Ginger tea: the evidence is for capsules, the cup is untested

Nearly all the solid ginger evidence comes from capsules and powders, and we found no study measuring how much of the active compounds ends up in a home-brewed cup. The strongest result is for nausea in pregnancy. In a meta-analysis of 13 randomized trials with 1174 pregnant women, ginger supplements improved overall nausea and vomiting symptoms against placebo (OR 7.5, 95% CI 4.1 to 13.5) and eased nausea severity. They did not significantly reduce vomiting, and against vitamin B6 the difference was not significant (OR 1.24, 95% CI 0.50 to 3.10). An umbrella review of 18 systematic reviews, mostly of low methodological quality, found capsule doses of 450 to 1950 mg a day did not raise miscarriage or side effects against placebo or B6. Chemotherapy nausea is less clear. In a meta-analysis of 23 trials, a subgroup taking up to 1 g a day for more than four days had less acute vomiting (OR 0.30, 95% CI 0.12 to 0.79), and that is a subgroup result, not the main one. One review did look at ginger tea itself during chemotherapy and reported a very large effect on nausea severity, with very low certainty and no pooled number in the abstract. A plain 240 g cup has about 2 calories.

As people eat it, per 3.5 oz (100 g)

How much is actually in it

• The US survey records plain ginger tea at about 1 calories per 3.5 oz (100 g), so a 240 g cup carries about 2 calories. — USDA FNDDS Tea, ginger, code 92306850, fdc 2710507 (n = 1 record) Evidence E source
  1 calories per 3.5 oz (100 g); 1 cup 240 g = 2.4 calories; 1 small 360 g = 3.6 calories

What it does to your health

• In a crossover RCT of 10 overweight men, 2 g of ginger powder in a hot water drink with breakfast raised the thermic effect of food by about 43 calories a day versus hot water alone. — overweight men, age 39.1 +/- 3.3 y, BMI 27.2 +/- 0.3 kg/m2 (n = 10) Evidence B source
  Thermic effect of food +42.7 +/- 21.4 calories/d (P = 0.049); area under the curve not different (P = 0.43); total post-prandial energy expenditure not changed
• In the same 10-man crossover trial, hunger and expected food intake ratings were lower after the hot ginger drink than after hot water. — overweight men, age 39.1 +/- 3.3 y, BMI 27.2 +/- 0.3 kg/m2 (n = 10) Evidence B source
  Lower hunger AUC (P = 0.002) and prospective food intake AUC (P = 0.004); fullness trend (P = 0.064); actual food intake not measured
• A 2024 meta-analysis of 27 RCTs with 1309 adults found ginger supplements lowered body weight by about 3.3 lb (1.5 kg), with low certainty of evidence. — adults in RCTs of ginger supplementation, mostly capsules or powder (n = 1309) Evidence A source
  Body weight WMD -3.4 lb (95% CI -5.2 to -1.5; metric: -1.52 kg, -2.37 to -0.66); BMI WMD -0.58 kg/m2 (-0.87 to -0.30); GRADE low for weight
• A systematic review of 21 studies on chemotherapy nausea found a large effect of drinking ginger tea on overall nausea severity, but with very low certainty. — adults receiving chemotherapy, 21 interventional and observational studies (n = 21 studies) Evidence C source
  Very large positive effect of ginger tea on overall CINV severity, GRADE very low
• In a meta-analysis of 23 RCTs in chemotherapy, a subgroup taking up to 1 g of ginger a day for over four days had less acute vomiting (OR 0.30). — patients receiving chemotherapy, 23 RCTs (n = 23 RCTs) Evidence A source
  Acute vomiting OR 0.30 (95% CI 0.12 to 0.79) at 1 g/day or less for more than 4 days; nausea incidence not different
• In an RCT on 24 non-diabetic adults, drinking 3.4 fl oz (100 mL) of ginger extract (0.2 g per 3.4 fl oz (100 mL)) after a glucose load lowered the blood glucose rise over 2 hours. — 24 non-diabetic adults aged 18-40, 12 per group, single OGTT (n = 24) Evidence B source
  Glucose iAUC and peak glucose significantly lower (p<0.001) vs control

