Krill oil: lowers blood fats, about as well as fish oil

Krill oil does what fish oil does to blood fats, at about the same rate per gram of omega-3. In a meta-analysis of 7 randomized trials with 662 people, krill oil lowered LDL cholesterol by 15.5 mg/dL (95% CI 2.6 to 28.4) and triglycerides by 14.0 mg/dL. Doses varied between trials, the groups were small, and none of the trials counted heart attacks or strokes. The premium story falls apart on lipids. A network meta-analysis of 64 trials found no significant difference between krill and fish oil for triglycerides (-4.07 mg/dL, 95% CI -15.22 to 7.08), LDL, HDL or total cholesterol. Each gram of omega-3 lowered median triglycerides by about 9.8 mg/dL from krill oil and 9.0 mg/dL from fish oil. For blood fats, what matters is the omega-3 dose, not the source. That dose has a ceiling. NIH ODS reports that EFSA considers long-term EPA plus DHA supplements up to about 5 g a day safe, and FDA concluded the same for supplements giving no more than 5 g a day. That is 5 g of EPA plus DHA, not 5 g of oil. Krill is a crustacean, and crustacean shellfish is one of the nine major food allergens FDA lists.

How much is actually in it

• In a 6-month trial in older adults, each 1 g krill oil capsule supplied 322 mg long-chain omega-3, including 193 mg EPA and 96 mg DHA, plus 79 mg choline, at 4 capsules a day. — men and women aged 65 years or older; 4 g/day krill oil for 6 months (n = 94) Evidence B source
  Per 1 g capsule: LCn-3 PUFA 322 mg, EPA 193 mg, DHA 96 mg, choline 79 mg; daily dose 4 g krill oil

What your body absorbs

• In a 12-week double-blind RCT in 72 healthy adults taking 1.1 g omega-3 a day, krill oil raised plasma EPA and DHA about 1.5 times more than fish oil. — 72 healthy adults (53 females, 19 males); 1.1 g/d omega-3 FAs for 12 wk (n = 72) Evidence B source
  About 1.5-fold higher delta EPA and delta DHA with krill oil vs fish oil (P = 0.0001 and 0.005); females 1.5-fold greater EPA rise
• In a 12-week RCT in 62 young adults taking about 250-290 mg EPA+DHA a day, krill oil, fish oil and Calanus oil raised the omega-3 index by the same 1 to 1.15 points. — Sixty-two participants (mean age 29.7 years); 12 weeks (n = 62) Evidence B source
  Omega-3 index rise: krill 1.15 +/- 0.65%, fish oil 1.0 +/- 0.53%, Calanus 1.09 +/- 0.55%; comparable

What it does to your health

• In a meta-analysis of 7 RCTs with 662 people, krill oil lowered LDL cholesterol by 15.5 mg/dL and triglycerides by 14.0 mg/dL. — 7 eligible trials (14 treatment arms) with 662 participants (n = 662) Evidence A source
  LDL-C -15.52 mg/dL (95% CI -28.43 to -2.61); TG -14.03 mg/dL (95% CI -21.38 to -6.67)
• In a meta-analysis of 5 RCTs with 700 people with knee pain, krill oil did not reduce pain or stiffness but slightly improved knee function (SMD -0.24). — five trials with 700 patients using krill oil for knee pain (n = 700) Evidence A source
  Physical function SMD -0.24 (95% CI -0.41 to -0.08), I2 0%; no significant difference for pain, stiffness, lipids
• In an 8-week alternate-day fasting RCT in 41 adults with overweight, krill oil kept fat-free mass steady (-0.44 lb / -0.2 kg) while placebo lost 2.6 lb (1.2 kg), with equal weight loss. — 41 participants (25 women and 16 men), age 39 ± 10 years, BMI 31.1; 8-week ADF (n = 41) Evidence B source
  FFM -0.2 +/- 0.9 kg vs -1.2 +/- 2.0 kg; handgrip -0.44 vs -2 lb (-0.2 vs -0.9 kg); weight -10 vs -9.9 lb (-4.6 vs -4.5 kg)

