Supplements

Tribulus Terrestris

Updated · 24 sources · Editorial policy

Tribulus terrestris is a flowering plant with spiny seeds whose aerial parts and fruits have long been used in traditional medicine as a diuretic, tonic and aphrodisiac. Today its extract is one of the most widely sold “testosterone boosters,” marketed to athletes and bodybuilders on the claim that it raises testosterone (Qureshi et al., J Diet Suppl 2014).

The most important fact for this library: controlled trials in men with normal testosterone have not shown that tribulus raises testosterone, muscle mass or strength. Systematic reviews call the testosterone claims unsubstantiated. The more consistent, though still low-quality, evidence concerns sexual function, especially erectile function, and that effect does not appear to run through testosterone (Vilar Neto et al., Nutrients 2025; Suharyani et al., Int J Impot Res 2026).

This page summarizes what clinical trials, systematic reviews and case reports show. It is for education only and is not medical advice.

Property Detail
Type Herbal extract from the aerial parts or fruit of Tribulus terrestris (family Zygophyllaceae)
Main constituents Steroidal saponins (notably protodioscin and other furostanol saponins), alkaloids and flavonoids; amounts vary with climate and region
Route Oral
Doses in human trials Mostly 450–1,500 mg/day of extract for 1–4 months; products in trials were standardized to roughly 40–60% saponins
Half-life Not established; no human pharmacokinetic studies were found
Testosterone effect No consistent rise in men with normal levels; two low-quality studies in men with low testosterone reported rises of ≈60–70 ng/dL
Best-supported effect Erectile function: IIEF-5 score +3.23 points vs placebo (95% CI 1.89–4.58) in a 2026 meta-analysis
US status Dietary supplement; not FDA-approved for any condition
Elsewhere Sold in Bulgaria as the herbal medicine Tribestan (Sopharma) since the 1970s
WADA status Not named on the 2026 Prohibited List; some products have been found to contain unlisted anabolic steroids

What it is

Tribulus terrestris grows mainly in Africa, Asia, Australia and Europe. It has yellow flowers and seeds with three spines. It was used in traditional Greek, Chinese and Indian (Ayurvedic) medicine for infertility, impotence and low libido, and since the early 1980s it has been sold in Western countries as a testosterone booster and libido enhancer (Pokrywka et al., J Hum Kinet 2014).

The plant contains many compounds rather than one main active ingredient (Pokrywka et al., J Hum Kinet 2014; Vilar Neto et al., Nutrients 2025):

Constituent group Examples Why it comes up
Steroidal saponins (glycosides) Protodioscin, other furostanol saponins Proposed as the active ingredients; most extracts are standardized to them
Alkaloids Several, some named after the plant Action in humans not explained
Flavonoids Various Action in humans not explained

The amount of each compound is not stable and depends on climate and geographic origin (Pokrywka et al., J Hum Kinet 2014). Commercial products are standardized differently. For example, the Bulgarian product Tribestan contains 250 mg of dry herb extract per tablet, standardized to at least 112.5 mg of furostanol saponins (Kamenov et al., Maturitas 2017). In the male trials reviewed in 2025, saponin content ranged from about 40% to 60% of the extract, and one trial did not report it (Vilar Neto et al., Nutrients 2025).

About the “Bulgarian weightlifters” story. Tribulus marketing often credits it for the success of Bulgarian weightlifters in the 1970s and 1980s. A 2014 review notes that more accurate doping controls later revealed anabolic steroid use in these athletes, and that the Bulgarian weightlifting team was excluded from the 2008 Beijing Olympics after 11 doping cases. There is no strong evidence that tribulus contributed to their results (Pokrywka et al., J Hum Kinet 2014).

How it works in the body

No human pharmacokinetic data (absorption, peak level, half-life) for tribulus extract or protodioscin were found. Any half-life quoted for “tribulus” should be treated as unsupported.

The idea that tribulus raises testosterone comes mainly from animal work:

  • Primates, rabbits and rats. In primates given a single intravenous dose of extract (7.5 mg/kg), testosterone rose by 52%, DHT by 31% and DHEAS by 29%. In rabbits given oral extract for 8 weeks, only the DHT increases (≈30%) were significant. In castrated rats, oral extract raised testosterone by 25%. The authors attributed this to protodioscin (Gauthaman and Ganesan, Phytomedicine 2008). Intravenous dosing in animals does not show what an oral supplement does in people.
  • Conflicting animal results. Another study in castrated rats found no change in testosterone after 28 days of high oral doses (Pokrywka et al., J Hum Kinet 2014).
  • Humans. In a placebo-controlled trial in 21 healthy men aged 20–36, 10 or 20 mg/kg/day of extract for 4 weeks did not change serum testosterone, androstenedione or luteinizing hormone (LH, the pituitary signal that drives testosterone production) (Neychev and Mitev, J Ethnopharmacol 2005).

