Verdict: At best a small rise in total testosterone with very low certainty, no effect on free testosterone or VO2max
Safety: Digestive upset, can lower blood sugar, possible allergic reactions; not safe in pregnancy above food amounts
Key takeaways
A 2020 meta-analysis of four trials found fenugreek extract raised total testosterone, but a larger 2026 meta-analysis found only a small effect with very low certainty
Free testosterone, the fraction that is biologically active, did not change in the pooled analysis
Fenugreek does not raise VO2max, and most trials are small, short and test branded extracts
Fenugreek is a kitchen spice that has become a mainstay of "natural testosterone" products. Several small trials with branded extracts report higher testosterone and better strength, and a 2020 meta-analysis gave the idea a boost. A larger 2026 meta-analysis paints a more cautious picture.
What it is
Fenugreek (Trigonella foenum-graecum) is a plant whose seeds are used in curries and traditional medicine. Supplements are concentrated seed extracts, often standardised to compounds called saponins or to a glycoside fraction. These compounds are suggested to influence testosterone metabolism, though the mechanism in humans is unclear.
Does it raise VO2max?
No. There is no evidence that fenugreek increases VO2max or the factors that set it, such as heart size, blood volume and haemoglobin (see what limits VO2max). Even if it raised testosterone slightly within the normal range, that is far from the levels that change haemoglobin meaningfully (see testosterone, endurance training and VO2max).
Does it improve endurance performance?
No trial shows that it does. Research has focused on testosterone, strength and body composition.
Mansoori et al., 2020 — meta-analysis of four trials
This meta-analysis (Phytother Res, 2020) pooled four randomised trials comparing fenugreek extract with a control and found a significant effect on total serum testosterone in men. Four trials is a small base, and they used different extracts and doses.
Yang et al., 2026 — a larger and stricter update
A newer systematic review (Front Nutr, 2026) included 13 placebo-controlled trials and graded the evidence:
- Across six trials, fenugreek showed a small favourable effect on total testosterone (standardised mean difference 0.25, 95% CI 0.02 to 0.48).
- For free testosterone, the pooled result across five trials was imprecise and not significant.
- None of the trials was judged at low risk of bias, and the certainty of evidence was rated very low for both outcomes.
In plain terms: there may be a small bump in total testosterone, but we cannot be confident, and the active fraction does not clearly change.
Strength and body composition
- Wankhede et al., 2016: 60 healthy men took 600 mg a day of a fenugreek glycoside extract or placebo during 8 weeks of supervised resistance training. The authors reported anabolic and androgenic effects and better body fat, with no side effects. It was a single, fairly small trial of one branded extract.
- Albaker, 2023: a systematic review of six randomised trials found four reporting better strength, muscular endurance, lean mass or body fat with fenugreek. Two trials were very small. The author also advised awareness of doping and possible liver and kidney effects.
How it is used in studies
Trials typically use a few hundred milligrams a day of a standardised seed extract, often for about 8 weeks alongside resistance training; the 60-man trial above used 600 mg a day. Extracts differ in what they are standardised to, so results from one brand do not apply to all.
Side effects, safety and anti-doping
Fenugreek is a common food, but concentrated extracts are different. According to the US National Center for Complementary and Integrative Health (NCCIH):
- It can cause diarrhoea, nausea and other digestive symptoms.
- Large doses may lower blood sugar too far, which matters if you take diabetes medication.
- It can cause allergic reactions, sometimes serious.
- It is not safe in pregnancy in amounts above those found in food.
Fenugreek is not banned in sport, but "testosterone booster" blends are a high-risk product category. Geyer and colleagues (2004) found that 14.8% of 634 supplements contained anabolic steroids not declared on the label, and FDA warnings link most adulterated muscle-building products to hidden steroids or steroid-like drugs (Tucker et al., 2018). Under WADA's strict liability rule, an athlete is responsible for any banned substance found, however it got there. Competitive athletes should use products certified by Informed Sport or NSF Certified for Sport.
This page is not medical advice. Men with symptoms of low testosterone, such as low libido, erectile problems, fatigue or loss of muscle, should see a doctor and get a proper blood test.
Who might benefit
Strength athletes curious about a low-risk herbal option might see a small effect, but it is uncertain. Everyone else is better served by creatine, adequate protein and consistent strength training, which have much stronger evidence.
Bottom line
Fenugreek may slightly raise total testosterone, but the latest meta-analysis rates that evidence very low certainty and finds no clear change in free testosterone. Strength gains come mainly from small trials of branded extracts. It does not raise VO2max. Compare tongkat ali and D-aspartic acid, or see how to improve VO2max.
Frequently asked questions
Does fenugreek increase testosterone?
Possibly a little. A 2026 meta-analysis of randomised trials found a small rise in total testosterone but no clear change in free testosterone, and rated the certainty of evidence as very low.
Does fenugreek help build strength?
A few small trials, mostly with branded extracts during about 8 weeks of resistance training, report gains in strength or body composition. Larger independent trials are lacking, and training itself drives most of the change.
Is fenugreek safe?
Fenugreek is a common food spice. As a supplement it can cause digestive upset, lower blood sugar and allergic reactions, and NCCIH says it is not safe in pregnancy in amounts above those in food.
Does fenugreek help endurance or VO2max?
No study shows it raises VO2max or improves endurance performance. It is marketed for testosterone and strength, not aerobic fitness.
Sources
- Mansoori A, Hosseini S, Zilaee M, Hormoznejad R, Fathi M. Effect of fenugreek extract supplement on testosterone levels in male: a meta-analysis of clinical trials. Phytother Res. 2020;34(7):1550–1555.
- Yang P, Niu Z, Guo J, Huang T, Chang D, Huang X. Effects of oral fenugreek-derived preparations on testosterone-related outcomes in adult men: a systematic review and meta-analysis of randomized placebo-controlled trials. Front Nutr. 2026;13:1903508.
- Wankhede S, Mohan V, Thakurdesai P. Beneficial effects of fenugreek glycoside supplementation in male subjects during resistance training: a randomized controlled pilot study. J Sport Health Sci. 2016;5(2):176–182.
- Albaker WI. Fenugreek and its effects on muscle performance: a systematic review. J Pers Med. 2023;13(3):427.
- National Center for Complementary and Integrative Health. Fenugreek. NIH.
- Geyer H, Parr MK, Mareck U, Reinhart U, Schrader Y, Schänzer W. Analysis of non-hormonal nutritional supplements for anabolic-androgenic steroids: results of an international study. Int J Sports Med. 2004;25(2):124–129.
- Tucker J, Fischer T, Upjohn L, Mazzera D, Kumar M. Unapproved pharmaceutical ingredients included in dietary supplements associated with US Food and Drug Administration warnings. JAMA Netw Open. 2018;1(6):e183337.