Tribulus Terrestris: Benefits, Dosage and Side Effects

Proposed to work through protodioscin, a steroidal saponin said to raise luteinising hormone and therefore testosterone. Human trials have largely failed to demonstrate that chain. An independent effect on nitric oxide release in erectile tissue is a more plausible reading of the positive sexual-function results, but it remains a hypothesis.

• Sexual function: some trials in men and a randomised trial in women with sexual dysfunction reported improvement in desire and satisfaction scores.
• Testosterone: not demonstrated in healthy men. This is the claim most often made and least often supported.
• Athletic performance: a controlled trial in trained athletes found no improvement in body composition or performance over six weeks.

Honest summary: if you are buying tribulus, buy it for the possibility of a sexual-function effect, not for hormones.

A 2025 systematic review of erectile dysfunction and testosterone outcomes identified ten studies, judged half of them methodologically weak, and rated overall certainty very low. A 2021 randomised trial in CrossFit athletes found no meaningful effect on body composition or performance. A 2014 randomised trial in women with sexual dysfunction is among the more positive results.

Trials use 250-1,500 mg/day of extract, usually standardised to 40-60% saponins. Standardisation matters more than the raw milligram count because saponin content varies enormously between suppliers, and a label that states only 'Tribulus terrestris extract 1,000 mg' tells you very little.

Generally well tolerated at trial doses. GI upset and cramping are the common complaints. Animal work at very high doses has reported adverse effects on sperm parameters, which sits awkwardly with its use in fertility formulas.

May add to the effect of blood-glucose-lowering and blood-pressure-lowering medication. There are case reports of nephrotoxicity linked to tribulus preparations, so people with kidney disease should avoid it. Anyone with a hormone-sensitive condition should discuss it with a prescriber even though the hormonal effect is unproven.