For effects on sexual function, reviewers have proposed increased nitric oxide release (which relaxes blood vessels, including in the penis) as a mechanism that would work independently of testosterone. This has not been directly demonstrated in human trials (Qureshi et al., J Diet Suppl 2014; Vilar Neto et al., Nutrients 2025).

Regulatory status

  • United States. Tribulus is sold as a dietary supplement. Under the Dietary Supplement Health and Education Act of 1994, manufacturers are responsible for the safety and labeling of their products before sale, and the FDA can act against adulterated or misbranded products after they reach the market (FDA). It is not an FDA-approved treatment for any condition (Campanelli et al., Int J Impot Res 2016).
  • Bulgaria. Tribestan, made by Sopharma, has been used there since the 1970s and was tested as an herbal medicine in a phase IV trial (a study done after a product is on the market) (Pokrywka et al., J Hum Kinet 2014; Kamenov et al., Maturitas 2017).
  • Sport. Tribulus is not named on the WADA 2026 Prohibited List (WADA 2026 Prohibited List). The risk for tested athletes is contamination, covered below.

What the research shows

Testosterone in men

Several systematic reviews reach the same conclusion:

  • A 2014 review of 11 studies found that tribulus raised testosterone in some animal studies, but in humans only when it was part of a combined supplement. It concluded that tribulus is ineffective for raising testosterone in humans and that marketing claims are unsubstantiated (Qureshi et al., J Diet Suppl 2014).
  • A 2024 review of 52 studies of 27 proposed “testosterone boosters,” including 4 tribulus studies, found that most fail to raise total testosterone. Tribulus was not among the products it rated effective or possibly effective (Morgado et al., Int J Impot Res 2024).
  • A 2025 review of 10 studies (483 men) found no significant change in androgen levels in 8 of them. Half the studies were rated low in methodological quality (Vilar Neto et al., Nutrients 2025).
  • A 2026 meta-analysis of erectile dysfunction trials found no difference in total testosterone between tribulus and placebo (Suharyani et al., Int J Impot Res 2026).

Individual trials in men:

Trial Design and n Dose and duration Testosterone finding
Neychev and Mitev 2005 Placebo-controlled, 21 healthy men aged 20–36 10 or 20 mg/kg/day, 4 weeks No change in testosterone, androstenedione or LH
Santos et al. 2014 Double-blind RCT, 30 men with ED aged 40 or older 800 mg/day, 30 days Mean total testosterone 417 to 409 ng/dL on tribulus vs 443 to 466 ng/dL on placebo; no benefit
Kamenov et al. 2017 Double-blind RCT, 180 men with mild to moderate ED 1,500 mg/day (Tribestan), 12 weeks Total and free testosterone, DHEA-S and SHBG did not differ from placebo (Vilar Neto et al. 2025)
Roaiah et al. 2017 30 men with unexplained infertility 750 mg/day, 3 months No change in total or free testosterone or LH
GamalEl Din et al. 2019 Placebo-controlled, 70 older men with ED and partial androgen deficiency 750 mg/day, 3 months Total testosterone rose in the tribulus group, from ≈215 to ≈273 ng/dL (Vilar Neto et al. 2025)

The only positive results come from two studies limited to men who started with low testosterone: the GamalEl Din trial and an earlier uncontrolled study from the same Cairo group. Both reported rises of about 60–70 ng/dL, both scored poorly on methodological quality, and both used the same 750 mg/day product. The 2025 reviewers described the size of these rises as clinically small and concluded there is “no robust evidence” that tribulus raises testosterone (Vilar Neto et al., Nutrients 2025).

