Tongkat Ali

evidence score

supplement

193 studies

Eurycoma longifoliaLongjackMalaysian ginseng+2 more

Tongkat Ali (Eurycoma longifolia) is a Southeast Asian medicinal plant root with evidence for increasing free testosterone in men with suboptimal testosterone levels. Clinical trials (primarily using standardized 200–400mg aqueous root extract) show modest but statistically significant increases in free testosterone (10–40%) in hypogonadal-range men, older men, and those under stress — likely through reduction of SHBG and cortisol-mediated HPG suppression. Does not appear to increase testosterone beyond the normal physiologic range in healthy young men. Human trials also support improvement in male fertility parameters, stress hormone reduction, and muscle strength in resistance-trained subjects. Well-tolerated. Popular "natural" alternative to TRT among men with borderline low testosterone.

Evidence

Moderate evidence

Safety

Unknown safety profile

Clinical Status

Phase II

Research Sync

Feb 19, 2026

Dosing

Typical

200 mg

100 mgRange400 mg

FrequencyOnce daily oral (standardized extract)

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Pharmacology

Half-lifeUnknown (herb extract; multiple active compounds)

Onset2–4 weeks for hormonal effects; benefits accumulate over 8+ weeks

DurationEffects likely require continued supplementation to maintain

Routes

oral

Evidence Score

Level B — Moderate

193 studies indexed · 1 meta-analysis

Scoring Factors

Volume(40%)~46/100

Quality(30%)~44/100

Sample Size(10%)~100/100

Consistency(10%)~100/100

Replication(5%)~100/100

Recency(5%)~100/100

Scores estimated from study counts. Exact breakdown computed after research sync.

Evidence Levels

AScore ≥75 with at least 1 meta-analysis and 3+ RCTs

BScore ≥50 with at least 1 RCT or meta-analysis

CScore ≥25 — observational or animal evidence only

DScore <25 — very limited or preclinical data

Plain-English Snapshot

Tongkat Ali is currently categorized as a supplement compound.

Evidence is moderate (68/100): promising signal from 193 indexed studies, but context and population still matter.

Safety scoring is incomplete. Start conservatively and monitor carefully.

Core mechanism

Reduces SHBG and cortisol to free more testosterone; possible direct LH/FSH stimulation; eurycomanone (active quassinoid) drives most studied effects

Practical Context

Strongest current signals

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