Safety, limits and interactions

• NIH ODS reports that EFSA considers long-term EPA plus DHA supplements up to about 5 g a day safe. FDA concluded that supplements giving no more than 5 g a day of EPA and DHA are safe when used as recommended. — adults taking EPA and DHA supplements Evidence E source
  EFSA: long-term combined EPA+DHA supplements up to about 5 g/day appear safe; FDA: supplements providing no more than 5 g/day EPA+DHA safe when used as recommended
• NIH ODS says doses of 2 to 15 g a day of EPA and/or DHA might increase bleeding time by reducing platelet aggregation. — people taking 2 to 15 g/day EPA and/or DHA Evidence E source
  Bleeding time might increase through reduced platelet aggregation
• A laboratory study detected a protein tentatively identified as tropomyosin, the main crustacean allergen, in commercial krill oil products, while oils from the zooplankton Calanus finmarchicus showed none. — commercial krill oil products and Calanus finmarchicus oils Evidence D source
  A protein tentatively identified as tropomyosin detected in krill oil products, not in Calanus oils; extraction method not optimal
• FDA lists crustacean shellfish among the nine major food allergens in the US, together with milk, eggs, fish, tree nuts, peanuts, wheat, soybeans and sesame. — people with food allergies, United States Evidence E source
  Crustacean shellfish is one of nine major food allergens
• In a 12-week RCT in 120 healthy adults, an Antarctic krill oil extract at 375 or 750 mg a day changed platelet aggregation time versus placebo and was well tolerated. — 120 adults aged 19 to 70 years; 115 completed; twelve weeks (n = 120) Evidence B source
  Significant between-group differences in platelet aggregation (PFA-200 closure) time and ba-PWV; high dose ba-PWV p = 0.006 vs placebo

What people believe that the data does not support

• A network meta-analysis of 64 RCTs found krill oil and fish oil lower blood lipids equally, and each gram of omega-3 from krill oil cut triglycerides by about 9.8 mg/dL. — 64 randomized controlled trials of krill oil or fish oil Evidence A source
  Krill vs fish oil: TG WMD -4.07 (95% CI -15.22 to 7.08), LDL 3.01, HDL 1.37, TC 1.69, all ns; per 1 g n-3 TG -9.838 mg/dL (95% CrI 0.72 to 19.40)
• The EU register lists the claim that krill oil helps improve the comfort of sensitive joints as non-authorized. — EU Register on nutrition and health claims, snapshot 2026-09-21 Evidence E source
  Status Non-authorized

Who this works differently for

• NIH ODS says fish oil might prolong clotting time, seen as a higher INR, in people on warfarin, although most research finds 3 to 6 g a day does not significantly change their anticoagulation. Omega-3 drug labels still advise periodic INR checks with anticoagulants. — patients taking warfarin or other anticoagulants Evidence E source
  Fish oil might raise INR with warfarin; most research finds 3 to 6 g/day fish oil does not significantly affect anticoagulant status; package inserts of omega-3 drugs advise periodic INR monitoring
• Lab data suggest krill tropomyosin may be allergenic. IgE from people with shrimp allergy bound tropomyosin from krill, shrimp, lobster and crab, but not proteins from molluscs or vertebrates. — serum IgE related to shrimp allergy, tested against krill (Euphausia superba, E. pacifica) tropomyosin Evidence D source
  Shrimp-allergy IgE bound krill, shrimp, lobster and crab tropomyosin (about 38 kDa), not mollusc or vertebrate extracts
• In a 12-week pilot RCT in 40 adults over 60 with chronic pain, 4 g krill oil a day raised the omega-3 index from 4.3% to 7.4%, with no serious adverse events. — 40 community-dwelling adults aged ≥60 y with moderate chronic MSK pain; 12 wk (n = 40) Evidence B source
  Omega-3 index 4.3% to 7.4%; fewer pain sites rate ratio 0.59 (95% CI 0.41 to 0.84); no serious adverse events
• Testing of 32 marine supplements found total arsenic above 1000 ng per gram in krill oil products, although arsenic hydrocarbons were not detected in krill oil. — 32 marine-sourced supplements; survey of pregnant women (n = 1997) in the New Hampshire Birth Cohort Study (n = 32) Evidence C source
  Total arsenic >1000 ng/g in seaweed, krill and calanus oil supplements; arsenic hydrocarbons not detected in krill oil
• In a pilot of 16 breastfeeding mothers of NICU infants, krill oil with 250 mg DHA a day for 30 days raised breast-milk DHA by a median of 64%, versus a fall in controls. — Sixteen breastfeeding women, 8 krill oil and 8 control; 30 days (n = 16) Evidence C source
  Delta %DHA median +64.2% vs -7.8% (p 0.025); delta %EPA +39% vs -25.6% (p 0.035)