Erectile function

This is the best-studied use. A 2026 meta-analysis of 8 studies used the International Index of Erectile Function (IIEF), a standard questionnaire in which higher scores mean better function (Suharyani et al., Int J Impot Res 2026):

Outcome Tribulus vs placebo, mean difference (95% CI)
IIEF-5 (short form) +3.23 points (1.89–4.58)
IIEF-15 (full form) +14.44 points (5.75–23.14)
Total testosterone No significant difference
Adverse events No difference in incidence

The largest trial randomized 180 men aged 18–65 with mild or moderate ED, including men with high blood pressure, diabetes and metabolic syndrome, to Tribestan 1,500 mg/day or placebo for 12 weeks. The IIEF score improved more on tribulus, with a difference of 2.70 points (95% CI 1.40–4.01) in the intention-to-treat analysis, along with better intercourse satisfaction, orgasmic function and sexual desire scores. One of the authors worked for the manufacturer (Kamenov et al., Maturitas 2017).

Not every trial agrees. In a smaller trial of 30 men with ED, 800 mg/day for 30 days was no better than placebo; IIEF-5 scores rose in both groups (Santos et al., Actas Urol Esp 2014). The 2025 review found improved erectile function in 3 of the 5 studies that measured it and rated the overall level of evidence as low (Vilar Neto et al., Nutrients 2025).

Female sexual function

A 2020 systematic review found 5 randomized trials (279 women) of tribulus for female sexual dysfunction. After 1–3 months, both premenopausal and postmenopausal women on tribulus had higher sexual-function scores, and premenopausal women had higher serum testosterone after 3 months. No serious adverse events were reported, but the certainty of the evidence was rated very low, and the data were too limited and varied to pool (Martimbianco et al., Rev Bras Ginecol Obstet 2020).

In one of these trials, 45 postmenopausal women with low sexual desire took 750 mg/day of tribulus or placebo for 120 days. On one questionnaire, desire, arousal/lubrication, pain and orgasm scores improved on tribulus but not on placebo; on another, most scores improved in both groups. Free and bioavailable testosterone rose on tribulus. Thirty-six women finished; three in each group left because of side effects (de Souza et al., Menopause 2016).

Muscle, strength and performance

Trials in trained men have not found meaningful gains:

Trial Design and n Dose and duration Main findings
Antonio et al. 2000 Randomized, placebo-controlled, 15 resistance-trained men 3.21 mg/kg/day, 8 weeks with training No change in body weight, body fat or mood; no benefit in strength or muscle endurance over placebo
Rogerson et al. 2007 Double-blind RCT, 22 elite rugby league players 450 mg/day, 5 weeks of preseason training Strength and fat-free mass rose equally in both groups; no change in urinary T/E ratio
Fernández-Lázaro et al. 2021 Single-blind RCT, 30 male CrossFit athletes 770 mg/day, 6 weeks No effect on body composition or overall performance; significant group-by-time interactions only for testosterone and bench press

The 2025 review summarized the effects of tribulus on sports performance and body composition as neutral (Vilar Neto et al., Nutrients 2025).

Male fertility

In 30 men with unexplained infertility, 750 mg/day for 3 months did not change sperm concentration, motility or abnormal forms (Roaiah et al., J Diet Suppl 2017). Other fertility studies have reported benefits but were small and of low methodological quality (Vilar Neto et al., Nutrients 2025).

Side effects and risks

In clinical trials

Short trials, mostly of up to 3 months, reported no more adverse events on tribulus than on placebo (Suharyani et al., Int J Impot Res 2026; Kamenov et al., Maturitas 2017). In the GamalEl Din trial, mean AST (a liver enzyme) rose slightly from 26.5 to 27.8 and mean total PSA (prostate-specific antigen) from 1.4 to 1.7 in the tribulus group, both statistically significant (GamalEl Din et al., Urologia 2019). Long-term safety has not been studied.

Liver and kidney injury (case reports)

Several case reports describe serious liver and kidney injury after tribulus use. These are individual cases, not trial rates, and causality is hard to prove with supplements:

  • An Iranian man who drank tribulus “herbal water” for 2 days to prevent kidney stones had a seizure and very high liver enzymes and creatinine; his symptoms improved and liver enzymes normalized after stopping (Talasaz et al., Nephrol Dial Transplant 2010).
  • A 46-year-old man who took tribulus daily for 2 months developed severe jaundice (bilirubin peaking at 48 mg/dL) and kidney dysfunction (creatinine 7.1). A liver biopsy was consistent with drug-induced liver injury. He was treated with plasmapheresis and recovered (Mohy-Ud-Din and Jonassaint, ACG Case Rep J 2024).

