Does tribulus raise testosterone?

Not in humans. A trial with 10 and 20 mg per kilo a day for four weeks did not move testosterone, androstenedione or luteinising hormone versus placebo, and a systematic review of eleven papers concludes it is ineffective at raising it and the marketing claims are unfounded.

Then why do some people say they notice it?

Because it is almost always taken within a multi-ingredient formula and during a period when people also train and eat better. The review suggests the effects that are observed could come from the nitric oxide pathway rather than hormones.

Can tribulus make you fail a drug test?

The trial in elite rugby players measured the urinary testosterone/epitestosterone ratio precisely because of that concern, and it did not change it. That said, the real risk of any supplement for a registered athlete is contamination in the tub, which is what a batch-testing certification covers.

It is its traditional use and the reason it is called an aphrodisiac herb, but the systematic review does not find sufficient support in humans. With a real sexual function problem, the right step is a medical consultation.

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Tribulus · Weak evidence

What tribulus is for and what the evidence says

The short answer. Tribulus is sold to raise testosterone, and that is exactly the claim the evidence does not support. One trial measured testosterone, androstenedione and luteinising hormone in young men for four weeks and found no difference versus placebo. A trial in elite rugby players found no more strength or lean mass than placebo either. And a systematic review concludes that the commercial testosterone claims are unfounded. It is one of the clearest cases on the site: the promise and the data go in different directions.

Reviews find no consistent effect. It is listed because it sells, not because it works. No figure on this page is attributed to a specific product: the effect belongs to the ingredient and every number carries its source next to it.

01 What it does and how much

Each row is a measured effect, with the figure the study gives and the source number. Where the evidence gives no figure, the column says so instead of making up a percentage.

Effects of tribulus with their source
Effect	How much	Detail
Blood testosterone	no change	With 10 and 20 mg per kilo a day for four weeks in young men, neither testosterone, androstenedione nor luteinising hormone separated from the control group. All values stayed within the normal range. [1]
Strength after five weeks	no difference	In elite rugby players doing pre-season weights, strength went up, but it went up the same with tribulus as with placebo. What moved it was training. [2]
Fat-free mass	no difference	Same trial, same result: no difference between groups. The rapid gains some manufacturers advertise did not appear. [2]
Testosterone in humans (review)	no effect	The systematic review pools eleven papers and concludes tribulus is ineffective at raising testosterone in humans, and therefore the commercial claims are unfounded. [3]
Risk of failing a drug test	does not alter the T/E ratio	The rugby trial specifically measured the urinary testosterone/epitestosterone ratio and it did not move. The concern about failing a test by taking it was not confirmed there. [2]

02 How to take it

Dose. 10 to 20 mg per kilo a day split into three servings, or 450 mg of extract a day, the regimes used in the trials.
When. There is no evidence-backed timing, because there is no effect to optimise.
How long before you notice it. The trials ran to four and five weeks without finding differences.

Details that change the result

Labels often highlight the saponin percentage. There is no evidence that a higher percentage translates into a hormonal effect, because there is no hormonal effect to scale up.
The review suggests that the physiological effects that are seen could come from nitric oxide release, not testosterone.
When some effect appears in humans it is within combination formulas, where there is no way of knowing which ingredient caused it.
A product sold as a hormone precursor that does not move hormones is not a bad product: it is a product that does not do what the pack says.

03 When it makes sense and when it does not

Worth it if

There is no sports case that justifies the cost on the available evidence.
With a real hormonal or sexual function problem, the route is a medical consultation and a blood test, not a herbal capsule.

Not worth it if

To raise testosterone: it is the claim the evidence contradicts most directly.
To gain strength or muscle in pre-season, which is exactly where the trial in elite athletes saw nothing.
As an alternative to looking at sleep, food and training load, which is where performance really moves.

04 Sources

Every figure above comes from here. They are position stands from scientific societies, meta-analyses and peer-reviewed reviews: if a claim cannot hang from one of these lines, it is not on the page. References are cited in their original form.

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. 21 hombres de 20 a 36 anos, 10 y 20 mg/kg/dia durante 4 semanas: sin diferencias significativas frente a control en testosterona, androstenediona ni hormona luteinizante. doi:10.1016/j.jep.2005.05.017
Rogerson S 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. 22 jugadores, 450 mg/dia durante 5 semanas: fuerza y masa libre de grasa aumentaron sin diferencias entre grupos; el cociente testosterona/epitestosterona en orina no se altero. doi:10.1519/R-18395.1
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. Once estudios incluidos: la evidencia disponible indica que el tribulus es ineficaz para aumentar la testosterona en humanos y las afirmaciones comerciales no estan fundamentadas. doi:10.3109/19390211.2014.887602

This is not medical advice. It is what some studies say about an ingredient, not a protocol for you. With an illness, medication or pregnancy involved, the decision belongs to a healthcare professional who knows you.

Questions about tribulus

Answered with the data on this page

Does tribulus raise testosterone?: Not in humans. A trial with 10 and 20 mg per kilo a day for four weeks did not move testosterone, androstenedione or luteinising hormone versus placebo, and a systematic review of eleven papers concludes it is ineffective at raising it and the marketing claims are unfounded.
Then why do some people say they notice it?: Because it is almost always taken within a multi-ingredient formula and during a period when people also train and eat better. The review suggests the effects that are observed could come from the nitric oxide pathway rather than hormones.
Can tribulus make you fail a drug test?: The trial in elite rugby players measured the urinary testosterone/epitestosterone ratio precisely because of that concern, and it did not change it. That said, the real risk of any supplement for a registered athlete is contamination in the tub, which is what a batch-testing certification covers.
Does it help libido?: It is its traditional use and the reason it is called an aphrodisiac herb, but the systematic review does not find sufficient support in humans. With a real sexual function problem, the right step is a medical consultation.

And now, which to buy

Prices, kept apart from the evidence

This page explains what tribulus does and deliberately names no brand. The comparison is the other half: 24 products from 4 stores from €0.036 per capsule, sorted by price and by how verifiable their certification is.

See the tribulus comparison

Other guides

What each supplement does, with its sources