = 1398) Evidence B source
WOMAC pain did not differ at any time point; time-by-treatment P = 0.77; no effect on function or stiffness
In a 2-year RCT of 202 people with knee osteoarthritis, a high dose of fish oil (4.5 g omega-3 a day) was no better than a low dose for pain or cartilage loss. — patients with knee osteoarthritis and regular knee pain; 15 mL/day high-dose fish oil (4.5 g n-3) vs low-dose blend (0.45 g n-3) (n = 202) Evidence B source
Low-dose group had greater improvement in WOMAC pain and function at 2 years; no difference in cartilage volume loss
In women who had a previous preterm birth, a 2015 meta-analysis of 2 trials found omega-3 did not prevent another one. — asymptomatic singleton pregnancies with previous preterm birth, 2 RCTs (n = 1080) Evidence A source
Preterm <37 wk 34.5% vs 39.8%, RR 0.81 (95% CI 0.59 to 1.12); <34 wk RR 0.62 (0.26 to 1.46)
In the US ADORE trial of 1100 women, those who actually took 1000 mg/day of DHA had early preterm birth cut from 3.45% to 1.2%, most clearly in women with low DHA at the start. — 1100 women with singleton pregnancy enrolled before 20 weeks, 200 mg/day DHA plus placebo or 800 mg DHA, adherence by red cell DHA (n = 1100) Evidence B source
Per-protocol Bayesian model: early preterm 3.45% to 1.2% (65% reduction) with adherence to 1000 mg; largest in lowest two quartiles of baseline DHA
A 2020 review of 18 trials with 927 people found fish oil alone did not change psoriasis scores, but added to standard treatment it lowered PASI by 3.92 points. — patients with psoriasis in RCTs of fish oil or omega-3 PUFAs, alone or with conventional treatment (n = 927) Evidence A source
Monotherapy: no effect on PASI (P = 0.47); with conventional treatment: PASI MD -3.92 (95% CI -6.15 to -1.69), lesion area MD -30.00
A 2023 meta-analysis of 6 trials with 1,646 mother and infant pairs found omega-3 in pregnancy did not lower the rate of eczema in children (RR 1.09). — mother-infant pairs in RCTs of prenatal omega-3 PUFA supplementation (n = 1646) Evidence A source
Eczema RR 1.09 (95% CI 0.82 to 1.46); IgE-associated eczema RR 0.67 (0.29 to 1.57)
A 2015 Cochrane review of 8 trials with 3,366 women found omega-3 in pregnancy or breastfeeding lowered medically diagnosed IgE-mediated eczema in children only at 12 to 36 months. — pregnant and/or breastfeeding women supplemented with n-3 LCPUFA and their 3175 children (n = 3366 women) Evidence A source
Reduction in IgE-mediated eczema at 12-36 months only; no difference at other ages; overall limited evidence
In a 6 month randomized study of 120 women with hair loss, a supplement of omega-3, omega-6 and antioxidants improved hair density on photographs more than no supplement. — 120 healthy women with female pattern hair loss, 6 months, supplement vs control (n = 120) Evidence B source
Greater improvement in photographic hair density (P < 0.001); lower telogen percentage (P < 0.001)
In a 2026 trial of 80 young adults with moderate to severe acne on low dose isotretinoin, adding 1 g of fish oil a day for 3 months worked as well as placebo and kept skin hydration better. — participants aged 18-25 years with acne IGA >=3, 10 mg isotretinoin plus 1 g fish oil (n=40) or placebo (n=40), 3 months (n = 80) Evidence B source
Acne count between-group MD -6.0 (95% CI -16.5 to 4.5), non-inferior; smaller fall in corneometer values; smaller TG rise
In the same 2023 meta-analysis, the triglyceride drop kept growing with dose only in people with high blood lipids, and levelled off at about 40 mg/dL in people without. — trials stratified by hyperlipidemia at entry (52 trials with hyperlipidemia, 11 without) (n = 90 RCTs) Evidence A source
Near-linear TG fall with dose in hyperlipidemia; plateau at roughly -40 mg/dL without hyperlipidemia
In 10 trials of people with ischemic heart disease, 1 to 4 g a day of EPA plus DHA lowered triglycerides by 17.5 mg/dL and LDL by 9.4 mg/dL. — adults with ischemic heart disease in RCTs of omega-3 (1-4 g/day EPA + DHA) versus placebo (n = 633) Evidence A source
TG MD -17.53 mg/dL (95% CI -30.64 to -4.41); LDL-C MD -9.43 mg/dL (95% CI -14.20 to -4.65); moderate certainty (GRADE)
In 9 trials of people with HIV on antiretroviral therapy and high triglycerides, EPA plus DHA lowered triglycerides by about 78 mg/dL. — HIV/AIDS patients with hypertriglyceridemia in stable use of antiretroviral therapy (n = 9 RCTs) Evidence A source
TG -77.55 mg/dL (CI -121.85 to -33.25); trials with baseline TG >200 mg/dL: -114.15 mg/dL (CI -162.34 to -65.97)
In an 8-week RCT of 116 people with coronary artery disease and triglycerides above 200 mg/dL, 1 g a day of DHA cut triglycerides by 21.8%. — patients with coronary artery disease and triglycerides greater than 200 mg/dL, mean age 69.4 years (n = 116) Evidence B source
TG -21.8% with 1000 mg DHA and -18.3% with 1252 mg DHA + EPA (both p < 0.001); between-group difference not significant
A meta-analysis of 11 RCTs with 816 women with PCOS found omega-3 did not change body weight or BMI. — women with polycystic ovary syndrome in RCTs of n-3 PUFA vs control (n = 816) Evidence A source
Body weight and BMI no change in the overall analysis
A meta-analysis of 12 RCTs with 1,028 children and teens with overweight found fish oil lowered BMI by about 1 kg/m2 but not body weight or waist size. — overweight or obese children and adolescents in RCTs of fish oil vs control (n = 1,028) Evidence A source
BMI MD -0.96 kg/m2 (95% CI -1.69 to -0.23); body weight P = 0.68; waist circumference P = 0.76
A 2025 GRADE-assessed meta-analysis of 9 studies with 595 children and teens with overweight found omega-3 did not significantly change weight or BMI z-score. — obese or overweight children and adolescents in trials of omega-3 PUFA supplementation (n = 595) Evidence A source
Weight and BMI z-score no significant change; 8 of 9 studies high risk of bias
In people with cancer, a network meta-analysis of 26 RCTs with 1,892 patients found combined DHA and EPA raised body weight and BMI rather than lowering them. — cancer patients in RCTs of EPA alone or DHA plus EPA vs control (n = 1,892) Evidence A source
Body weight SMD 1.29 (95% CI 0.40 to 2.16), moderate confidence; BMI SMD 0.53 (0.04 to 0.92), high confidence; lean body mass no effect
In advanced lung cancer with cachexia, a meta-analysis of 5 trials with 354 patients found omega-3 added about 2.6 lb (1.2 kg) of weight. — patients with advanced non-small cell lung cancer and cancer cachexia (n = 354) Evidence B source
Weight MD +2.7 lb (95% CI 2.3 to 3; metric: 1.22 kg, 1.05 to 1.38); lean body or skeletal mass MD 2.05 (-0.55 to 4.66), not significant
A Cochrane review of 70 trials in pregnancy found omega-3 supplements cut preterm birth before 37 weeks by 11% and early preterm birth before 34 weeks by 42%. — 70 RCTs, 19,927 pregnant women at low, mixed or high risk (n = 19927) Evidence A source
Preterm <37 wk RR 0.89 (0.81 to 0.97); early preterm <34 wk RR 0.58 (0.44 to 0.77); gestation >42 wk RR 1.61 (1.11 to 2.33)

What is still unknown

The Cochrane authors translate that benefit to about 2.5 points on the Hamilton depression scale, below the 3-point change patients would notice. — adults with major depressive disorder in randomized trials of n-3 PUFA vs placebo (n = 1848) Evidence A source
About 2.5 HDRS-17 points (95% CI 1.0 to 4.0); minimal clinically important change 3.0 points
The Cochrane review saw no difference in effect by trial length or omega-3 dose, and found little trial evidence on eating fish itself. — adults in RCTs of long-chain omega-3 lasting 12 to 88 months (n = 86 RCTs) Evidence A source
No effect modification by duration or dose (subgroups and meta-regression); little trial evidence for fish intake
A 2026 meta-analysis of 6 trials with 42,738 people found that among blinded placebo-controlled trials, only 4 g a day of icosapent ethyl (purified EPA) on its own reduced cardiovascular events. — adults with established CVD or other high-risk settings in RCTs of high-dose EPA-dominant omega-3 (>= 1.8 g/day) (n = 6 RCTs, 42738 participants) Evidence A source
Unstable angina hospitalization RR 0.75 (0.66 to 0.87); no significant effect on cardiovascular death or ischemic stroke; formulation modified benefit
The Cochrane review found very few differences in children's cognition, IQ, vision or behavior after their mothers took omega-3 in pregnancy, mostly on low-quality evidence. — children of women in RCTs of antenatal omega-3 LCPUFA vs no omega-3 Evidence A source
Very few differences in cognition, IQ, vision, neurodevelopment, growth, language, behavior; mostly low to very low-quality evidence
A 2021 meta-analysis of 37 placebo-controlled trials found an 11% drop in preterm birth that disappeared in sensitivity analyses. — pregnant women in 37 RCTs of omega-3 supplements vs placebo, searched to June 2020 (n = 37 trials) Evidence A source