In animals, tribulus has been linked to severe jaundice and death in grazing livestock, and to damage of heart muscle, liver and kidney in goats and sheep whose diet was 80% fresh plant (Mohy-Ud-Din and Jonassaint, ACG Case Rep J 2024; Pokrywka et al., J Hum Kinet 2014).

Other reported reactions

  • Priapism. A 36-year-old man had a priapism (a painful erection that will not subside) lasting 72 hours after taking a tribulus supplement. It required surgery and left him with worse sexual function (Campanelli et al., Int J Impot Res 2016).
  • Gynecomastia. A young weight-trainer developed breast enlargement after taking a tribulus-based herbal tablet as a steroid alternative (Jameel et al., Breast 2004).

Interactions

  • Statins. A 71-year-old man on long-term atorvastatin developed rhabdomyolysis (muscle breakdown) and mild liver enzyme elevation after starting tribulus. The case authors cited research suggesting tribulus is a moderate inhibitor of CYP3A4, the liver enzyme that clears atorvastatin and many other drugs. No formal human interaction study was found (Huff et al., Am J Case Rep 2024).
  • Other drugs. No formal drug-interaction studies in humans were found.

Quality, contamination and drug testing

  • Unlisted steroids. Testing of tribulus products has found anabolic steroids and prohormones (including 4-androstenedione and 19-norandrostenedione) that were not listed on the label. The Australian Institute of Sport classified tribulus and other testosterone boosters in its group of supplements that are banned or at high risk of contamination (Pokrywka et al., J Hum Kinet 2014).
  • Uncontaminated tribulus and doping tests. In the rugby trial, 450 mg/day for 5 weeks did not change the urinary testosterone/epitestosterone (T/E) ratio (Rogerson et al., J Strength Cond Res 2007). After two female athletes cited tribulus use to contest an adverse doping finding, two female volunteers took 500 mg three times a day for 2 days; their T/E ratio, DHEA, LH and carbon-isotope results did not change (Saudan et al., Forensic Sci Int 2008).
  • Product variation. Saponin content depends on where the plant was grown and how it was extracted, so results from one product may not apply to another (Pokrywka et al., J Hum Kinet 2014; Vilar Neto et al., Nutrients 2025).

For other herbs marketed for male hormones, see Tongkat Ali, Fenugreek and Ashwagandha.

Key takeaways

  • Not a testosterone booster in practice. Trials in men with normal testosterone show no rise, and systematic reviews call the marketing claims unsubstantiated.
  • No muscle or strength benefit. Trials in resistance-trained men, rugby players and CrossFit athletes found no meaningful gains over placebo.
  • Some evidence for sexual function. A 2026 meta-analysis found better erectile function scores than placebo, and small trials in women report better sexual-function scores, but the evidence is low to very low quality.
  • Generally well tolerated in short trials. Adverse events matched placebo, but case reports describe serious liver and kidney injury, priapism and a possible statin interaction.
  • Contamination is the main doping risk. Pure tribulus did not change doping-test markers, but some products have contained unlisted anabolic steroids.