Safety, limits and interactions

• NCCIH notes that ginger taken by mouth can cause abdominal discomfort, heartburn and diarrhea. — people taking ginger by mouth Evidence E source
  Possible abdominal discomfort, heartburn, diarrhea, mouth and throat irritation
• A review of 149 reports on warfarin lists ginger among foods and herbs that raise bleeding risk with the drug. — 149 articles on 78 foods, herbs and supplements taken with warfarin (n = 149 articles) Evidence C source
  Not quantified for ginger
• In a pooled analysis of placebo-controlled trials in osteoarthritis, ginger modestly cut pain (SMD -0.30, 5 trials, 593 people) but raised the chance of a mild side effect by 12 points. — adults with osteoarthritis in RCTs, capsules 250-1000 mg/d for 3-12 weeks (n = 593) Evidence A source
  Pain SMD -0.30 (95% CI -0.50 to -0.09); adverse events risk difference 0.12 (95% CI 0.02 to 0.23), mainly gastrointestinal

What people believe that the data does not support

• A 2014 survey of 169 UK sugary fizzy drinks found ginger beer had the most sugar, 38.5 g per 330 mL on average. — 169 carbonated sugar-sweetened beverages in 9 UK supermarkets, 2014 (n = 169 products) Evidence C source
  Ginger beer 38.5 +/- 9.9 g sugars per 330 mL; ginger ale 22.9 +/- 7.7 g
• NCCIH advises people taking any medicine to talk with a clinician before using ginger, because some herbs and medicines interact. — people taking medicines Evidence E source
  Check with a health care provider before use
• In a crossover RCT on 10 overweight men a hot drink with 2 g ginger powder raised the thermic effect of a breakfast by about 43 calories a day, while the area under the curve did not differ. — 10 overweight men, BMI about 27, single breakfast test (n = 10) Evidence B source
  Thermic effect of food +42.7 ± 21.4 calories/d (P=.049); area under the curve not different (P=.43); lower hunger (P=.002); no effect on glucose, insulin, lipids
• In an 8-week RCT on 204 people with type 2 diabetes, 3 g of ginger a day taken with three glasses of black tea did not change blood pressure or body measures more than tea alone. — 204 patients with type 2 diabetes, 5 arms, 8 weeks (n = 204) Evidence B source
  No significant between-group differences in BP, sICAM-1 or anthropometrics; within-group SBP change about 1 mmHg

Who this works differently for

• In a 12-week double-blind RCT of 80 obese women, 2 g a day of ginger powder in tablets gave a slight but significant drop in body measures versus placebo, larger in some genotypes. — obese women aged 18 to 45 years (n = 80) Evidence B source
  Slight significant decrease in all anthropometric measures and appetite score; body composition and energy intake not different
• Among 171 warfarin users who kept a 16-week diary, ginger was one of the products linked with more self-reported bleeding. — 171 adults on warfarin anticoagulation, Canadian hospital, 16-week diary (n = 171) Evidence C source
  Ginger use associated with increased risk of self-reported bleeding
• In a meta-analysis of 13 RCTs (n=1174) in pregnancy, ginger improved nausea and vomiting symptoms versus placebo (OR 7.5) but did not beat vitamin B6. — pregnant women with nausea and vomiting, 13 RCTs (n = 1174) Evidence A source
  General NVP symptoms OR 7.475 (95% CI 4.133 to 13.520) vs placebo; vs vitamin B6 OR 1.239 (95% CI 0.495 to 3.102)
• An umbrella review of 18 systematic reviews found ginger supplements of 450 to 1950 mg a day eased pregnancy nausea without raising miscarriage or side effects versus placebo or vitamin B6. — pregnant women, 18 systematic reviews (8 with meta-analysis) (n = 18 reviews) Evidence A source
  Reduced severity and occurrence of nausea and vomiting vs placebo; no excess adverse effects
• In a meta-analysis of 13 RCTs in type 2 diabetes ginger lowered fasting glucose by 16 mg/dL and HbA1c by 0.41 points, with high heterogeneity between trials. — patients with type 2 diabetes, 13 placebo-controlled RCTs (n = 13 trials) Evidence A source
  FBS -16.27 mg/dL (95% CI -25.75 to -6.80); HbA1c -0.41% (95% CI -0.63 to -0.20)
• In a Danish cohort of 225 pregnant women, 11.1% took ginger supplements, mainly as a health boost. — 225 pregnant women at gestational weeks 10-16, Denmark (n = 225) Evidence C source
  Ginger supplement use 11.1%; any alternative medicine 22.7%
• According to NIH NCCIH, ginger taken by mouth can cause heartburn, diarrhea and stomach discomfort, supplements may be safe in pregnancy, and people on medicines should ask a clinician first. — general public Evidence E source
  Side effects listed; pregnancy use may be safe; possible herb-drug interactions

