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Ingredients / Tribulus terrestris
Limited evidence overall 14 articles · reviewed 2 Sep 2026

Tribulus terrestris

Tribulus terrestris L.

Sold as a testosterone booster for three decades. In healthy men, controlled trials do not find a hormonal effect.

What the evidence supports

Limited Testosterone Measured repeatedly in healthy and athletic men. No reliable change against placebo.
Limited Strength & body composition Null in resistance-training trials where diet and programme were controlled.
Moderate Libido Some improvement in self-reported desire, including in women and in men with erectile dysfunction — an effect that appears independent of testosterone.
Limited Fertility markers Sperm-parameter trials are small, uncontrolled, and conflicting.
Dose used in trials
750–1,500 mg

per day of extract standardised to saponins. Commercial saponin content varies enormously between products.

Safety
Mostly tolerated

GI upset is the usual complaint. Isolated reports of kidney and liver injury at high doses exist.

Ask a doctor first if
Three cases

Prostate conditions, hormone-sensitive cancers, or pregnancy.

The trials, individually

Open any one for sample size, funding and what it actually measured.

Rogerson et al. · 22 rugby players · testosterone
Five weeks of training with 450 mg/day. No difference in testosterone, strength or lean mass versus placebo. Small but tightly controlled.
Neychev & Mitev · 21 young men · androgens
Four weeks at three doses. No change in total or free testosterone, LH or androstenedione at any dose.
Kamenov et al. · 180 men · erectile function
Twelve weeks, 750 mg/day. IIEF scores improved versus placebo without a corresponding testosterone change — the strongest positive trial, and manufacturer-supported.

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