What is still unknown

• A 2026 network meta-analysis of 23 knee osteoarthritis RCTs ranked krill oil highest on the WOMAC pain subscale, but rated most comparisons low or very low certainty. — Twenty-three RCTs in knee osteoarthritis Evidence A source
  Krill oil SUCRA 0.99 on WOMAC pain subscale; celecoxib ranked highest on VAS pain and WOMAC total; GRADE low to very low
• A systematic review of 70 studies found the evidence on whether krill oil raises omega-3 levels more than fish oil inconclusive. — seventy studies in adult non-pregnant humans (cross-sectional data or baseline data from intervention studies) Evidence C source
  Krill oil v. fish oil: inconclusive

The bottom line

Whether krill omega-3 is absorbed better is unsettled. In 72 healthy adults taking 1.1 g of omega-3 a day for 12 weeks, krill oil raised plasma EPA and DHA about 1.5 times more than fish oil. In 62 young adults taking about 250 to 290 mg a day, krill, fish and Calanus oil raised the red cell omega-3 index by the same 1.0 to 1.15 points, and the krill group got slightly more omega-3. A review of 70 studies called the comparison inconclusive. The trials measured different things at different doses, which is why they do not agree. Capsules differ. In one trial product, each 1 g capsule held 322 mg of long-chain omega-3, with 193 mg EPA and 96 mg DHA, plus 79 mg of choline. Other brands carry less per capsule. For knee pain the evidence leans against. In 5 trials with 700 people, krill oil did not reduce knee pain or stiffness and gave a small gain in knee function (SMD -0.24, 95% CI -0.41 to -0.08). A 2026 network analysis of 23 knee osteoarthritis trials ranked krill oil first on one pain subscale. That is a ranking, not a size of effect, there were no head-to-head trials, and most comparisons were rated low or very low certainty. The EU refused the claim that krill oil improves the comfort of sensitive joints. In an 8-week fasting diet trial in 41 adults with overweight, both groups lost about 9.9 lb (4.5 kg), and the krill group kept its fat-free mass (-0.44 lb / -0.2 kg) while the placebo group lost 2.6 lb (1.2 kg). The trial was small and short. Who should be careful. In a 12-week trial in 120 healthy adults, 375 or 750 mg of a krill oil extract a day changed platelet clotting time against placebo, and the abstract gives no size. NIH ODS says 2 to 15 g a day of EPA and/or DHA might increase bleeding time by reducing platelet aggregation. For fish oil taken with warfarin, ODS says it might raise the INR, 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 with anticoagulants. We found no study of krill oil itself taken with warfarin or other blood thinners, and the 40-person pilot in adults over 60 that reported no serious side effects at 4 g a day excluded people on anticoagulants. If you take one, that gap is a question for your prescriber. Testing of 32 marine supplements found total arsenic above 1000 ng per gram in krill oil products. Inorganic arsenic was detected only in the seaweed products, and arsenic hydrocarbons were not detected in krill oil. On shellfish allergy, the data are from the lab. IgE from people with shrimp allergy bound tropomyosin from krill, shrimp, lobster and crab, and a protein tentatively identified as tropomyosin, the main crustacean allergen, was detected in commercial krill oil products. No amount was reported, and this does not show that a capsule triggers a reaction. We found no study of krill oil taken by people with shellfish allergy. In a pilot of 16 breastfeeding mothers of babies in intensive care, krill oil giving 250 mg DHA a day for 30 days raised breast milk DHA by a median 64%, while it fell in controls. Sixteen women, with no blinding, is a starting point. We found no data on how krill oil oxidizes in storage.