What is still unknown

• The hot ginger drink in that trial was 2 g of dried ginger powder dissolved in hot water, so its dose is known, unlike a home-brewed cup of tea. — overweight men in a crossover trial (n = 10) Evidence B source
  Dose 2 g dried ginger powder in hot water once, with a 525 calories breakfast
• In a crossover RCT of 22 young men, a meal with 20 g of ginger did not change thermogenesis, appetite, food intake or energy balance versus an unspiced meal. — young normal-weight males, age 24.9 y, BMI 21.8 kg/m2 (n = 22) Evidence B source
  No significant effect on diet-induced thermogenesis; appetite P > 0.85, ad libitum energy intake P = 0.63, energy balance P = 0.67 across spices
• A 2025 meta-analysis of 36 RCTs concluded that ginger supplements do not seem to improve body weight or BMI. — adults in RCTs of ginger supplementation (n = 36 trials) Evidence A source
  Body weight and BMI not changed; waist WMD -0.26 in (95% CI -0.42 to -0.09; metric: -0.65 cm, -1.07 to -0.24); body fat WMD -1.49% (-2.65 to -0.32)
• In a meta-analysis of 12 RCTs ginger supplements lowered systolic blood pressure by 5 mmHg and diastolic by 2 mmHg, with low certainty. — adults in 12 RCTs, larger effects at 2000 mg/day or more (n = 12 RCTs) Evidence A source
  SBP -5.03 mmHg (95% CI -8.49 to -1.57); DBP -2.03 mmHg (95% CI -3.90 to -0.15); GRADE low

The bottom line

Ginger tea is often sold as a weight loss drink. In a crossover pilot on 10 overweight men, 2 g of ginger powder in a hot drink raised the thermic effect of breakfast by about 43 calories a day (P=.049), but the area under the energy expenditure curve over 6 hours did not differ (P=.43). That was a single meal, and weight was never measured. In an 8 week trial on 204 people with type 2 diabetes, about 40 per arm, 3 g of ginger a day with three glasses of black tea changed neither blood pressure nor body measures more than the tea alone. Blood sugar and blood pressure results come mostly from supplements. In 24 adults without diabetes, 3.4 fl oz (100 mL) of ginger extract made at 0.2 g per 3.4 fl oz (100 mL), drunk after a glucose load, lowered the 2 hour glucose rise and the peak (p<0.001) in a single test, and the abstract gives no effect size. A meta-analysis of 13 trials in type 2 diabetes found fasting glucose 16 mg/dL lower (95% CI -25.8 to -6.8) and HbA1c 0.41 points lower (95% CI -0.63 to -0.20), with high heterogeneity between trials. Across 12 trials, ginger supplements lowered systolic pressure by 5 mmHg (95% CI -8.5 to -1.6) and diastolic by 2 mmHg (95% CI -3.9 to -0.2), and the certainty is low because the trials were short and varied. In 5 trials on 593 adults with osteoarthritis, capsules of 250 to 1000 mg a day for 3 to 12 weeks cut pain modestly (SMD -0.30, 95% CI -0.50 to -0.09). Who should be careful. Those same osteoarthritis capsules raised the chance of a mild side effect, mostly stomach upset, by 12 points (95% CI 2 to 23), with no serious events. NIH NCCIH lists heartburn, diarrhea and stomach discomfort, says ginger supplements may be safe in pregnancy, and asks anyone on medicines to talk to a clinician first. A review of 149 reports on warfarin, mostly case reports with no dose for tea, lists ginger among foods and herbs that raise bleeding risk with the drug. In a Danish cohort of 225 pregnant women, 11.1% were already taking ginger supplements, mainly as a health boost.