Preterm RR 0.89 (95% CI 0.82 to 0.97), early preterm RR 0.73 (0.58 to 0.92); after sensitivity analyses RR 0.92 (0.83 to 1.01) and 0.82 (0.61 to 1.09)
In the largest trial, ORIP (5486 pregnancies in Australia), 900 mg/day of omega-3 from fish oil did not reduce early preterm birth. — women pregnant with single or multiple fetuses at six Australian centers, fish oil 900 mg n-3 LCPUFA daily from before 20 weeks to 34 weeks vs vegetable oil (n = 5486) Evidence B source
Early preterm <34 wk 2.2% vs 2.0%, adjusted RR 1.13 (95% CI 0.79 to 1.63)
A 2012 Cochrane review of 11 trials (596 people) found only two small fish oil trials in eczema and judged the evidence for dietary supplements unconvincing. — people with established atopic eczema in RCTs of dietary supplements; 2 trials of fish oil vs olive or corn oil (n = 596) Evidence A source
Possible modest benefit in two small fish oil trials; no convincing evidence overall
Observational data pooled in a 2014 meta-analysis of 5 studies did not link omega-3 intake with basal cell skin cancer (OR 1.05). — two case-control and three cohort studies of dietary n-3 PUFA and skin cancer (n = 5 studies) Evidence C source
BCC pooled OR 1.05 (0.86-1.28); SCC OR 0.86 (0.59-1.23); melanoma OR 0.52 from one estimate
NCCIH reports that reviews disagree on psoriasis, and that a 2019 meta-analysis of 13 trials found no significant drop in severity. — people with psoriasis (n = 13 trials, 625 participants (cited review)) Evidence E source
Conflicting reviews; most recent meta-analysis null
In the STRENGTH trial of 13,078 statin users with high triglycerides, 4 g a day of EPA plus DHA did not reduce heart attacks, strokes or heart deaths versus corn oil. — statin-treated patients at high cardiovascular risk with hypertriglyceridemia and low HDL-C, median TG 240 mg/dL (n = 13078) Evidence B source
Primary MACE 12.0% vs 12.2%, HR 0.99 (95% CI 0.90 to 1.09); trial stopped early for futility; GI adverse events 24.7% vs 14.7%
An earlier meta-analysis that pooled fish and fish oil trials found participants taking fish or fish oil lost 1.3 lb (0.59 kg) more body weight than controls. — participants in randomized controlled trials of fish or fish oil intake Evidence A source
Body weight -1.3 lb (95% CI -2.1 to -0.46; metric: -0.59 kg, -0.96 to -0.21)
A meta-analysis of 15 controlled trials with 1,504 people found omega-3 did not change overall appetite and modestly raised the desire to eat. — participants in controlled clinical trials of n-3 PUFA supplementation vs control (n = 1,504) Evidence A source
Overall appetite SMD 0.458 (95% CI -0.327 to 1.242, P = 0.25); desire to eat SMD 1.07 (0.116 to 2.029, P = 0.02)
EFSA found too little data to set an upper limit for EPA and DHA in 2012. It concluded that supplements of EPA and DHA up to 5 g a day combined, or EPA alone up to 1.8 g, raise no safety concerns for adults. About 5 g a day did not appear to raise the risk of spontaneous bleeding. — EU population groups, adults and general population Evidence E source
No UL could be set; EPA+DHA up to 5 g/day and EPA alone up to 1.8 g/day raise no safety concerns for adults; DHA alone up to about 1 g/day none for the general population; up to about 5 g/day no rise in spontaneous bleeding

The bottom line

Krill oil sold as a better fish oil is no better for blood lipids. A network meta-analysis of 64 trials found no significant difference between the two, with each gram of omega-3 lowering triglycerides by about 9 mg/dL from either source, in an indirect comparison. For people who do not eat fish, algal oil is a real alternative. In a placebo-controlled trial in 74 adults over 14 weeks, its DHA and EPA reached the blood no worse than fish oil did, in a non-inferiority test. The EU has refused the claim that fish oil thins the blood. Laboratory reviews note that its omega-3 fats oxidize easily, which is why food makers encapsulate it. The real caution is heart rhythm. Across 7 large trials with 81,210 people, mean age 65, marine omega-3 supplements raised the risk of atrial fibrillation by 25% (HR 1.25, 1.07 to 1.46), and by 49% in trials above 1 g a day. In those trials the arrhythmia was often logged as a side effect instead of a planned outcome. A newer meta-analysis of 35 trials, including unpublished data, found the extra risk only in people at high cardiovascular risk taking more than 1,500 mg EPA and DHA a day, an absolute increase of 0.8%. On bleeding, a meta-analysis of 11 trials with 120,643 patients found no overall rise (RR 1.09, 0.91 to 1.31), but high-dose purified EPA raised bleeding by 50% in relative terms, 0.6% in absolute terms. In REDUCE-IT, on 4 g a day of purified EPA, serious bleeding was 2.7% against 2.1%. VITAL, at 1 g a day, saw no excess bleeding. In a small single-surgeon series of 95 spinal operations, the 16 people who stopped omega-3 about 2 days before surgery lost no more blood (138 against 5.2 fl oz (154 mL), P = 0.53). With warfarin, NIH notes that fish oil might prolong clotting times. Most research finds 3 to 6 g a day does not significantly change anticoagulation, and labels of omega-3 drugs advise periodic INR checks, so anyone on a blood thinner should raise fish oil with the prescriber. In pregnancy, a Cochrane review found omega-3 supplements lowered preterm birth before 37 weeks by 11% across 26 trials with 10,304 women, on high-quality evidence. Early preterm birth before 34 weeks fell by 42% across 9 trials with 5,204 women, while pregnancies running past 42 weeks became more common (RR 1.61, 1.11 to 2.33). In ORIP, the largest single trial, 900 mg a day did not reduce early preterm birth and very large babies for gestational age became 30% more common. Those trials used fish oil, not cod liver oil. NIH warns that preformed vitamin A above the upper limit can cause birth defects of the eye, skull, lungs and heart, which is why the 3,000 mcg supplement ceiling in pregnancy matters for liver oils. A teaspoon of cod liver oil, about 4.5 g, carries about 1,350 mcg of it.

Questions about fish oil, answered from the trials

Related foods

Fish: the omega-3 and the mercury arrive together

Guides that discuss this food

Omega-3: a small heart benefit with a heart rhythm cost

Sources

hf2-fsho-6 · agency advice
Cod liver oil supplements provide vitamin A and vitamin D in addition to LC omega-3s.
NIH Office of Dietary Supplements, Omega-3 Fatty Acids Fact Sheet for Health Professionals · checked 2026-10-08
hf2-fsho-7 · food composition dataset
Fish oil, cod liver (FDC 173577, sr_legacy): Vitamin A, RAE 30000 ug; Retinol 30000 ug; Vitamin D (D2 + D3) 250 ug; Energy 902 kcal per 100 g | tsp 4.5 g | tbsp 13.6 g | cup 218 g
USDA FoodData Central, SR Legacy, FDC 173577 · checked 2026-10-08
fshoil-r6-07 · network meta-analysis of RCTs
However, the net differences in triglycerides (WMD -4.07 [95%CI, -15.22 to 7.08]), low-density lipoprotein cholesterol (WMD 3.01 [95%CI, -5.49 to 11.51]), high-density lipoprotein cholesterol (WMD 1.37 [95%CI, -3.73 to 6.48]), and total cholesterol (WMD 1.69 [95%CI, -6.62 to 10.01]) were not significantly different between the krill oil and fish oil groups. One gram of n-3 fatty acids contained in fish oil and krill oil lowered median triglycerides by 8.971 mg/dL (95% credible interval [CrI], 2.27 to 14.04) and 9.838 mg/dL (95%CrI, 0.72 to 19.40), respectively.
Nutr Rev, 2020 · checked 2026-10-03
fshoil-r6-09 · RCT
This was a double-blind, parallel-design, single-center, 128-day study with sixty young, healthy subjects randomized into two groups. ... RESULTS: For erythrocyte PLFA profiles, EPA, docosapentaenoic acid (DPA) and DHA percentage of total erythrocyte PLFA were significantly greater for the Ultimate Omega® group than for the MEG-3 group, at week 16 (P < 0.05)
PLoS One, 2023 · checked 2026-10-03
fshoil-r6-10 · RCT (equivalence)
We analyzed the plasma phospholipid levels of 74 adult men and women after 6 and 14 weeks of consuming omega-3 supplements derived from either microalgal or fish oil in a randomized double-blind placebo-controlled parallel-group clinical trial. We found that the bioavailability of DHA and EPA in plasma phospholipids from microalgal oil supplements are statistically non-inferior compared to fish oil supplements
Int J Mol Sci, 2025 · checked 2026-10-03
fshoil-r6-13 · meta-analysis (lab)
However, PUFAs are prone to oxidation and have a poor water solubility which limits the use of fish oils into food formulations. ... The three most frequent methods applied for fish oil encapsulation were spray drying (42.86%), freeze drying (21.43%), and electrohydrodynamic (19.04%) methods, respectively.