Sources

1. krlo-daily-r3-08 · RCT
   The krill oil group received 4 g/day krill oil (SuperbaBoost™; Aker Biomarine Antarctic AS, Lysaker, Norway). Each 1 g krill oil capsule contained 322 mg LCn-3 PUFA, including 193 mg eicosapentaenoic acid (EPA), 96 mg docosahexaenoic acid (DHA), and 79 mg choline.
   J Nutr Health Aging, 2026 · checked 2026-10-03
2. krlo-daily-r3-05 · RCT
   This double-blind, randomized clinical trial included 72 healthy adults (53 females, 19 males) matched for age and BMI. Participants received 1.1 g/d ω-3 FAs through either krill oil (n = 36) or fish oil (n = 36) for 12 wk. ... Time-by-treatment interactions were significant for plasma delta over baseline concentrations of EPA (P = 0.0001) and DHA (P = 0.005), with krill oil resulting in ∼1.5-fold higher Δ EPA and Δ DHA compared with fish oil.
   Am J Clin Nutr, 2026 · checked 2026-10-03
3. krlo-daily-r3-06 · RCT
   Sixty-two participants (mean ± standard deviation [SD] age: 29.7 ± 8.43 years) completed the randomized parallel group study (CO group: n = 21, 4 capsules/day, EPA + DHA dose: 242 mg/day; FO group: n = 22, 1 capsule/day, EPA + DHA dose: 248 mg/day; KO group: n = 19, 2 capsules/day, EPA + DHA dose: 286 mg/day). ... The post-interventional (mean ± SD) O3I increase was comparable between the three groups (CO: 1.09 ± 0.55%; FO: 1.0 ± 0.53%; KO: 1.15 ± 0.65%, all p < 0.001).
   Lipids, 2023 · checked 2026-10-03
4. krlo-daily-r3-01 · meta-analysis of RCTs
   Meta-analysis of data from 7 eligible trials (14 treatment arms) with 662 participants showed a significant reduction in plasma concentrations of low-density lipoprotein cholesterol (WMD, -15.52 mg/dL; 95%CI, -28.43 to -2.61; P = 0.018) and triglycerides (WMD, -14.03 mg/dL; 95%CI, -21.38 to -6.67; P < 0.001) following supplementation with krill oil.
   Nutr Rev, 2017 · checked 2026-10-03
5. krlo-daily-r3-03 · meta-analysis of RCTs
   We included five trials with 700 patients using krill oil for knee pain. Results showed no significant difference between krill oil and placebo for knee pain, knee stiffness, and lipid profiles. However, krill oil demonstrated a significant small effect in improving knee physical function (SMD -0.24, 95% CI [-0.41; -0.08], I2 = 0%).
   Inflammopharmacology, 2024 · checked 2026-10-03
6. krlo-daily-r3-10 · RCT
   The study was completed by 41 (25 women and 16 men) participants (age: 39 ± 10 years, BMI: 31.1 ± 4.2 kg/m2). Body weight reduction was not different (p > 0.05) between groups (KO, -4.6 ± 1.4 kg; Placebo, -4.5 ± 1.9 kg). The KO group had no change (p > 0.05) in FFM (-0.2 ± 0.9 kg) or HGS (-0.2 ± 0.5 kg). The placebo group experienced a reduction (p < 0.05) in FFM (-1.2 ± 2.0 kg) and HGS (-0.9 ± 0.7 kg).
   Obesity (Silver Spring), 2025 · checked 2026-10-03
7. hf2-krlo-1 · agency fact sheet
   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
8. hf2-krlo-2 · agency fact sheet
   Doses of 2–15 g/day EPA and/or DHA might also increase bleeding time by reducing platelet aggregation.
   NIH Office of Dietary Supplements, Omega-3 Fatty Acids, Fact Sheet for Health Professionals · checked 2026-10-08
9. hf2-krlo-5 · laboratory study
   Tropomyosin is known to be the main allergen in crustaceans and the objective of this study was to investigate if this protein could be detected in commercial crustacean oils from Antarctic krill (Euphausia superba) and the zooplankton Calanus finmarchicus. ... The protein tentatively identified as tropomyosin, was also detected in krill oil products, but not in oils from C. finmarchicus.
   Food Chem, 2013 · checked 2026-10-08
10. hf2-krlo-6 · agency guidance
    The major food allergens are milk, eggs, fish, Crustacean shellfish, tree nuts, peanuts, wheat, soybeans, and sesame.
    Food Allergies, US Food and Drug Administration · checked 2026-10-08