Sources

1. gt8-13 · food survey dataset
   Tea, ginger, FNDDS code 92306850, fdc_id 2710507: Energy 1 KCAL per 100 g; 1 cup 240 g; 1 small 360 g = 3.6 KCAL
   USDA FNDDS 2021-2023, Tea, ginger, fdc_id 2710507 · checked 2026-09-30
2. ev-gitwl-01 · RCT
   There was a significant effect of treatment (ginger vs no ginger = 42.7±21.4kcal/d, P=0.049) but no time or treatment x time interaction on TEF (Figure 1).
   Metabolism, 2012 · checked 2026-10-07
3. ev-gitwl-02 · RCT
   AUC for VAS ratings was significantly lower for questions related to hunger (P=0.002) and prospective food intake (P=0.004) after ginger consumption compared to control (Figure 2).
   Metabolism, 2012 · checked 2026-10-07
4. ev-gitwl-05 · meta-analysis of RCTs
   The meta-analysis showed a significant association between ginger supplementation and a reduction in body weight (WMD, -1.52 kg; 95%CI, -2.37, -0.66; P < 0.001), BMI (WMD, -0.58 kg/m2; 95%CI, -0.87, -0.30; P < 0.001), WC (WMD, -1.04 cm; 95%CI: -1.93, -0.15; P = 0.021), and percent body fat consumption (WMD, -0.87%; 95%CI, -1.71, -0.03; P = 0.042).
   Nutr Rev, 2024 · checked 2026-10-07
5. gt8-01 · systematic review
   A statistically significant very large positive effect of ginger tea consumption was also found on overall CINV severity; however, certainty in this effect was very low.
   Clin Nutr, 2022 · checked 2026-09-30
6. gt8-06 · meta-analysis of RCTs
   However, it was found that the ginger supplement intake group, which took not more than 1 g of ginger supplementation per day for above four days, had significantly less acute vomiting than the control group (OR 0.30; 95% CI 0.12 to 0.79; p = 0.02; I2 = 36%).
   Nutrients, 2022 · checked 2026-09-30
7. gt8-12 · RCT
   Both groups were administered 200 mL of an oral glucose tolerance test (OGTT), after which participants in the intervention group ingested 100 mL of ginger extract (0.2 g/100 mL). ... In the intervention group, the incremental area under the curve for glucose levels decreased significantly (p < 0.001) and the maximum glucose concentration significantly reduced (p < 0.001).
   Foods (Basel), 2023, PMID 36900554 · checked 2026-09-30
8. ev-gitwl-10 · agency fact sheet
   Ginger can have side effects such as abdominal discomfort, heartburn, diarrhea, and mouth and throat irritation when taken orally.
   NCCIH, Ginger: Usefulness and Safety (fact sheet), last updated February 2025 · checked 2026-10-07
9. gt8-09 · systematic review
   While most food, herbs and supplements can be safely taken in moderation, healthcare professionals should be aware of the increased risk of bleeding when taking several food and herbs. These include Chinese wolfberry, chamomile tea, cannabis, cranberry, chitosan, green tea, Ginkgo biloba, ginger, spinach, St. John's Wort, sushi and smoking tobacco.
   Br J Clin Pharmacol, 2021 · checked 2026-09-30
10. gt8-14 · meta-analysis of RCTs
    The meta-analysis of five trials (593 participants) showed moderate-quality evidence for a statistically significant reduction in pain as compared with placebo (SMD = –0.30, 95% CI = –0.50 to –0.09, P = 0.005, I2 = 27%). ... Compared with placebo, a 12% greater risk of experiencing an adverse event was noted following ginger (risk difference [RD] = 0.12, 95% CI = 0.02 to 0.23, P = 0.02, I2 = 49.00%)
    Pain Med, 2019 · checked 2026-09-30
11. ev-gitwl-08 · cross-sectional survey
    On average, ginger beer (38.5±9.9 g/330 mL) contained the highest amounts of sugars and ginger ale (22.9±7.7 g/330 mL) contained the lowest.
    BMJ Open, 2016 · checked 2026-10-07
12. ev-gitwl-11 · agency fact sheet
    If you take any type of medicine, talk with your health care provider before using ginger or any other herbal products; some herbs and medicines interact in harmful ways.
    NCCIH, Ginger: Usefulness and Safety (fact sheet), last updated February 2025 · checked 2026-10-07
13. gt8-07 · RCT
    Resting state energy expenditure was measured using indirect calorimetry and for 6h after consumption of a breakfast meal with or without 2 g ginger powder dissolved in a hot water beverage. ... There was a significant effect of ginger on thermic effect of food (ginger vs control=42.7±21.4 kcal/d, P=.049) but the area under the curve was not different (P=.43).