Crit Rev Food Sci Nutr, 2022 · checked 2026-10-03
ev-fobp-01 · meta-analysis of randomized controlled trials
The optimal intake in both systolic BP and diastolic BP reductions (mm Hg) were obtained by moderate doses between 2 g/d (systolic BP, -2.61 [95% CI, -3.57 to -1.65]; diastolic BP, -1.64 [95% CI, -2.29 to -0.99]) and 3 g/d (systolic BP, -2.61 [95% CI, -3.52 to -1.69]; diastolic BP, -1.80 [95% CI, -2.38 to -1.23]).
J Am Heart Assoc, 2022 · checked 2026-10-07
ev-fobp-04 · meta-analysis of randomized controlled trials
Compared with placebo, EPA+DHA provision reduced systolic blood pressure (-1.52 mm Hg; 95% confidence interval (CI) = -2.25 to -0.79) and diastolic blood pressure (-0.99 mm Hg; 95% CI = -1.54 to -0.44) in the meta-analyses of all studies combined.
Am J Hypertens, 2014 · checked 2026-10-07
ev-fobp-08 · randomized controlled trial
Furthermore, eating the enriched foods resulted in clinically relevant reductions in diastolic blood pressure (- 3.1 mmHg [- 5.8, - 0.3]).
Sci Rep, 2020 · checked 2026-10-07
ev-fodep-01 · meta-analysis
For the placebo comparison, n-3PUFA supplementation resulted in a small to modest benefit for depressive symptomology, compared to placebo: standardised mean difference (SMD) (random-effects model) -0.40 (95% confidence interval (CI) -0.64 to -0.16; 33 studies, 1848 participants; very low-certainty evidence), but this effect is unlikely to be clinically meaningful.
Cochrane Database Syst Rev, 2021 · checked 2026-10-07
ev-fodep-03 · meta-analysis
There was no evidence for a difference between n-3PUFA and placebo groups in remission rates (OR 1.13, 95% CI 0.74 to 1.72; 8 studies, 609 participants, low-certainty evidence), response rates (OR 1.20, 95% CI 0.80 to 1.79; 17 studies, 794 participants; low-certainty evidence), quality of life (SMD -0.38 (95% CI -0.82 to 0.06), 12 studies, 476 participants, very low-certainty evidence), or trial non-completion (OR 0.92, 95% CI 0.70 to 1.22; 29 studies, 1777 participants, very low-certainty evidence).
Cochrane Database Syst Rev, 2021 · checked 2026-10-07
ev-fodep-04 · meta-analysis
Compared with placebo, EPA-pure (=100% EPA) and EPA-major formulations (≥60% EPA) demonstrated clinical benefits with an EPA dosage ≤1 g/d (SMD = -0.50, P = 0.003, and SMD = -1.03, P = 0.03, respectively), whereas DHA-pure and DHA-major formulations did not exhibit such benefits.
Transl Psychiatry, 2019 · checked 2026-10-07
ev-fodep-05 · meta-analysis
Meta-analysis suggested that increasing long-chain omega-3 probably has little or no effect on risk of depression symptoms (risk ratio 1.01, 95% CI 0.92-1.10, I2 = 0%, median dose 0.95 g/d, duration 12 months) or anxiety symptoms (standardised mean difference 0.15, 95% CI 0.05-0.26, I2 = 0%, median dose 1.1 g/d, duration 6 months; both moderate-quality evidence).
Br J Psychiatry, 2021 · checked 2026-10-07
ev-fodep-14 · meta-analysis
The non-linear dose-response analysis indicated the greatest improvement at 2 g/d (SMD: -0.93, 95%CI: -1.85, -0.01), and that supplementation in a dose lower than 2 g/d did not affect anxiety symptoms.
BMC Psychiatry, 2024 · checked 2026-10-07
ev-fohd-01 · Cochrane systematic review
Meta-analysis and sensitivity analyses suggested little or no effect of increasing LCn3 on all-cause mortality (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.93 to 1.01; 143,693 participants; 11,297 deaths in 45 RCTs; high-certainty evidence), cardiovascular mortality (RR 0.92, 95% CI 0.86 to 0.99; 117,837 participants; 5658 deaths in 29 RCTs; moderate-certainty evidence), cardiovascular events (RR 0.96, 95% CI 0.92 to 1.01; 140,482 participants; 17,619 people experienced events in 43 RCTs; high-certainty evidence)
Cochrane Database Syst Rev, 2020 · checked 2026-10-07
ev-fohd-02 · Cochrane systematic review
Increasing LCn3 may slightly reduce coronary heart disease mortality (number needed to treat for an additional beneficial outcome (NNTB) 334, RR 0.90, 95% CI 0.81 to 1.00; 127,378 participants; 3598 coronary heart disease deaths in 24 RCTs, low-certainty evidence) and coronary heart disease events (NNTB 167, RR 0.91, 95% CI 0.85 to 0.97; 134,116 participants; 8791 people experienced coronary heart disease events in 32 RCTs, low-certainty evidence).
Cochrane Database Syst Rev, 2020 · checked 2026-10-07
ev-fohd-04 · meta-analysis of randomized controlled trials
In the analysis excluding REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial), marine omega-3 supplementation was associated with significantly lower risk of myocardial infarction (rate ratio [RR] [95% CI]: 0.92 [0.86, 0.99]; P=0.020), CHD death (RR [95% CI]: 0.92 [0.86, 0.98]; P=0.014), total CHD (RR [95% CI]: 0.95 [0.91, 0.99]; P=0.008), CVD death (RR [95% CI]: 0.93 [0.88, 0.99]; P=0.013), and total CVD (RR [95% CI]: 0.97 [0.94, 0.99]; P=0.015).
J Am Heart Assoc, 2019 · checked 2026-10-07
ev-fohd-05 · meta-analysis of randomized controlled trials
Supplementation was associated with reduced risk of MI (relative risk [RR], 0.87; 95% CI, 0.80 to 0.96), high certainty number needed to treat (NNT) of 272; CHD events (RR, 0.90; 95% CI, 0.84 to 0.97), high certainty NNT of 192; fatal MI (RR, 0.65; 95% CI, 0.46 to 0.91]), moderate certainty NNT = 128; and CHD mortality (RR, 0.91; 95% CI, 0.85 to 0.98), low certainty NNT = 431, but not CVD events (RR, 0.95; 95% CI, 0.90 to 1.00). The effect is dose dependent for CVD events and MI.
Mayo Clin Proc, 2021 · checked 2026-10-07
ev-fohd-07 · meta-analysis of randomized controlled trials
Overall, compared with controls, omega-3 supplementation reduced the risk of revascularization [0.90, 95% confidence interval (CI) 0.84-0.98; P = 0.001; P-heterogeneity = 0.0002; I2 = 68%], MI (0.89, 95% CI 0.81-0.98; P = 0.02; P-heterogeneity = 0.06; I2 = 41%), and cardiovascular death (0.92, 95% CI 0.85-0.99; P = 0.02; P-heterogeneity = 0.13; I2 = 33%).
Eur J Prev Cardiol, 2024 · checked 2026-10-07
ev-foinf-02 · meta-analysis
Pooled results showed that n-3 PUFAs supplementation could significantly relieve the arthritis pain as compared to placebo (standardized mean difference [SMD]: - 0.29, 95% confidence interval [CI] - 0.47 to - 0.11, p = 0.002, I2 = 60%).
J Orthop Surg Res, 2023 · checked 2026-10-07
ev-foinf-05 · meta-analysis
Supplementation with omega-3 PUFAs for 3-4 months reduces patient reported joint pain intensity (SMD: -0.26; 95% CI: -0.49 to -0.03, p=0.03), minutes of morning stiffness (SMD: -0.43; 95% CI: -0.72 to -0.15, p=0.003), number of painful and/or tender joints (SMD: -0.29; 95% CI: -0.48 to -0.10, p=0.003), and NSAID consumption (SMD: -0.40; 95% CI: -0.72 to -0.08, p=0.01).
Pain, 2007 · checked 2026-10-07
ev-foinf-06 · umbrella review
Our findings demonstrated that the n-3 PUFA supplementation significantly reduced serum C-reactive protein (CRP) (ES = -0.40; 95 % CI: -0.56, -0.24, p < 0.001; I2 = 89.5 %, p < 0.001), Tumour necrosis factor α (TNFα) (ES = -0.23; 95 % CI: -0.37, -0.08, p = 0.002; I2 = 60.1 %, p < 0.001), and interleukin 6 (IL-6) concentrations (ES = -0.22; 95 % CI: -0.39, -0.05, p = 0.010; I2 = 66.2 %, p < 0.001).
Int Immunopharmacol, 2022 · checked 2026-10-07
ev-foinf-08 · RCT
The ORs for higher pain prevalence or severity for vitamin D and omega-3 supplementation vs placebo were 0.99 ([CI] 0.94-1.05) and 0.99 ([CI] 0.94-1.04), respectively.
Pain, 2024 · checked 2026-10-07
ev-fopreg-01 · meta-analysis of RCTs
Preterm birth < 37 weeks (13.4% versus 11.9%; risk ratio (RR) 0.89, 95% confidence interval (CI) 0.81 to 0.97; 26 RCTs, 10,304 participants; high-quality evidence) and early preterm birth < 34 weeks (4.6% versus 2.7%; RR 0.58, 95% CI 0.44 to 0.77; 9 RCTs, 5204 participants; high-quality evidence) were both lower in women who received omega-3 LCPUFA compared with no omega-3.
