Tribulus is one of the most common ingredients in testosterone boosters. The human research tells a different story from the labels.
No, not reliably. In a 2025 systematic review of 10 human studies, 8 found no change in testosterone, and the two that did were low quality and in men who already had low levels. Tribulus may modestly help erectile function in men with mild to moderate ED, but that evidence is also low quality and the effect doesn't seem to come from higher testosterone. Tribulus is not a treatment for erectile dysfunction; see a doctor about persistent symptoms.
Tribulus terrestris is a flowering plant that has been sold as a testosterone booster for decades. The idea comes largely from animal studies. When researchers tested it in men, most trials found no rise in testosterone.
Two systematic reviews, written more than ten years apart, reach the same verdict. A 2014 review in the Journal of Dietary Supplements concluded that the evidence suggests tribulus is ineffective for increasing testosterone in humans. A 2025 systematic review in Nutrients stated there is no solid evidence that tribulus is a testosterone booster.
Where tribulus may still have a role is sexual function, specifically erections and desire in men with mild to moderate erectile problems. That evidence is weaker than marketing suggests, but it's not nothing.
The 2025 Nutrients review (Vilar Neto and colleagues) pulled together 10 clinical studies with 483 men in total. They included healthy men, men with low sperm counts, men with erectile dysfunction, men with erectile problems plus low testosterone, and men with unexplained infertility. All 10 measured testosterone or related hormones.
The reviewers judged the studies too varied and too low in quality to pool into a meta-analysis. About half scored low on a standard trial-quality scale. They also made a fair point in tribulus's defense: the null results mostly came from men with normal testosterone, so they can't be fully applied to men with clinical deficiency. That's a gap in the research, not evidence that it works.
The earlier 2014 review by Qureshi, Naughton and Petroczi found 11 eligible studies. Some animal studies showed higher testosterone. In humans, the only testosterone increases came when tribulus was part of a combination supplement, which makes it impossible to credit tribulus itself.
LiverTox, the NIH database on drug and supplement liver effects, sums it up similarly: its tribulus entry says the hormonal effects seen in animals have not been reproduced consistently in humans.
LiverTox notes that animal studies suggested tribulus raises testosterone. Animal doses don't translate neatly to people, commercial extracts vary in what they contain, and a hormone signal in a rat doesn't guarantee a measurable change in a man whose levels are already normal. The human trials are the test that counts, and they mostly came back negative.
The more promising evidence is for sexual function rather than hormones. The largest trial in the Nutrients review was Kamenov and colleagues (2017): 172 men aged 18 to 65 with mild to moderate erectile dysfunction and/or low sexual desire, randomized to tribulus or placebo for 12 weeks. Erectile function scores and several other sexual function measures improved more with tribulus than with placebo. Testosterone did not change.
Not every trial agrees. A smaller placebo-controlled study of 30 men (Santos, 2014) found no difference between groups on its erectile function score, and LiverTox notes that some controlled trials found sexual function gains no greater than placebo. Overall, the Nutrients reviewers concluded tribulus at roughly 400 to 750 mg a day for one to three months may improve erectile function in men with mild to moderate ED, but rated the evidence as low quality.
If there's an effect, then, it doesn't seem to run through testosterone. That matters, because many products sell tribulus as a hormone booster rather than for what limited evidence it has.
| Claim | What the evidence shows |
|---|---|
| Raises testosterone in healthy men | Not supported; most trials found no change |
| Raises testosterone in men with low levels | Two low-quality studies found small rises; unproven |
| Improves erectile function | Some positive trials, including one of 172 men; overall low quality |
| Builds muscle or boosts performance | No good evidence of benefit |
Tribulus is generally well tolerated in short trials. LiverTox reports that side effects are usually mild, such as stomach upset, nausea or indigestion, and one trial reported diarrhea, dizziness and nausea in about 10 to 13% of users. The Nutrients review found that included studies didn't report significant adverse events, though one showed a rise in a liver enzyme after treatment.
There are rare case reports of more serious problems. LiverTox describes a case of severe jaundice in a young man taking a tribulus extract (anabolic steroid use was considered the more likely cause) and a report of kidney and liver injury after drinking large amounts of tribulus water. LiverTox classes tribulus as an unproven but possible rare cause of liver injury. Grazing sheep that eat the plant can develop liver damage.
Be cautious or talk to your doctor first if you:
Tribulus is one of the most common testosterone booster ingredients. A 2019 review of 50 booster products in the World Journal of Men's Health found it in about 42% of the products it analyzed, yet found no published data supporting its testosterone claims. When a label leads with tribulus and big hormone promises, that's a mismatch worth noticing. Our list of supplement red flags to watch for covers other warning signs, such as proprietary blends that hide doses.
If you're comparing products, look for ingredients with better human data and doses that match the research. Our guide on how to choose a testosterone supplement walks through that. Other common ingredients have their own mixed records: see our look at tongkat ali and testosterone, and our breakdown of the boron and testosterone research.
If you're dealing with low libido, fatigue or erectile problems, see a doctor before trying any booster. Erectile problems are often linked to blood vessel health, diabetes or medications, and low testosterone is diagnosed with morning blood tests, not symptoms alone.
Tribulus terrestris does not reliably increase testosterone. Most human trials found no change, and reviews from 2014 and 2025 agree there's no solid evidence it works as a testosterone booster. It may modestly help erectile function in men with mild to moderate ED, but that evidence is low quality and the effect doesn't come from higher testosterone. If a product's main selling point is tribulus for testosterone, it's selling a claim the research doesn't back.