    Metabolism, 2012 · checked 2026-09-30
14. gt8-08 · RCT
    This clinical trial included 204 T2DM patients randomly assigned to four intervention groups receiving 3 g cinnamon, 3 g cardamom, 1 g saffron or 3 g ginger with three glasses of black tea, and one control group consuming only three glasses of tea without any herbals, for 8 weeks. ... No significant difference was found between various medicinal plants in terms of influencing BP, serum soluble (s)ICAM-1 concentrations and anthropometric measures.
    Blood Press, 2016 · checked 2026-09-30
15. ev-gitwl-07 · RCT
    Over 12 weeks, ginger supplementation resulted in a slight but statistically significant decrease in all anthropometric measurements and total appetite score as compared with placebo group, which were more pronounced in subjects with the AA genotype for uncoupling protein 1 and Trp64Trp genotype for ß3-adrenergic receptor gene.
    Phytother Res, 2015 · checked 2026-10-07
16. ev-gitwl-09 · prospective cohort
    The CAM therapies associated with an increased risk of self-reported bleeding included cayenne, ginger, willow bark, St. John's wort, and coenzyme Q(10).
    Pharmacotherapy, 2007 · checked 2026-10-07
17. gt8-02 · meta-analysis of RCTs
    The result demonstrated that ginger intervention has significant effect in improving general symptom of NVP [OR = 7.475, 95% CI = (4.133, 13.520), I2 = 30.1%], relieving severity of nausea [SMD = 0.821, 95% CI = (0.585, 1.056), I2 = 38.9%], but not significant in reducing vomiting [SMD = 0.549, 95% CI = (-0.268, 1.365), I2 = 91.4%], compared with placebo.
    J Matern Fetal Neonatal Med, 2022 · checked 2026-09-30
18. gt8-03 · umbrella review
    Taking ginger supplements (usually between 450 and 1950 mg daily) significantly decreases the severity and occurrence of nausea and vomiting compared to a placebo. ... Numerous studies have shown that ginger does not raise the risk of adverse effects, such as spontaneous abortion or side effects like heartburn and drowsiness, when compared to a placebo or vitamin B6.
    Phytother Res, 2026 · checked 2026-09-30
19. gt8-05 · meta-analysis of RCTs
    Ginger supplementation was associated with a statistically significant reduction in fasting blood sugar (FBS) (MD -16.27 mg/dl, 95% CI (-25.75, -6.80), I2 = 86.39%), hemoglobin A1c (HbA1c) (MD -0.41%, 95% CI (-0.63, -0.20), I2 = 92.09%)
    Syst Rev, 2026 · checked 2026-09-30
20. gt8-10 · prospective cohort
    Ginger supplements were consumed by 11.1%, mainly as health boost and 87.1% reported consumption of licorice.
    BMC Complement Altern Med, 2019 · checked 2026-09-30
21. gt8-11 · agency guidance
    Ginger can have side effects such as abdominal discomfort, heartburn, diarrhea, and mouth and throat irritation when taken orally. ... The use of ginger dietary supplements during pregnancy may be safe. ... If you take any type of medicine, talk with your health care provider before using ginger or any other herbal products; some herbs and medicines interact in harmful ways.
    NIH NCCIH, Ginger: Usefulness and Safety, updated February 2025 · checked 2026-09-30
22. ev-gitwl-03 · RCT
    Dried ginger powder (2g, The McCormick Science Institute, McCormick & Company, Inc., Sparks, MD) was dissolved in hot water for the ginger test day.
    Metabolism, 2012 · checked 2026-10-07
23. ev-gitwl-04 · RCT
    In conclusion, no reliable treatment effects on appetite, EI or energy balance were observed, although mustard tended to be thermogenic at this dose.
    Br J Nutr, 2013 · checked 2026-10-07
24. ev-gitwl-06 · meta-analysis of RCTs
    Ginger supplementation does not seem effective in improving major measurements/indices of weight, including body weight and BMI.
    Complement Ther Med, 2025 · checked 2026-10-07
25. gt8-04 · meta-analysis of RCTs
    Ginger supplementation significantly reduced SBP (WMD: -5.03 mmHg, 95% CI: -8.49, -1.57; p = 0.004) and DBP (WMD: -2.03 mmHg, 95% CI: -3.90, -0.15; p = 0.034).
    J Hum Nutr Diet, 2026 · checked 2026-09-30