Cochrane Database Syst Rev, 2018 · checked 2026-10-07
ev-fopreg-02 · meta-analysis of RCTs
Mean gestational length was greater in women who received omega-3 LCPUFA (mean difference (MD) 1.67 days, 95% CI 0.95 to 2.39; 41 trials, 12,517 participants; moderate-quality evidence), and pre-eclampsia may possibly be reduced with omega-3 LCPUFA (RR 0.84, 95% CI 0.69 to 1.01; 20 trials, 8306 participants; low-quality evidence).
Cochrane Database Syst Rev, 2018 · checked 2026-10-07
ev-fopreg-06 · meta-analysis of RCTs
RESULTS: In 24 comparisons (21,919 women) n-3 fatty acids played a protective role against the risk of preeclampsia (RR = 0.84, 95% CI 0.74-0.96 p = 0.008; I2 = 24%).
Arch Gynecol Obstet, 2023 · checked 2026-10-07
ev-fopreg-11 · RCT
In comparison with placebo, DHA supplementation resulted in higher maternal and cord RBC-phospholipid-DHA (2.6%; P < 0.001), longer gestation duration (2.9 d; P = 0.041), and greater birth weight (172 g; P = 0.004), length (0.7 cm; P = 0.022), and head circumference (0.5 cm; P = 0.012).
Am J Clin Nutr, 2013 · checked 2026-10-07
ev-fopreg-12 · RCT
n-3 LCPUFA compared with control was associated with a 2-d prolongation of pregnancy [median (IQR): 282 (275-288) d compared with 280 (273-286) d, P = 0.02], a 97-g higher birth weight (mean ± SD: 3601 ± 534 g compared with 3504 ± 528 g, P = 0.02), and an increased size for GA according to the Norwegian population-based growth curves-Skjærven (mean ± SD: 49.9 ± 28.3 percentiles compared with 44.5 ± 27.6 percentiles, P = 0.01).
J Nutr, 2019 · checked 2026-10-07
ev-fosk-01 · meta-analysis
Fish oil supplement did not significantly reduce the severity of psoriasis when assessed by Psoriasis Area and Severity Index score (mean difference - 0.28; 95% confidence interval - 1.74 to 1.19).
BMC Complement Altern Med, 2019 · checked 2026-10-07
ev-fosk-06 · meta-analysis
In blind doctor assessments, PSO, capsaicin-isoflavones (CI), saw palmetto extract (ESR), Omega 3&6, Lambdapil, Nutrafol, and Multi-component supplements (AGA-P) showed higher hair regeneration scores than placebo or conventional treatments.
Front Nutr, 2025 · checked 2026-10-07
ev-fosk-08 · RCT
After 10 weeks of omega-3 fatty acid or γ-linoleic acid supplementation, inflammatory and non-inflammatory acne lesions decreased significantly.
Acta Derm Venereol, 2014 · checked 2026-10-07
ev-fosk-10 · RCT
Photoimmunosuppression appeared less in the n-3 PUFA group than in the control group (not statistically significant [mean difference (95% CI): 6.9% (-2.1%, 15.9%)]).
Am J Clin Nutr, 2013 · checked 2026-10-07
ev-fotg-01 · dose-response meta-analysis of randomized controlled trials
The mean change in triglyceride was −42.61 (95% CI, −53.41 to −31.80) mg/dL for 2 g/d and −68.90 (95% CI, −98.40 to −39.40) mg/dL for 3 g/d of DHA + EPA.
J Am Heart Assoc, 2023 · checked 2026-10-07
ev-fotg-04 · Cochrane systematic review
Increasing LCn3 and ALA had little or no effect on serious adverse events, adiposity, lipids and blood pressure, except increasing LCn3 reduced triglycerides by ˜15% in a dose-dependent way (high-certainty evidence).
Cochrane Database Syst Rev, 2020 · checked 2026-10-07
ev-fotg-05 · meta-analysis of randomized controlled trials
The results revealed that the fish oil supplements significantly reduced TG (WMD: - 25.50 mg/dl, 95% CI: - 42.44, - 8.57, P = 0.000) levels compared to corn oil.
Syst Rev, 2024 · checked 2026-10-07
ev-fotg-06 · network meta-analysis of randomized controlled trials
One gram of n-3 fatty acids contained in fish oil and krill oil lowered median triglycerides by 8.971 mg/dL (95% credible interval [CrI], 2.27 to 14.04) and 9.838 mg/dL (95%CrI, 0.72 to 19.40), respectively.
Nutr Rev, 2020 · checked 2026-10-07
ev-fowl-01 · meta-analysis
The calculated results indicated that fish oil was not associated with a body weight reduction (SMD = -0.07, 95% CI -0.21 to 0.07, P = 0.31; Fig 2A) compared with controls.
PLoS One, 2015 · checked 2026-10-07
ev-fowl-02 · meta-analysis
However, waist circumference was significantly reduced (SMD = -0.23, 95% CI -0.40 to -0.06, P = 0.008) in those with fish oil supplementation combined with life modification intervention.
PLoS One, 2015 · checked 2026-10-07
ev-fowl-03 · meta-analysis
Based on the meta-analysis of nine studies, a statistically nonsignificant difference was revealed in weight loss between n-3 PUFA and placebo (p=0.99; weighted mean difference [WMD]: 0.00; 95% confidence interval [CI] -0.42 to 0.43), whereas n-3 PUFA was superior to placebo in reducing serum triglyceride levels (p=0.0007; standard median difference [Std MD]: -0.59; 95% CI -0.93 to -0.25).
J Nutr Health Aging, 2017 · checked 2026-10-07
ev-fowl-05 · randomized controlled trial
No significant differences in weight loss were observed between the omega-3 (-5.2 kg; 95% CI: -6.0, -4.4 kg) and placebo (-5.8 kg; 95% CI: -6.7, -5.1 kg) arms.
Am J Clin Nutr, 2011 · checked 2026-10-07
ev-fowl-06 · randomized controlled trial
However, it would appear that supplementation with LCn-3PUFA had no significant effect on weight loss or weight maintenance over the 14 weeks.
Br J Nutr, 2012 · checked 2026-10-07
ev-fowl-13 · meta-analysis
There was no significant effect of omega-3 and vitamin E co-supplementation on body weight (BW) (WMD=0.14 kg; 95% CI: -0.13 to 0.42; p=0.297), and body mass index (BMI) (WMD=0.08, 95% CI: -0.01 to 0.16, p=0.073).
Int J Vitam Nutr Res, 2023 · checked 2026-10-07
fshoil-r6-01 · meta-analysis of RCTs
Meta-analysis and sensitivity analyses suggested little or no effect of increasing LCn3 on all-cause mortality (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.93 to 1.01; 143,693 participants; 11,297 deaths in 45 RCTs; high-certainty evidence)
Cochrane Database Syst Rev, 2020 · checked 2026-10-03
fshoil-r6-02 · meta-analysis of RCTs
Increasing LCn3 may slightly reduce coronary heart disease mortality (number needed to treat for an additional beneficial outcome (NNTB) 334, RR 0.90, 95% CI 0.81 to 1.00; 127,378 participants; 3598 coronary heart disease deaths in 24 RCTs, low-certainty evidence) and coronary heart disease events (NNTB 167, RR 0.91, 95% CI 0.85 to 0.97; 134,116 participants; 8791 people experienced coronary heart disease events in 32 RCTs, low-certainty evidence).
Cochrane Database Syst Rev, 2020 · checked 2026-10-03
fshoil-r6-08 · meta-analysis of RCTs
Overall, 16 eligible trials were included in this systematic review and meta-analysis. The results revealed that the fish oil supplements significantly reduced TG (WMD: - 25.50 mg/dl, 95% CI: - 42.44, - 8.57, P = 0.000) levels compared to corn oil. Also, in this study, fish oil supplements had a positive and significant effect on HDL (WMD: 2.54 mg/dl, 95% CI: 0.55, 4.52). There were no significant changes in TC and LDL.
Syst Rev, 2024 · checked 2026-10-03
ev-fobp-02 · meta-analysis of randomized controlled trials
In both SBP and DBP models, combined doses >3 g/d were associated with weaker or null changes in BP (Table).
J Am Heart Assoc, 2022 · checked 2026-10-07
ev-fobp-09 · meta-analysis of randomized controlled trials
In analyses stratified by dose, the HR was greater in the trials testing >1 g/d (HR, 1.49 [95% CI, 1.04-2.15]; P=0.042) compared with those testing ≤1 g/d (HR, 1.12 [95% CI, 1.03-1.22]; P=0.024; P for interaction <0.001).
Circulation, 2021 · checked 2026-10-07
ev-fobp-10 · agency guideline
The pooled analysis of these trials77,152 indicated that there was no difference in either systolic (Figure 13) or diastolic (Figure 14) blood pressure between the intervention and control groups.