Sources

  1. US Food and Drug Administration. Dietary supplements. FDA.
  2. World Anti-Doping Agency. The 2026 Prohibited List. In effect January 1, 2026. WADA 2026 Prohibited List.
  3. Qureshi A, Naughton DP, Petroczi A. A systematic review on the herbal extract Tribulus terrestris and the roots of its putative aphrodisiac and performance enhancing effect. J Diet Suppl. 2014;11(1):64–79. PubMed.
  4. Pokrywka A, Obmiński Z, Malczewska-Lenczowska J, et al. Insights into supplements with Tribulus terrestris used by athletes. J Hum Kinet. 2014;41:99–105. PubMed.
  5. Vilar Neto JO, de Moraes WMAM, Pinto DV, et al. Effects of Tribulus (Tribulus terrestris L.) supplementation on erectile dysfunction and testosterone levels in men: a systematic review of clinical trials. Nutrients. 2025;17(7):1275. PubMed.
  6. Morgado A, Tsampoukas G, Sokolakis I, et al. Do “testosterone boosters” really increase serum total testosterone? A systematic review. Int J Impot Res. 2024;36(4):348–364. PubMed.
  7. Suharyani S, Amanda B, Angellee J, et al. Tribulus terrestris for management of patients with erectile dysfunction: a systematic review and meta-analysis of randomized trials. Int J Impot Res. 2026;38(1):11–18. PubMed.
  8. Neychev VK, Mitev VI. The aphrodisiac herb Tribulus terrestris does not influence the androgen production in young men. J Ethnopharmacol. 2005;101(1-3):319–323. PubMed.
  9. Gauthaman K, Ganesan AP. The hormonal effects of Tribulus terrestris and its role in the management of male erectile dysfunction: an evaluation using primates, rabbit and rat. Phytomedicine. 2008;15(1-2):44–54. PubMed.
  10. Kamenov Z, Fileva S, Kalinov K, Jannini EA. Evaluation of the efficacy and safety of Tribulus terrestris in male sexual dysfunction: a prospective, randomized, double-blind, placebo-controlled clinical trial. Maturitas. 2017;99:20–26. PubMed.
  11. Santos CA Jr, Reis LO, Destro-Saade R, et al. Tribulus terrestris versus placebo in the treatment of erectile dysfunction: a prospective, randomized, double blind study. Actas Urol Esp. 2014;38(4):244–248. PubMed.
  12. GamalEl Din SF, Abdel Salam MA, Mohamed MS, et al. Tribulus terrestris versus placebo in the treatment of erectile dysfunction and lower urinary tract symptoms in patients with late-onset hypogonadism: a placebo-controlled study. Urologia. 2019;86(2):74–78. PubMed.
  13. Roaiah MF, Elkhayat YI, Abd El Salam MA, GamalEl Din SF. Prospective analysis on the effect of botanical medicine (Tribulus terrestris) on serum testosterone level and semen parameters in males with unexplained infertility. J Diet Suppl. 2017;14(1):25–31. PubMed.
  14. Martimbianco ALC, Pacheco RL, Vilarino FL, et al. Tribulus terrestris for female sexual dysfunction: a systematic review. Rev Bras Ginecol Obstet. 2020;42(7):427–435. PubMed.
  15. de Souza KZ, Vale FB, Geber S. Efficacy of Tribulus terrestris for the treatment of hypoactive sexual desire disorder in postmenopausal women: a randomized, double-blinded, placebo-controlled trial. Menopause. 2016;23(11):1252–1256. PubMed.
  16. Antonio J, Uelmen J, Rodriguez R, Earnest C. The effects of Tribulus terrestris on body composition and exercise performance in resistance-trained males. Int J Sport Nutr Exerc Metab. 2000;10(2):208–215. PubMed.
  17. Rogerson S, Riches CJ, Jennings C, et al. The effect of five weeks of Tribulus terrestris supplementation on muscle strength and body composition during preseason training in elite rugby league players. J Strength Cond Res. 2007;21(2):348–353. PubMed.
  18. Fernández-Lázaro D, Mielgo-Ayuso J, Del Valle Soto M, et al. The effects of 6 weeks of Tribulus terrestris L. supplementation on body composition, hormonal response, perceived exertion, and CrossFit performance: a randomized, single-blind, placebo-controlled study. Nutrients. 2021;13(11):3969. PubMed.
  19. Saudan C, Baume N, Emery C, Strahm E, Saugy M. Short term impact of Tribulus terrestris intake on doping control analysis of endogenous steroids. Forensic Sci Int. 2008;178(1):e7–e10. PubMed.
  20. Talasaz AH, Abbasi MR, Abkhiz S, Dashti-Khavidaki S. Tribulus terrestris-induced severe nephrotoxicity in a young healthy male. Nephrol Dial Transplant. 2010;25(11):3792–3793. PubMed.
  21. Mohy-Ud-Din N, Jonassaint N. Severe liver and renal injury from Tribulus terrestris. ACG Case Rep J. 2024;11(2):e01267. PubMed.
  22. Campanelli M, De Thomasis R, Tenaglia RL. Priapism caused by ‘Tribulus terrestris’. Int J Impot Res. 2016;28(1):39–40. PubMed.
  23. Jameel JK, Kneeshaw PJ, Rao VS, Drew PJ. Gynaecomastia and the plant product “Tribulis terrestris”. Breast. 2004;13(5):428–430. PubMed.
  24. Huff R, Karpinska-Leydier K, Maddineni G, Begosh-Mayne D. Rhabdomyolysis risk: the dangers of Tribulus terrestris, an over-the-counter supplement. Am J Case Rep. 2024;25:e943492. PubMed.