Quick answer: Tongkat Ali has small trials showing modest testosterone increases mainly in men with low levels or high stress, at 200 to 400 mg of extract a day. Tribulus does not raise testosterone in healthy men, though a few trials report better desire scores. Neither is a substitute for testing.
Tongkat Ali
Studies are small and often industry-funded. Some products have contained heavy metals, so quality matters. PubMed.
Tribulus
Reviews consistently find no testosterone rise in healthy men. PubMed.
Who should be careful
Men with prostate problems or hormone-sensitive conditions, and anyone on hormone therapy.
Better first step
If you suspect low testosterone, a morning blood test is far more useful than any herb.
More Strong Peak guides
General information, not medical advice. Strong Peak is a dietary supplement and is not intended to diagnose, treat, cure or prevent any disease.