Agency for Healthcare Research and Quality (US), 2012, Dietary Supplements in Adults Taking Cardiovascular Drugs (Comparative Effectiveness Review No. 51) · checked 2026-10-07
ev-fodep-07 · RCT
Regarding serious and common adverse events, the respective prevalence values in omega-3 vs placebo groups were major cardiovascular events (2.7% vs 2.9%), all-cause mortality (3.3% vs 3.1%), suicide (0.02% vs 0.01%), gastrointestinal bleeding (2.6% vs 2.7%), easy bruising (24.8% vs 25.1%), and stomach upset or pain (35.2% vs 35.1%).
JAMA, 2021 · checked 2026-10-07
ev-fodep-08 · meta-analysis
Although the numbers of individuals experiencing adverse events were similar in intervention and placebo groups (odds ratio (OR) 1.27, 95% CI 0.99 to 1.64; 24 studies, 1503 participants; very low-certainty evidence), the confidence intervals include a small decrease to a modest increase in adverse events with n-3PUFAs.
Cochrane Database Syst Rev, 2021 · checked 2026-10-07
ev-fodep-09 · meta-analysis
A prespecified analysis was performed in patients receiving high-dose purified eicosapentaenoic acid (EPA), which demonstrated a 50% increase in the relative risk of bleeding but only a modest increase in the absolute risk of bleeding (0.6%) when compared with placebo.
J Am Heart Assoc, 2024 · checked 2026-10-07
ev-fodep-10 · meta-analysis
Only studies including patients at high-risk for cardiovascular disease who were treated with high-doses of EPA/DHA (>1500 mg/d) showed a statistically significant increase in AF risk with a pooled odds ratio (OR) of 1.43 (95% CI, 1.14-1.79) and an absolute risk difference of 0.8% (0.40%-1.1%).
Circ Arrhythm Electrophysiol, 2026 · checked 2026-10-07
ev-fohd-12 · randomized controlled trial
A larger percentage of patients in the icosapent ethyl group than in the placebo group were hospitalized for atrial fibrillation or flutter (3.1% vs. 2.1%, P=0.004). Serious bleeding events occurred in 2.7% of the patients in the icosapent ethyl group and in 2.1% in the placebo group (P=0.06).
New England Journal of Medicine, 2019, 380(1):11-22 (REDUCE-IT) · checked 2026-10-07
ev-fohd-13 · randomized controlled trial
The primary end point occurred in 785 patients (12.0%) treated with omega-3 CA vs 795 (12.2%) treated with corn oil (hazard ratio, 0.99 [95% CI, 0.90-1.09]; P = .84). A greater rate of gastrointestinal adverse events was observed in the omega-3 CA group (24.7%) compared with corn oil-treated patients (14.7%).
JAMA, 2020 · checked 2026-10-07
ev-fohd-14 · meta-analysis of randomized controlled trials
In meta-analysis, the use of marine ɷ-3 fatty acid supplements was associated with an increased risk of AF (n=2905; HR, 1.25 [95% CI, 1.07-1.46]; P=0.013). In analyses stratified by dose, the HR was greater in the trials testing >1 g/d (HR, 1.49 [95% CI, 1.04-2.15]; P=0.042) compared with those testing ≤1 g/d (HR, 1.12 [95% CI, 1.03-1.22]; P=0.024; P for interaction <0.001).
Circulation, 2021 · checked 2026-10-07
ev-fohd-15 · meta-analysis of randomized controlled trials
Only studies including patients at high-risk for cardiovascular disease who were treated with high-doses of EPA/DHA (>1500 mg/d) showed a statistically significant increase in AF risk with a pooled odds ratio (OR) of 1.43 (95% CI, 1.14-1.79) and an absolute risk difference of 0.8% (0.40%-1.1%).
Circ Arrhythm Electrophysiol, 2026 · checked 2026-10-07
ev-fohd-16 · meta-analysis of randomized controlled trials
In addition, prescription omega-3 acid ethyl ester has a good safety profile, and prescription EPA ethyl ester has a high risk of bleeding.
Cardiovasc Drugs Ther, 2024 · checked 2026-10-07
ev-fohd-21 · agency safety assessment
It concludes that supplemental intakes of EPA and DHA combined at doses up to 5g a day do not raise safety concerns for adults.
EFSA, 2012, news: EFSA assesses safety of long-chain omega-3 fatty acids (Scientific Opinion EFSA Journal 2012;10(7):2815) · checked 2026-10-07
ev-foinf-10 · meta-analysis
In meta-analysis, the use of marine ɷ-3 fatty acid supplements was associated with an increased risk of AF (n=2905; HR, 1.25 [95% CI, 1.07-1.46]; P=0.013).
Circulation, 2021 · checked 2026-10-07
ev-foinf-11 · RCT
No excess risks of bleeding or other serious adverse events were observed.
N Engl J Med, 2019 · checked 2026-10-07
ev-foinf-12 · agency position
Side effects of omega-3 supplements are usually mild. They include unpleasant taste, bad breath, bad-smelling sweat, headache, and gastrointestinal symptoms such as heartburn, nausea, and diarrhea.
NIH National Center for Complementary and Integrative Health, Omega-3 Supplements: What You Need To Know, last updated November 2024 · checked 2026-10-07
ev-fopreg-03 · meta-analysis of RCTs
Prolonged gestation > 42 weeks was probably increased from 1.6% to 2.6% in women who received omega-3 LCPUFA compared with no omega-3 (RR 1.61 95% CI 1.11 to 2.33; 5141 participants; 6 RCTs; moderate-quality evidence).
Cochrane Database Syst Rev, 2018 · checked 2026-10-07
ev-fopreg-09 · RCT
There were no significant differences between the groups in the incidence of interventions in post-term (>41 weeks of gestation) deliveries, in adverse events, or in other pregnancy or neonatal outcomes, except that a higher percentage of infants born to women in the n-3 group than in the control group were very large for gestational age at birth (adjusted relative risk, 1.30; 95% CI, 1.02 to 1.65).
Makrides M et al., N Engl J Med, 2019 · checked 2026-10-07
ev-fosk-12 · meta-analysis
Compared with the control group, RxOME3FAs were associated with more treatment-related dysgeusia (fishy taste; p = 0.011) and skin abnormalities (eruption, itching, exanthema, or eczema; p < 0.001).
Prostaglandins Leukot Essent Fatty Acids, 2018 · checked 2026-10-07
ev-fosk-13 · agency position
It concludes that supplemental intakes of EPA and DHA combined at doses up to 5g a day do not raise safety concerns for adults.
EFSA, 2012, news: EFSA assesses safety of long-chain omega-3 fatty acids (Scientific Opinion EFSA Journal 2012;10(7):2815) · checked 2026-10-07
ev-fotg-03 · dose-response meta-analysis of randomized controlled trials
The J‐shaped curve for LDL‐C change peaked at 1.75 g/d intake with a moderate LDL‐C increment of 2.91 (95% CI, 0.34−5.47) and HDL‐C increment of 3.48 (95% CI, 1.09−5.86) mg/dL, respectively.
J Am Heart Assoc, 2023 · checked 2026-10-07
ev-fotg-13 · meta-analysis of randomized controlled trials
In meta-analysis, a significant association was noted between n-3 FA treatment and risk of AF (4.0% vs 3.3%; RR 1.24, 95% CI 1.11-1.38, p = 0.0002).
Cardiovasc Drugs Ther, 2021 · checked 2026-10-07
ev-fotg-14 · meta-analysis of randomized controlled trials
There was no difference in the pooled meta-analytic events of bleeding among patients receiving omega-3 PUFAs and those in the control group (rate ratio [RR], 1.09 [95% CI, 0.91-1.31]; P=0.34).
J Am Heart Assoc, 2024 · checked 2026-10-07
ev-fotg-15 · meta-analysis of randomized controlled trials
Compared with the control group, RxOME3FAs were associated with more treatment-related dysgeusia (fishy taste; p = 0.011) and skin abnormalities (eruption, itching, exanthema, or eczema; p < 0.001).
Prostaglandins Leukot Essent Fatty Acids, 2018 · checked 2026-10-07
ev-fotg-18 · agency systematic review
Low grade evidence indicated no difference between omega-3 fatty acids plus statins compared with statins alone in the following measures: HDL-C, LDL-C, achieving LDL-C and HDL-C targets; diastolic blood pressure; C-reactive protein; blood coagulation parameters; and bleeding time.
Agency for Healthcare Research and Quality, 2012, Dietary Supplements in Adults Taking Cardiovascular Drugs (Comparative Effectiveness Review 51) · checked 2026-10-07
ev-fowl-14 · meta-analysis of randomized controlled trials
In meta-analysis, a significant association was noted between n-3 FA treatment and risk of AF (4.0% vs 3.3%; RR 1.24, 95% CI 1.11-1.38, p = 0.0002).
Cardiovasc Drugs Ther, 2021 · checked 2026-10-07
ev-fowl-15 · meta-analysis of randomized controlled trials
There was no difference in the pooled meta-analytic events of bleeding among patients receiving omega-3 PUFAs and those in the control group (rate ratio [RR], 1.09 [95% CI, 0.91-1.31]; P=0.34).
J Am Heart Assoc, 2024 · checked 2026-10-07
fshoil-r6-03 · RCT
A total of 25,871 participants, including 5106 black participants, underwent randomization. During a median follow-up of 5.3 years, a major cardiovascular event occurred in 386 participants in the n-3 group and in 419 in the placebo group (hazard ratio, 0.92; 95% confidence interval [CI], 0.80 to 1.06; P=0.24). ... No excess risks of bleeding or other serious adverse events were observed.
