Supplement Science

Tongkat Ali Explained: What the Research Says About Eurycoma Longifolia

The cortisol-lowering, libido-supporting Southeast Asian root that's earned a place in modern T formulas.

7 min read · XT Editorial Team · Reviewed & updated

What it is

Tongkat ali (Eurycoma longifolia) is a Southeast Asian root with traditional use for vitality and fertility. Modern standardized extracts target 2% eurycomanone.

What the trials show

Human trials at 200 mg/day of standardized extract show reductions in cortisol, modest increases in total and free testosterone in stressed men, and improvements in subjective libido and well-being.

Dose and safety

200–400 mg/day of standardized extract is the trial-supported dose. Well-tolerated. Effects are modest, additive to a complete formula rather than standalone.

Frequently asked questions

Does tongkat ali work for libido?
Multiple trials show improvements in libido and sexual well-being, especially in older or stressed men.
Is tongkat ali safe?
Standardized extracts are well-tolerated in 12-week trials. Long-term safety data is more limited.
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