You'll find tribulus in a great many testosterone boosters. What human studies report doesn't match what the labels imply.
Mostly no. A 2025 systematic review looked at 10 human studies. Testosterone stayed flat in 8 of them. The other two showed a rise, but both were low quality and enrolled men with low levels to begin with. For erections, tribulus may give a modest benefit to men with mild to moderate ED. That evidence is low quality too, and the benefit doesn't seem to involve higher testosterone. Tribulus is not a treatment for erectile dysfunction; see a doctor about persistent symptoms.
Supplement makers have marketed tribulus terrestris, a flowering plant, as a testosterone booster for decades. Animal studies are where the idea mostly started. In men, most trials found no testosterone rise.
Two systematic reviews, more than ten years apart, reach the same verdict. In its 2014 Journal of Dietary Supplements review, the authors judged tribulus ineffective for raising testosterone in humans, based on the evidence. Then the 2025 Nutrients systematic review said no solid evidence supports tribulus as a testosterone booster.
Sexual function may be where tribulus has some role: erections and desire in men with mild to moderate erectile problems. Marketing oversells this evidence, but it isn't nothing.
Vilar Neto and colleagues wrote the 2025 review in Nutrients. They combined 10 clinical studies with 483 men. The men were a mix: healthy, low sperm count, erectile dysfunction, erectile problems with low testosterone, and unexplained infertility. Every one of the 10 studies tracked testosterone or related hormones.
The reviewers decided the studies differed too much, and were too weak, to combine in a meta-analysis. Roughly half rated low on a standard scale of trial quality. They did concede one thing in tribulus's favor. The null findings came mostly from men with normal testosterone, so they don't fully speak to men with a clinical deficiency. This gap in the research is not evidence that tribulus works.
Qureshi, Naughton and Petroczi wrote an earlier review in 2014 that identified 11 eligible studies. A few animal studies had found higher testosterone. In humans, the only rises happened when tribulus sat inside a combination supplement, so you can't pin them on tribulus.
The NIH database LiverTox, which tracks liver effects of drugs and supplements, agrees. Its tribulus entry states that the hormonal effects seen in animals have not been reproduced consistently in humans.
LiverTox says animal studies pointed to a testosterone rise. Three things limit what that means for men. Doses in animals don't map cleanly onto human ones. Commercial extracts differ in what's inside. And a hormone signal in a rat doesn't promise a measurable change in a man with normal levels. What counts is the human trials, and most were negative.
Sexual function is the more promising area, rather than hormones. Kamenov and colleagues (2017) ran the largest trial in the Nutrients review. They randomized 172 men, aged 18 to 65, who had mild to moderate erectile dysfunction and/or low sexual desire. Half took tribulus and half placebo, for 12 weeks. Tribulus beat placebo on erectile function scores and several other sexual function measures. Testosterone stayed the same.
Other trials disagree. Santos (2014) ran a smaller placebo-controlled study of 30 men and saw no gap between groups on its erectile function score. LiverTox also notes that some controlled trials found sexual function gains that were no better than placebo. The Nutrients reviewers still concluded that roughly 400 to 750 mg a day for one to three months may improve erectile function in men with mild to moderate ED. They graded that evidence as low quality.
That suggests any effect doesn't run through testosterone. It matters because many products pitch tribulus as a hormone booster, not for the limited benefit the evidence suggests.
| Claim | What the research says |
|---|---|
| Raises testosterone in healthy men | Not supported; most trials saw no change |
| Raises testosterone in men with low levels | Two low-quality studies saw small rises; unproven |
| Improves erectile function | Some positive trials, one of them in 172 men; low quality overall |
| Builds muscle or boosts performance | No good evidence of benefit |
In short trials, people generally tolerated tribulus. LiverTox describes side effects as usually mild (stomach upset, nausea or indigestion). One trial saw diarrhea, dizziness and nausea in about 10 to 13% of users. In the Nutrients review, the included studies reported no significant adverse events, but one found a liver enzyme went up after treatment.
A few rare case reports involve more serious harm. One LiverTox case is a young man with severe jaundice who was taking a tribulus extract; anabolic steroid use was considered the likelier cause. Another is a report of kidney and liver injury after someone drank large amounts of tribulus water. LiverTox calls tribulus an unproven but possible rare cause of liver injury. Sheep grazing on the plant can also develop liver damage.
Be careful, and talk to your doctor first, if you:
In a 2019 review of 50 booster products, published in the World Journal of Men's Health, tribulus appeared in about 42% of the products analyzed. The review found no published data to back their testosterone claims. A label that opens with tribulus and large hormone promises is a mismatch. For more warning signs, such as proprietary blends that hide doses, see our supplement red flags list.
When comparing products, favor ingredients with stronger human data and doses in line with the research. Our guide on how to choose a testosterone supplement shows how. Other popular ingredients have mixed records of their own. Read about tongkat ali and testosterone and about the boron and testosterone research.
See a doctor before trying any booster if you have low libido, fatigue or erectile problems. Blood vessel health, diabetes and medications are frequent causes of erectile problems. Doctors diagnose low testosterone with morning blood tests, not symptoms alone.
Reviews from 2014 and 2025 agree: no solid evidence supports tribulus terrestris as a testosterone booster, and most human trials saw no change. Erectile function is a different matter. Tribulus may modestly help men with mild to moderate ED, though that evidence is low quality and the effect doesn't come from higher testosterone. Any product built around tribulus for testosterone is selling a claim the research doesn't back.