N Engl J Med, 2019 · checked 2026-10-03
fshoil-r6-04 · meta-analysis of RCTs
Among the 81 210 patients from 7 trials, 58 939 (72.6%) were enrolled in trials testing ≤1 g/d and 22 271 (27.4%) in trials testing >1 g/d of ɷ-3 fatty acids. ... In meta-analysis, the use of marine ɷ-3 fatty acid supplements was associated with an increased risk of AF (n=2905; HR, 1.25 [95% CI, 1.07-1.46]; P=0.013). In analyses stratified by dose, the HR was greater in the trials testing >1 g/d (HR, 1.49 [95% CI, 1.04-2.15]; P=0.042)
Circulation, 2021 · checked 2026-10-03
fshoil-r6-05 · meta-analysis of RCTs
A total of 35 randomized controlled trials (37 data sets; n=114 592) were included in this meta-analysis. Only studies including patients at high-risk for cardiovascular disease who were treated with high-doses of EPA/DHA (>1500 mg/d) showed a statistically significant increase in AF risk with a pooled odds ratio (OR) of 1.43 (95% CI, 1.14-1.79) and an absolute risk difference of 0.8% (0.40%-1.1%).
Circ Arrhythm Electrophysiol, 2026 · checked 2026-10-03
fshoil-r6-11 · case-control
Sixteen patients took n-3FA supplements, stopping an average of 2.3 days before surgery. ... Estimated blood loss was higher in the control group but the difference was not significant (154 vs. 138 mL, P=0.53).
J Spinal Disord Tech, 2012 · checked 2026-10-03
hf2-fsho-1 · agency advice
However, according to the European Food Safety Authority, long-term consumption of EPA and DHA supplements at combined doses of up to about 5 g/day appears to be safe ... Similarly, FDA has concluded that dietary supplements providing no more than 5 g/day EPA and DHA are safe when used as recommended.
NIH Office of Dietary Supplements, Omega-3 Fatty Acids Fact Sheet for Health Professionals · checked 2026-10-08
hf2-fsho-3 · agency advice
Fish oil might prolong clotting times, as indicated by an elevated international normalized ratio (INR), when it is taken with warfarin. ... most research indicates that doses of 3–6 g/day fish oil do not significantly affect the anticoagulant status of patients taking warfarin. ... these package inserts also state that patients taking these products with anticoagulants should be monitored periodically for changes in INR.
NIH Office of Dietary Supplements, Omega-3 Fatty Acids Fact Sheet for Health Professionals · checked 2026-10-08
hf2-fsho-4 · meta-analysis
A total of 120 643 patients from 11 randomized clinical trials were included. There was no difference in the pooled meta-analytic events of bleeding among patients receiving omega-3 PUFAs and those in the control group (rate ratio [RR], 1.09 [95% CI, 0.91-1.31]; P=0.34). ... A prespecified analysis was performed in patients receiving high-dose purified eicosapentaenoic acid (EPA), which demonstrated a 50% increase in the relative risk of bleeding but only a modest increase in the absolute risk of bleeding (0.6%) when compared with placebo.
J Am Heart Assoc, 2024 · checked 2026-10-08
hf2-fsho-5 · agency advice
Total intakes of preformed vitamin A that exceed the UL as well as some retinoid medications used as topical therapies (such as isotretinoin, used to treat severe acne, and etretinate, a treatment for severe psoriasis) can cause congenital birth defects [1]. These birth defects can include malformations of the eye, skull, lungs, and heart [14]. Experts advise women who are or might be pregnant and those who are lactating not to take high doses (more than 3,000 mcg RAE [10,000 IU] daily) of vitamin A supplements [1].
NIH Office of Dietary Supplements, Vitamin A Fact Sheet for Health Professionals · checked 2026-10-08
ev-fobp-11 · regulation (FDA qualified health claim)
Consuming EPA and DHA combined may help lower blood pressure in the general population and reduce the risk of hypertension. However, FDA has concluded that the evidence is inconsistent and inconclusive.
US FDA, 2019, FDA Announces New Qualified Health Claims for EPA and DHA Omega-3 Consumption and the Risk of Hypertension and Coronary Heart Disease (constituent update, June 19, 2019) · checked 2026-10-07
ev-fobp-12 · regulatory register entry
POL-HC-8354 Docosahexaenoic acid and Eicosapentaenoic acid (DHA/EPA) DHA and EPA contribute to the maintenance of normal blood pressure Authorised
EU Register on nutrition and health claims, claim POL-HC-8354, snapshot 2026-09-21 · checked 2026-10-07
ev-fodep-15 · meta-analysis
RESULTS: Amongst nutraceuticals with Grade A evidence, positive directionality and varying levels of support (recommended, provisionally recommended, or weakly recommended) was found for adjunctive omega-3 fatty acids (+++), vitamin D (+), adjunctive probiotics (++), adjunctive zinc (++), methylfolate (+), and adjunctive s-adenosyl methionine (SAMe) (+) in the treatment of unipolar depression.
World J Biol Psychiatry, 2022 · checked 2026-10-07
ev-fodep-16 · agency position
Although some studies have had promising results, it's uncertain whether omega-3 fatty acid supplements are helpful for depression.
NIH National Center for Complementary and Integrative Health, Omega-3 Supplements: What You Need To Know, last updated November 2024 · checked 2026-10-07
ev-fodep-17 · agency position
Other reviews have suggested that if omega-3s do have an effect, EPA may be more beneficial than DHA and that omega-3s may best be used in addition to antidepressant medication rather than in place of it.
NIH National Center for Complementary and Integrative Health, Omega-3 Supplements: What You Need To Know, last updated November 2024 · checked 2026-10-07
ev-fohd-17 · professional society advisory
the majority of coauthors concluded that treatment with omega-3 PUFA supplements is reasonable for the secondary prevention of CHD death (Class IIa Recommendation)
Circulation, 2017, 135(15):e867-e884 (Siscovick et al., AHA science advisory) · checked 2026-10-07
ev-fohd-18 · professional society advisory
Overall, the current evidence from RCTs suggests no benefit of omega-3 PUFA supplementation among patients with or at risk for diabetes mellitus to prevent CVD (Treatment is not indicated: Class III: No Benefit Recommendation).
Circulation, 2017, 135(15):e867-e884 (Siscovick et al., AHA science advisory) · checked 2026-10-07
ev-fohd-19 · regulatory statement
Consuming EPA and DHA combined may reduce the risk of CHD (coronary heart disease) by lowering blood pressure. However, FDA has concluded that the evidence is inconsistent and inconclusive.
US FDA, 2019, FDA Announces New Qualified Health Claims for EPA and DHA Omega-3 Consumption and the Risk of Hypertension and Coronary Heart Disease (constituent update, June 19, 2019) · checked 2026-10-07
ev-fohd-20 · EU health claim register entry
POL-HC-6368 Eicosapentaenoic acid and docosahexaenoic acid (EPA/DHA) EPA and DHA contribute to the normal function of the heart Authorised
EU Register on nutrition and health claims, claim POL-HC-6368, snapshot 2026-09-21 · checked 2026-10-07
ev-foinf-13 · agency position
A 2022 review of 30 studies (1,420 participants) found eating foods rich in polyunsaturated fatty acids (PUFAs), especially omega-3s, may improve symptoms such as pain and swollen and tender joints, and might be an appropriate addition to drug therapy for rheumatoid arthritis.
NIH National Center for Complementary and Integrative Health, Omega-3 Supplements: What You Need To Know, last updated November 2024 · checked 2026-10-07
ev-foinf-14 · regulatory decision
POL-HC-7039 EPA and DHA Omega-3 fatty acids Omega-3 EPA and DHA help maintain healthy joints Non-authorised
EU Register on nutrition and health claims, claim POL-HC-7039, snapshot 2026-09-21 · checked 2026-10-07
ev-fopreg-13 · guideline
Women of childbearing age should obtain a supply of at least 250 mg/d of docosahexaenoic+eicosapentaenoic acid from diet or supplements, and in pregnancy an additional intake of ≥100 to 200 mg/d of docosahexaenoic acid.
Cetin I et al., Am J Obstet Gynecol MFM, 2024 · checked 2026-10-07
ev-fopreg-14 · guideline
Thus, they should receive a supply of approximately 600 to 1000 mg/d of docosahexaenoic+eicosapentaenoic acid, or docosahexaenoic acid alone, given that this dosage showed significant reduction of preterm birth and early preterm birth in randomized controlled trials.
Cetin I et al., Am J Obstet Gynecol MFM, 2024 · checked 2026-10-07
ev-fosk-14 · agency position
there is inconsistent to no evidence to recommend the use of fish oils, evening primrose oil, borage oil, multivitamin supplements, zinc, vitamin D, vitamin E, and vitamins B12 and B6 for the treatment of atopic dermatitis
NIH National Center for Complementary and Integrative Health, Skin Conditions and Complementary Health Approaches: What the Science Says (Clinical Digest) · checked 2026-10-07
ev-fotg-11 · professional society advisory
In treatment of very high triglycerides with 4 g/d, EPA+DHA agents reduce triglycerides by ≥30% with concurrent increases in low-density lipoprotein cholesterol, whereas EPA-only did not raise low-density lipoprotein cholesterol in very high triglycerides.
