Tribulus terrestris (puncture vine, gokshura) is the most heavily marketed "testosterone booster" and the most clearly tested: repeated randomized trials in athletes and healthy men show no increase in testosterone and no performance or muscle benefit. Small trials do suggest modest libido improvements in men and women with low sexual desire, and mixed results in mild erectile dysfunction — effects that appear independent of hormones. Typical doses are 250–1,500 mg/day of standardized extract. It is generally tolerated short term; avoid in pregnancy and hormone-sensitive cancers, and note rare reports of toxicity with high, prolonged dosing.
What tribulus is
Tribulus terrestris — puncture vine, named for spiked fruits sharp enough to flatten bicycle tires — is a hardy creeper found across Asia, Africa and southern Europe, used in Ayurvedic (gokshura) and traditional Chinese medicine. Supplements use fruit or root extracts standardized to steroidal saponins, especially protodioscin, the compound the marketing leans on.
It is likely the best-selling single "testosterone" herb in the world. It is also the best-refuted, which makes it worth reading about even if you never buy it.
Evidence by use
Testosterone — asked and answered. Randomized controlled trials in elite rugby players, resistance-trained men, and healthy volunteers — at doses from 450 mg to 1,500 mg/day and durations to eight weeks — consistently found no change in total or free testosterone versus placebo, and no change in the androgen markers that would accompany a real rise. Reviews of the clinical literature reach the same conclusion. Whatever tribulus does, raising testosterone in men is not it. (The wider category scorecard: Do testosterone boosters work?)
Muscle and performance. The same athlete trials measured strength, body composition and performance: no benefit over placebo.
Libido. Here the record is more interesting: several small placebo-controlled trials — in men with reduced desire and in women with hypoactive sexual desire — report improved desire and satisfaction scores at 250–750 mg/day of standardized extract, without hormonal change. Small trials, one dominant branded extract, but a consistent direction.
Erectile function. Mixed: an adequately sized trial in mild-to-moderate ED using a specific extract reported improvement over placebo; others found nothing. Weighed against citrulline's cleaner mechanism-plus-trial story, it is a second-tier option at best — see Can supplements help erectile dysfunction?
Blood sugar, urinary stones, heart — isolated small studies; nothing usable.
Doses studied
250–1,500 mg/day of fruit/root extract, commonly standardized to 45–60% saponins or a stated protodioscin content, for 4–12 weeks. Saponin chemistry varies with plant origin — Bulgarian and Indian material differ measurably — which may explain some trial inconsistency and makes standardization worth insisting on.
Safety
Short-term use at studied doses: occasional stomach upset and reflux; generally unremarkable in trials. The serious print:
- Pregnancy — avoid; animal data suggest fetal harm.
- Hormone-sensitive cancers — avoided on principle given saponin activity.
- Diabetes and blood-pressure medication — possible additive lowering; monitor.
- Rare toxicity reports — isolated human cases of kidney and liver injury with very high or prolonged intake, and a well-described livestock neurotoxicity syndrome from heavy grazing. Ordinary supplement doses have not shown this, but it argues against megadosing an ingredient with modest upside.
- Contamination — see the athlete FAQ; this category's adulteration record extends to tribulus products.
Where it appears in supplements
In nearly every multi-ingredient "T-booster" and many libido blends — almost always inside a proprietary blend, dose unstated, reputation doing the work the evidence cannot. Its presence on a label is a reasonable proxy for how a formula was designed: around search volume rather than trial data. Our men's health product research treats it accordingly.
Bottom line
For testosterone or performance, tribulus is a settled no — spend nothing. For low sexual desire specifically, a standardized extract at 250–750 mg/day is a modest, low-risk experiment a doctor can sanction, with expectations set by small trials rather than large legends. The most valuable thing tribulus offers the supplement buyer is the lesson in how long a claim can outlive its refutation.
Frequently asked questions
Where did the testosterone reputation come from, if trials are negative?
From 1970s–80s Eastern European animal studies and athlete lore, amplified by supplement marketing before controlled human trials existed. When those trials arrived — in rugby players, elite athletes, resistance-trained men and ordinary volunteers — hormone levels did not move. The reputation outlived its evidence by decades, which is precisely why "traditionally used for" and "shown in studies to" deserve different weights.
Can tribulus cause a failed drug test?
Tribulus itself contains no banned substances. The documented risk is contamination: tribulus products adulterated with prohormones or steroids have caused positive tests, which is why anti-doping bodies warn athletes off unverified brands. Third-party "informed sport" certification is the minimum for tested athletes.
Does it help libido even though testosterone doesn't change?
That is what the small positive trials suggest — improved desire scores in people with low desire, without hormone changes. Proposed explanations involve protodioscin's effects on nitric-oxide signalling. The trials are small and use one Bulgarian extract prominently; treat it as a modest, unsettled effect.
What is gokshura?
The same plant in Ayurvedic usage, traditionally for urinary and vitality complaints. Traditional prominence explains availability, not efficacy — the trial record above applies regardless of the aisle it is sold in.
References
- MedlinePlus, U.S. National Library of Medicine. Testosterone Levels Test (2024). https://medlineplus.gov/lab-tests/testosterone-levels-test/
- National Center for Complementary and Integrative Health (NCCIH). Diabetes and Dietary Supplements: What You Need To Know (2021). https://www.nccih.nih.gov/health/diabetes-and-dietary-supplements-what-you-need-to-know
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