11. krlo-daily-r3-11 · RCT
    A total of 120 adults aged 19 to 70 years were randomized to receive low-dose FJH-KO (375 mg/day), high-dose FJH-KO (750 mg/day), or placebo for twelve weeks. ... FJH-KO supplementation showed significant between-group differences in platelet aggregation time and ba-PWV.
    J Diet Suppl, 2026 · checked 2026-10-03
12. krlo-daily-r3-02 · network meta-analysis
    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
13. krlo-daily-r3-14 · regulatory decision
    POL-HC-8419 Krill oil Helps to improve the comfort of sensitive joints -/- Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-8419, snapshot 2026-09-21 · checked 2026-10-03
14. hf2-krlo-3 · agency fact sheet
    Fish oil might prolong clotting times, as indicated by an elevated international normalized ratio (INR), when it is taken with warfarin, but most research indicates that doses of 3–6 g/day fish oil do not significantly affect the anticoagulant status of patients taking warfarin. ... However, 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
15. hf2-krlo-4 · laboratory study
    Shrimp allergy-related IgE reacted to approximately 38-kDa protein bands in krill (E. superba), shrimp, lobster and crab protein extracts but did not react to protein extracts from either mollusks or vertebrates. ... These observations suggest the potential allergenicity of krill tropomyosin.
    Int Arch Allergy Immunol, 2008 · checked 2026-10-08
16. krlo-daily-r3-09 · RCT (pilot)
    A 12-wk, randomized, double-blind, placebo-controlled pilot trial in 40 community-dwelling adults aged ≥60 y with moderate chronic MSK pain. ... Krill oil supplementation increased the ω-3 index from 4.3% to 7.4%, approaching levels consistent with lower cardiometabolic risk (≥8%), whereas the placebo group showed no meaningful change. ... No serious adverse events occurred.
    J Nutr, 2026 · checked 2026-10-03
17. krlo-daily-r3-12 · product analysis
    A study of 32 marine-sourced supplements found higher total arsenic concentrations (>1000 ng g-1) in supplements made from seaweed, krill and calanus oil, and in fish and fish liver products marketed as "unprocessed". Inorganic arsenic was only detectable in the seaweed samples, and was elevated (8900 ng g-1) in one product. Arsenic hydrocarbons were not detected in krill oil samples
    Chemosphere, 2022 · checked 2026-10-03
18. krlo-daily-r3-13 · pilot trial
    Group 1 received an oral krill oil-based supplement providing 250 mg/day of DHA and 70 mg/day of eicosapentaenoic acid (EPA) for 30 days; group 2 served as control. ... Sixteen breastfeeding women were included. ... Consistently, a significant between-group difference was observed in percentage changes from baseline of DHA (Δ%DHA, group 1: median 64.2% [IQR 27.5;134.6], group 2: -7.8% [-12.1;-3.13], p 0.025)
    Front Pediatr, 2018 · checked 2026-10-03
19. krlo-daily-r3-04 · network meta-analysis
    Probiotics (0.66) and metformin (0.63) showed potential efficacy, but the final network certainty for most of these auxiliary comparisons was low or very low, mainly due to severe imprecision and the absence of direct head-to-head trials. ... On WOMAC subscales, celecoxib was associated with the largest improvements in pain and physical function; krill oil ranked highest on the pain subscale (SUCRA = 0.99), while probiotics and metformin had the most favorable safety profiles (SUCRA = 0.885 and 0.724, respectively).
    Front Med (Lausanne), 2026 · checked 2026-10-03
20. krlo-daily-r3-07 · systematic review
    The search revealed 5076 unique articles of which seventy were included in the qualitative synthesis. ... The evidence for girth, physical activity and krill oil v. fish oil associated with n-3 LCPUFA levels is inconclusive.
    Br J Nutr, 2019 · checked 2026-10-03