Circulation, 2019, 140(12):e673-e691 (Skulas-Ray et al., AHA science advisory) · checked 2026-10-07
ev-fotg-12 · professional society advisory
We conclude that prescription n-3 FAs (EPA+DHA or EPA-only) at a dose of 4 g/d (>3 g/d total EPA+DHA) are an effective and safe option for reducing triglycerides as monotherapy or as an adjunct to other lipid-lowering agents.
Circulation, 2019, 140(12):e673-e691 (Skulas-Ray et al., AHA science advisory) · checked 2026-10-07
ev-fotg-16 · agency position
It concludes that supplemental intakes of EPA and DHA combined at doses up to 5g a day do not raise safety concerns for adults.
EFSA, 2012, news: EFSA assesses safety of long-chain omega-3 fatty acids (Scientific Opinion EFSA Journal 2012;10(7):2815) · checked 2026-10-07
ev-fotg-17 · EU health claim register entry
POL-HC-8362 Docosahexaenoic acid and Eicosapentaenoic acid (DHA/EPA) DHA and EPA contribute to the maintenance of normal blood triglyceride levels Authorised
EU Register on nutrition and health claims, claim POL-HC-8362, snapshot 2026-09-21 · checked 2026-10-07
ev-fowl-16 · agency position
It concludes that supplemental intakes of EPA and DHA combined at doses up to 5g a day do not raise safety concerns for adults.
EFSA, 2012, news: EFSA assesses safety of long-chain omega-3 fatty acids (Scientific Opinion EFSA Journal 2012;10(7):2815) · checked 2026-10-07
fshoil-r6-12 · regulatory decision
POL-HC-8240 fish oil (EPA, DHA) Contributes to thin the blood Non-authorised
EU Register on nutrition and health claims, claim POL-HC-8240, snapshot 2026-09-21 · checked 2026-10-03
ev-fobp-03 · meta-analysis of randomized controlled trials
Similar findings were also seen when stratified by hypertension status (SBP ≥140 mm Hg, as defined in most included trials), where patients with hypertension showed greater reductions in SBP and DBP, compared with those without hypertension (Table, Figure S3).
J Am Heart Assoc, 2022 · checked 2026-10-07
ev-fobp-05 · meta-analysis of randomized controlled trials
The strongest effects of EPA+DHA were observed among untreated hypertensive subjects (systolic blood pressure = -4.51 mm Hg, 95% CI = -6.12 to -2.83; diastolic blood pressure = -3.05 mm Hg, 95% CI = -4.35 to - 1.74), although blood pressure also was lowered among normotensive subjects (systolic blood pressure = -1.25 mm Hg, 95% CI = -2.05 to -0.46; diastolic blood pressure = -0.62 mm Hg, 95% CI = -1.22 to -0.02).
Am J Hypertens, 2014 · checked 2026-10-07
ev-fobp-06 · meta-analysis of randomized controlled trials
The summary estimate showed that EPA intervention significantly reduced systolic blood pressure (SBP) (-2.6 mmHg; 95%confident interval (CI): -4.6, -0.5 mmHg), especially in subjects with dyslipidemia (-3.8 mmHg; 95%CI: -6.7, -0.8 mmHg). The pooled effect indicated that supplemental DHA exerted a significant reduction in diastolic blood pressure (DBP) in subjects with dyslipidemia (-3.1 mmHg; 95%CI: -5.9, -0.2 mmHg).
Crit Rev Food Sci Nutr, 2019 · checked 2026-10-07
ev-fobp-07 · randomized controlled trial
No significant differences were observed in blood pressure, brain and skin microcirculation parameters among the different groups.
Food Funct, 2026 · checked 2026-10-07
ev-fodep-06 · RCT
Depression risk was significantly higher comparing omega-3 (651 events, 13.9 per 1000 person-years) with placebo (583 events, 12.3 per 1000 person-years; hazard ratio [HR], 1.13; 95% CI, 1.01-1.26; P = .03).
JAMA, 2021 · checked 2026-10-07
ev-fodep-11 · meta-analysis
Omega-3 PUFA supplementation compared to placebo may reduce self-reported depression symptoms, but the evidence is very uncertain (standardized mean difference [SMD] -0.34, 95% confidence interval [CI] -0.85 to 0.17; lower SMD means greater improvement in depression due to omega-3 PUFA; 5 trials, 185 participants; very low-certainty evidence).
Cochrane Database Syst Rev, 2024 · checked 2026-10-07
ev-fodep-12 · meta-analysis
We advise against prescribing omega-3 PUFAs for the treatment or prevention of depressive symptoms during pregnancy, given a lack of effect with low heterogeneity.
J Clin Psychiatry, 2020 · checked 2026-10-07
ev-fodep-13 · meta-analysis
Sub-group analyses supported the use of omega-3 fatty acids (SMD = -0.14, 95% CI = -0.27 to -0.02, p = 0.03) and botanical drug or dietary intervention (SMD = -0.86, 95% CI = -1.58 to -0.13, p = 0.02) among older participants.
Transl Psychiatry, 2025 · checked 2026-10-07
ev-fohd-06 · meta-analysis of randomized controlled trials
Neither did randomization to omega-3 fatty acid supplementation have any significant associations with major vascular events (RR, 0.97; 95% CI, 0.93-1.01; P = .10), overall or in any subgroups, including subgroups composed of persons with prior coronary heart disease, diabetes, lipid levels greater than a given cutoff level, or statin use.
JAMA Cardiol, 2018 · checked 2026-10-07
ev-fohd-09 · randomized controlled trial
During a median follow-up of 5.3 years, a major cardiovascular event occurred in 386 participants in the n-3 group and in 419 in the placebo group (hazard ratio, 0.92; 95% confidence interval [CI], 0.80 to 1.06; P=0.24).
N Engl J Med, 2019 · checked 2026-10-07
ev-fohd-10 · randomized controlled trial
During a mean follow-up of 7.4 years (adherence rate, 76%), a serious vascular event occurred in 689 patients (8.9%) in the fatty acid group and in 712 (9.2%) in the placebo group (rate ratio, 0.97; 95% confidence interval [CI], 0.87 to 1.08; P=0.55).
N Engl J Med, 2018 · checked 2026-10-07
ev-fohd-11 · randomized controlled trial
A primary end-point event occurred in 17.2% of the patients in the icosapent ethyl group, as compared with 22.0% of the patients in the placebo group (hazard ratio, 0.75; 95% confidence interval [CI], 0.68 to 0.83; P<0.001)
New England Journal of Medicine, 2019, 380(1):11-22 (REDUCE-IT) · checked 2026-10-07
ev-foinf-01 · meta-analysis
A significant effect was found in patients with rheumatoid arthritis (22 trials; -0.21; 95% CI, -0.42 to -0.004) and other or mixed diagnoses (3 trials; -0.63; 95% CI, -1.20 to -0.06), but not in osteoarthritis patients (5 trials; -0.17; 95% CI, -0.57-0.24).
Nutrients, 2017 · checked 2026-10-07
ev-foinf-03 · meta-analysis
The benefits were significant for rheumatoid arthritis, migraine, and other mixed chronic pain conditions, but not for osteoarthritis or mastalgia.
Front Med (Lausanne), 2025 · checked 2026-10-07
ev-foinf-04 · meta-analysis
The analysis showed that omega-3 PUFAs clearly reduced nonsteroidal anti-inflammatory drug (NSAID) consumption (SMD -0.518, 95% CI -0.915 to -0.121, p = 0.011) without between-study heterogeneity (I(2) = 0%).
Arch Med Res, 2012 · checked 2026-10-07
ev-foinf-07 · RCT
WOMAC pain did not differ between the active vitamin D group and the vitamin D placebo group or between the active n-3 FA group and the n-3 FA placebo group at any time point during follow-up.
Arthritis Rheumatol, 2020 · checked 2026-10-07
ev-foinf-09 · RCT
In people with symptomatic knee OA, there was no additional benefit of a high-dose fish oil compared with low-dose fish oil.
Ann Rheum Dis, 2016 · checked 2026-10-07
ev-fopreg-07 · meta-analysis of RCTs
Women who received omega-3 had similar rates of PTB at <37 weeks of gestation (34.5% vs 39.8%; RR, 0.81; 95% CI, 0.59-1.12) and PTB at <34 weeks of gestation (12.0% vs 15.4%; RR, 0.62; 95% CI, 0.26-1.46) compared with control subjects.
Am J Obstet Gynecol, 2015 · checked 2026-10-07
ev-fopreg-10 · RCT
Using the Bayesian model, EPTB was reduced by 65%, from 3.45% to 1.2%, using both cut points.
Clin Nutr, 2023 · checked 2026-10-07
ev-fosk-02 · meta-analysis
Fish oil or ω-3 PUFAs combined with conventional treatments, however, resulted in a decreased PASI score (mean difference [MD], -3.92; 95%CI, -6.15 to -1.69; P = 0.0006) and lesion area (MD, -30.00; 95%CI, -33.82 to -26.18; P < 0.0001).
Nutr Rev, 2020 · checked 2026-10-07
ev-fosk-04 · meta-analysis
Pooled data showed no pronounced decline in the incidence of eczema (RR = 1.09, 95% CI = 0.82~1.46, p = 0.54) or IgE-associated eczema (RR = 0.67; 95% CI = 0.29~1.57; p = 0.34).
