Tribulus terrestris

LibidoHormones

Traditional Ayurvedic and TCM herb sold for testosterone — but RCTs don't show testosterone elevation. Real effects are on libido and sexual satisfaction (probably via different mechanisms).

EvidenceLimited (testosterone) / Moderate (sexual function)

Multiple negative trials for testosterone elevation in men. Moderate evidence for libido and sexual function in both sexes. Effects: 4–8 weeks for libido.

Tribulus terrestris (puncture vine) is one of the most-marketed 'testosterone boosters' in supplements — and the marketing is largely wrong. Multiple well-designed trials in men show no significant testosterone elevation. What tribulus does do, with reasonable evidence, is improve libido and sexual satisfaction in both men and women — likely through nitric oxide pathway effects and possibly some central nervous system action. So: useful for sexual function, mostly placebo for testosterone. The Bulgarian variety standardised to protodioscin has the most-studied actives.

Form
Bulgarian Tribulus terrestris extract standardised to ≥40% saponins, with specified protodioscin content. Brand: Tribulus 40% (NOW), Vitanol.
Dose
750–1,500 mg/day standardised extract. Split across the day.
Timing
With food. AM and midday.
Schedule
Cycle: 8 weeks on, 2–4 weeks off.
Side effects
Generally well-tolerated. GI upset, sleep disturbance, irritability in some.
Interactions
Diabetes medications — mild glucose lowering. Antihypertensives — mild BP effects. Lithium — diuretic effect may alter levels.
Contraindications
Pregnancy / breastfeeding. Hormone-sensitive cancers. Active prostate cancer or BPH (unclear safety). Pre-surgery (mild blood pressure effects).
Lab markers
Total + free testosterone, estradiol if tracking hormonal effects (mostly to confirm tribulus doesn't change them).
Food sources
Not present in everyday food.

Pairs with

Maca, tongkat ali (libido / sexual function combos). L-arginine, L-citrulline (nitric oxide synergy). Zinc, boron (hormonal cofactors).