Tribulus Terrestris and Testosterone: Where the Myth Came From
Does tribulus terrestris raise testosterone?
No. A 2025 systematic review of ten clinical studies in 483 men found that eight reported no significant change in androgen profile, and a 2026 meta-analysis of eight studies found no significant difference in total testosterone between tribulus and placebo. The more defensible signal is on erectile-function questionnaires, and even that rests on wide confidence intervals and studies of mixed quality.
- Testosterone: two independent pooled analyses found no reliable effect in men.
- Erectile function: pooled IIEF gains over placebo, but very wide intervals and one null high-quality trial.
- Doses studied: 400 to 750 mg per day for one to three months.
Tribulus terrestris is the ingredient that built the modern testosterone-booster aisle, and it is also the ingredient with the clearest evidence that the aisle’s central promise does not hold. Two decades of trials have now been pooled twice, and the pattern is consistent: tribulus does not reliably raise testosterone in men, while a weaker and more interesting signal shows up on erectile-function questionnaires.
Where the tribulus testosterone myth came from
The claim traces back to a saponin called protodioscin and to animal work suggesting it could influence androgen signalling. Sports marketing in the 1990s carried that from rodent studies to supplement labels without waiting for human trials, and the phrase “natural testosterone booster” largely dates from that transfer. A systematic review of tribulus terrestris and its putative aphrodisiac and performance-enhancing effect put the situation plainly: the aphrodisiac and performance claims had spread far ahead of the evidence for them.
What the pooled human evidence shows about testosterone
The most detailed recent appraisal is a 2025 systematic review in Nutrients. the review of tribulus supplementation on erectile dysfunction and testosterone levels in men included ten studies covering 483 men aged sixteen to seventy, at doses of 400 to 750 mg per day for one to three months, and rated half of them low methodological quality on the Jadad scale. Eight of the ten reported no significant change in androgen profile. Only two showed a significant within-group rise in total testosterone, of low clinical magnitude — on the order of 60 to 70 ng/dL — and both were in men who were hypogonadal to begin with.
A 2026 meta-analysis reached the same conclusion by a different route. a systematic review and meta-analysis of randomised trials of tribulus terrestris in patients with erectile dysfunction pooled eight studies and found no significant difference in total testosterone between tribulus and placebo. Two independent syntheses, one narrative and one quantitative, agreeing that the flagship claim is unsupported is about as settled as this literature gets.
The erectile-function signal, and why it is weaker than it looks
The same meta-analysis did find something. On the International Index of Erectile Function, tribulus outperformed placebo on the abridged IIEF-5 (mean difference 3.23, 95% CI 1.89 to 4.58) and on the full IIEF-15 (mean difference 14.44, 95% CI 5.75 to 23.14), with no difference in adverse events between groups. The systematic review found erectile dysfunction improved in three of the five studies that measured it.
Three caveats belong beside that. The IIEF-15 interval running from 5.75 to 23.14 is enormously wide, which means the pooled estimate is unstable. Half the underlying studies were rated low quality. And the single best-controlled trial found nothing: a prospective, randomised, double-blind trial of tribulus terrestris versus placebo in erectile dysfunction gave 800 mg per day for thirty days to thirty men aged forty and over with erectile dysfunction and reported that scores rose in both arms with no significant difference between them — the classic signature of a placebo response on a self-reported questionnaire.
| Marketing claim | What the evidence found | Confidence |
|---|---|---|
| Raises testosterone in healthy men | Eight of ten studies found no androgen change; pooled analysis found no difference versus placebo | Reasonably settled negative |
| Raises testosterone in low-T men | Two studies showed small within-group rises of about 60 to 70 ng/dL | Weak, uncontrolled |
| Improves erectile function | Pooled IIEF gains over placebo, but very wide intervals and the best-controlled trial was null | Low-quality positive |
| Builds muscle or strength | Not supported by the reviews of the ingredient class | Unsupported |
| Safe at typical doses | No difference in adverse events versus placebo in the pooled trials; one severe case report exists | Generally reassuring, not blanket |
What tribulus does not do
It does not raise testosterone in men whose levels are normal. The reviewers noted that men in the neutral studies did not have low androgens at baseline, which is the population most supplement buyers belong to.
It does not substitute for a diagnosis. If testosterone is genuinely low, that is a clinical finding with clinical causes, and the route through testing is set out in signs of low testosterone and when to test.
It does not rescue a formula built on weak ingredients. Category-wide audits — a review finding that testosterone-boosting supplement compositions and claims are not supported by the academic literature, a systematic review and evidence-based analysis of ingredients in popular male testosterone and erectile dysfunction supplements and an analysis of popular online testosterone-boosting supplements — all found that labels in this aisle routinely promise more than their contents can support.
One severe case report exists. Clinicians described hepatotoxicity, nephrotoxicity and neurotoxicity in a young man who had consumed a tribulus preparation for two days; his symptoms and liver enzymes normalised after he stopped. A single case is not a population risk, but it is a reason to treat concentrated herbal preparations as pharmacologically active rather than as food.