Int Arch Allergy Immunol, 2023 · checked 2026-10-07
ev-fosk-05 · meta-analysis
There was a clear reduction in medically diagnosed IgE-mediated eczema with n-3 LCPUFA for children 12 to 36 months of age, but not at any other time point for both medically diagnosed IgE mediated and medically diagnosed IgE mediated and/or parental report.
Cochrane Database Syst Rev, 2015 · checked 2026-10-07
ev-fosk-07 · RCT
After 6 months of treatment, photograph assessment demonstrated a superior improvement in the supplemented group (P < 0.001).
J Cosmet Dermatol, 2015 · checked 2026-10-07
ev-fosk-09 · RCT
The fish oil group was noninferior to the placebo group in reducing total acne counts from baseline (between-group mean difference: -6.0; 95% CI: -16.5 to 4.5).
J Am Acad Dermatol, 2026 · checked 2026-10-07
ev-fotg-02 · dose-response meta-analysis of randomized controlled trials
In subgroup studies stratified by prespecified hyperlipidemic status at entry, the approximately linear trend for triglyceride change was found only in the population with hyperlipidemia but not in the population without hyperlipidemia, where the effect stably plateaued at roughly 40 mg/dL.
J Am Heart Assoc, 2023 · checked 2026-10-07
ev-fotg-07 · meta-analysis of randomized controlled trials
Omega-3 significantly reduced triglycerides (MD: -17.53 mg/dL, 95% CI: -30.64 to -4.41; p = 0.009) and LDL-C (MD: -9.43 mg/dL, 95% CI: -14.20 to -4.65; p = 0.0001).
Nutr Metab Cardiovasc Dis, 2026 · checked 2026-10-07
ev-fotg-08 · meta-analysis of randomized controlled trials
The reduction of triglycerides level was -77.55 mg (IC of -121.85 to -33.25) in Omega 3 groups.
Cien Saude Colet, 2017 · checked 2026-10-07
ev-fotg-09 · randomized controlled trial
Triglycerides decreased by an average of 21.8% in the DHA group (p < 0.001) and 18.3% in the DHA + EPA group (p < 0.001).
J Am Coll Nutr, 2006 · checked 2026-10-07
ev-fowl-07 · meta-analysis
However, n-3 PUFA failed to change body weight, body mass index, high-density lipoprotein cholesterol, very low-density lipoprotein cholesterol and hs-CRP in the overall analysis.
J Ovarian Res, 2023 · checked 2026-10-07
ev-fowl-08 · meta-analysis
Compared to control, fish oil supplementation significantly reduced body mass index [BMI, mean difference (MD): -0.96 kg/m2, 95% confidence interval (CI): -1.69 to -0.23, P = 0.01] but did not significantly reduce body weight or waist circumference (P = 0.68 and 0.76).
Front Pediatr, 2021 · checked 2026-10-07
ev-fowl-09 · meta-analysis
However, ɷ-3 PUFA supplementation did not significantly affect weight, BMI-Z score, Fasting blood sugar (FBS), insulin, Total cholesterol (TC), Low-density lipoprotein- cholesterol (LDL-C), and High-density lipoprotein-cholesterol (HDL-C).
Nutrition & Metabolism, 2025 (omega-3 and cardiometabolic risk factors in obese/overweight children and adolescents) · checked 2026-10-07
ev-fowl-10 · network meta-analysis
Among 25 studies assessing body weight, the DHA&EPA supplementation group showed statistically significant improvements compared to the control group (standardized mean difference [SMD] = 1.29, 95% confidence interval [CI]: 0.40-2.16, P < 0.05), with a surface under the cumulative ranking (SUCRA) score of 48, suggesting modest superiority among compared interventions.
Support Care Cancer, 2025 · checked 2026-10-07
ev-fowl-11 · meta-analysis
There is a significant difference in change in weight (mean difference [MD]: 1.22, 95% CI: 1.05-1.38, P < .01) and HRQoL scores (Global Health [MD: 14.40, 95% CI: 9.22-19.59, P < .01] and Physical Functioning [MD: 10.38, 95% CI: 8.50-12.27, P < .01] subscales) favoring the omega-3 fatty acids group.
Integr Cancer Ther, 2024 · checked 2026-10-07
fshoil-r6-06 · meta-analysis of RCTs
Preterm birth < 37 weeks (13.4% versus 11.9%; risk ratio (RR) 0.89, 95% confidence interval (CI) 0.81 to 0.97; 26 RCTs, 10,304 participants; high-quality evidence) and early preterm birth < 34 weeks (4.6% versus 2.7%; RR 0.58, 95% CI 0.44 to 0.77; 9 RCTs, 5204 participants; high-quality evidence) were both lower in women who received omega-3 LCPUFA compared with no omega-3.
Cochrane Database Syst Rev, 2018 · checked 2026-10-03
ev-fodep-02 · meta-analysis
An SMD of 0.40 represents a difference between groups in scores on the HDRS (17-item) of approximately 2.5 points (95% CI 1.0 to 4.0), where the minimal clinically important change score on this scale is 3.0 points.
Cochrane Database Syst Rev, 2021 · checked 2026-10-07
ev-fohd-03 · Cochrane systematic review
Overall, effects did not differ by trial duration or LCn3 dose in pre-planned subgrouping or meta-regression. There is little evidence of effects of eating fish.
Cochrane Database Syst Rev, 2020 · checked 2026-10-07
ev-fohd-08 · meta-analysis of randomized controlled trials
Among blinded, placebo-controlled, cardiovascular outcomes trials, 4 g/day icosapent ethyl is the only formulation independently associated with reduced cardiovascular events.
Am J Cardiovasc Drugs, 2026 · checked 2026-10-07
ev-fopreg-04 · meta-analysis of RCTs
For the child/adult outcomes, very few differences between antenatal omega-3 LCPUFA supplementation and no omega-3 were observed in cognition, IQ, vision, other neurodevelopment and growth outcomes, language and behaviour (mostly low-quality to very low-quality evidence).
Cochrane Database Syst Rev, 2018 · checked 2026-10-07
ev-fopreg-05 · meta-analysis of RCTs
However, after sensitivity analyses, there were no significant differences in PTB and ePTB risk (PTB RR, 0.92; 95% CI, 0.83 to 1.01, ePTB RR, 0.82; 95% CI, 0.61 to 1.09).
Nutrients, 2021 · checked 2026-10-07
ev-fopreg-08 · RCT
Early preterm delivery occurred in the case of 61 of 2734 pregnancies (2.2%) in the n-3 group and 55 of 2752 pregnancies (2.0%) in the control group; the between-group difference was not significant (adjusted relative risk, 1.13; 95% confidence interval [CI], 0.79 to 1.63; P = 0.50).
Makrides M et al., N Engl J Med, 2019 · checked 2026-10-07
ev-fosk-03 · meta-analysis
Two small studies on fish oil suggest a possible modest benefit, but many outcomes were explored.
Cochrane Database Syst Rev, 2012 · checked 2026-10-07
ev-fosk-11 · meta-analysis
Dietary n-3 PUFAs were not associated with BCC (pooled OR 1.05, 95% CIs 0.86-1.28).
Int J Cancer, 2014 · checked 2026-10-07
ev-fosk-15 · agency position
fish oil supplementation did not significantly reduce the severity of psoriasis when assessed by Psoriasis Area and Severity Index score
NIH National Center for Complementary and Integrative Health, Skin Conditions and Complementary Health Approaches: What the Science Says (Clinical Digest) · checked 2026-10-07
ev-fotg-10 · randomized controlled trial
The primary end point occurred in 785 patients (12.0%) treated with omega-3 CA vs 795 (12.2%) treated with corn oil (hazard ratio, 0.99 [95% CI, 0.90-1.09]; P = .84).
JAMA, 2020 · checked 2026-10-07
ev-fowl-04 · meta-analysis
We found evidence that participants taking fish or fish oil lost 0.59 kg more body weight than controls (95% confidence interval [CI]: -0.96 to -0.21).
Obes Rev, 2014 · checked 2026-10-07
ev-fowl-12 · meta-analysis
However, the n-3 PUFA supplementation significantly increased the desire to eat (SMD = 1.07, 95% CI 0.116, 2.029, P = 0.02) compared to control.
Syst Rev, 2024 · checked 2026-10-07
hf2-fsho-2 · EFSA scientific opinion
Available data are insufficient to establish a UL for n-3 LCPUFA (individually or combined) for any population group. ... Long-term supplemental intakes of EPA and DHA combined up to about 5 g/day do not appear to increase the risk of spontaneous bleeding episodes or bleeding complications ... Supplemental intakes of EPA and DHA combined at doses up to 5 g/day, and supplemental intakes of EPA alone up to 1.8 g/day, do not raise safety concerns for adults. ... Supplemental intakes of DHA alone up to about 1 g/day do not raise safety concerns for the general population.
EFSA NDA Panel, Scientific Opinion on the Tolerable Upper Intake Level of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA), EFSA Journal 2012;10(7):2815 · checked 2026-10-08

Review. Reviewed on 2026-10-08 for evidence level, dose and population context, and claims a reader could misread. Bioma Learn has no human medical reviewer at this time, and we say so rather than invent one. Methodology. This is information, not medical advice.