Tongkat ali (Eurycoma longifolia, standardised)

Tier 3 — weak evidence · Testosterone · Stress · Men's health

A Southeast Asian herb with evidence for modest testosterone support in men with low-normal levels. A 2024 systematic review of 9 trials found standardised extracts (200–400 mg/day) significantly increased total testosterone and reduced cortisol in stressed adults. Works primarily by reducing SHBG and cortisol rather than directly stimulating testosterone production. Avoid unregulated products — contamination risk is high.

Dose: 200–400 mg/day standardised extract (2% eurycomanone minimum); effects strongest in men with low-normal testosterone