Safety, and the one case worth knowing about
Across the pooled randomised trials, adverse events with tribulus were no more common than with placebo, which is genuinely reassuring for typical supplement doses over one to three months. Set against that, a published case of tribulus terrestris-induced severe nephrotoxicity in a young healthy male documents a severe multi-organ reaction in a previously healthy young man. Both facts are real, and the sensible reading is that tribulus is usually well tolerated but is not inert.
Check which ingredients are doing the work
Horse Boost lists tribulus among nine botanicals inside an 82 mg blend, with only its 5 mg of caffeine broken out. Read the full ingredient list and pricing before you decide.
Order NowHow to read a label that contains tribulus
Treat it as a filler ingredient until proven otherwise. Tribulus is cheap, familiar and recognisable, which makes it useful to a formulator for reasons unrelated to what it does.
Look at what else is in the blend. The botanical with the strongest randomised hormonal evidence in this category is tongkat ali, and the one with the most convincing self-reported drive data is maca root. Neither is tribulus.
Watch for the same overclaim on neighbouring ingredients. Fenugreek and boron both attract the same pattern of enthusiastic marketing running ahead of modest data.
If the goal is erections rather than hormones, the mechanism is blood flow. That is a different pathway with different evidence, covered in L-citrulline versus Viagra.
What the evidence shows, and what it does not
What it shows: across ten clinical studies and 483 men, tribulus at 400 to 750 mg per day did not change androgen profile in eight of them; a pooled meta-analysis of eight studies found no testosterone difference versus placebo; the same meta-analysis found improved IIEF scores versus placebo; adverse events were no more frequent than with placebo.
What it does not show: that tribulus raises testosterone in any population with confidence, that the erectile-function benefit survives high-quality blinding, or that any dose or extract is optimal. The best-designed placebo-controlled trial in the set was null on both endpoints. Tribulus is the clearest example in this aisle of a claim that outlived its evidence.
Related reading on male vitality
- Tongkat ali and the strongest botanical hormone signal
- How testosterone boosters hold up under audit
- Fenugreek: evidence against hype
- Boron, SHBG and free testosterone
- Muira puama and catuaba: two traditional tonics
Frequently asked questions
Does tribulus terrestris increase testosterone?
Not reliably. A 2025 systematic review of ten clinical studies found that eight reported no significant change in androgen profile, and the two that showed a within-group increase involved hypogonadal men and a difference of only about 60 to 70 ng/dL. A separate 2026 meta-analysis of eight studies found no significant difference in total testosterone between tribulus and placebo.
Does tribulus help with erectile dysfunction?
The pooled evidence is more favourable here than for testosterone, with meta-analysed gains on the IIEF-5 and IIEF-15 compared with placebo. The confidence intervals are very wide, half the underlying studies were rated low quality, and a well-designed placebo-controlled trial at 800 mg per day for thirty days found improvements in both arms with no difference between them.
How much tribulus was used in the trials?
The reviewed studies used 400 to 750 mg per day for one to three months, and the best-controlled erectile-dysfunction trial used 800 mg per day for thirty days. Products often list tribulus inside a proprietary blend without disclosing the amount, in which case none of these protocols can be said to apply.
Is tribulus terrestris safe?
In the pooled randomised trials, adverse events with tribulus were no more common than with placebo. There is one published case report of severe liver, kidney and neurological toxicity in a young man after consuming a tribulus preparation, with recovery after stopping. A single case is not a population risk, but concentrated herbal preparations should be treated as pharmacologically active.
References
- Vilar Neto JO 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. PMID 40219032
- Suharyani S 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. PMID 40360723
- Santos CA Jr et al. Tribulus terrestris versus placebo in the treatment of erectile dysfunction: A prospective, randomized, double blind study. Actas Urol Esp, 2014. PMID 24630840
- Qureshi A et al. A systematic review on the herbal extract Tribulus terrestris and the roots of its putative aphrodisiac and performance enhancing effect. J Diet Suppl, 2014. PMID 24559105
- Talasaz AH et al. Tribulus terrestris-induced severe nephrotoxicity in a young healthy male. Nephrol Dial Transplant, 2010. PMID 20667992
- Clemesha CG et al. ‘Testosterone Boosting’ Supplements Composition and Claims Are not Supported by the Academic Literature. World J Mens Health, 2020. PMID 31385468
- Kuchakulla M et al. A systematic review and evidence-based analysis of ingredients in popular male testosterone and erectile dysfunction supplements. Int J Impot Res, 2021. PMID 32358510
- Balasubramanian A et al. Testosterone Imposters: An Analysis of Popular Online Testosterone Boosting Supplements. J Sex Med, 2019. PMID 30770069
- NIH Office of Dietary Supplements - Dietary Supplements: What You Need to Know
Every PubMed reference above was checked against its own PubMed record before publication. Research on an isolated ingredient is not evidence about any finished product.