Tongkat Ali (Eurycoma longifolia)

Root extract containing eurycomanone, eurycomanol, and other quassinoids that modulate testosterone through multiple pathways. Inhibits aromatase (CYP19), reducing estrogen conversion. Stimulates CYP17 enzyme activity, increasing DHEA and androstenedione as testosterone precursors. May also reduce SHBG, increasing free testosterone fraction. Anti-cortisol properties via HPA axis modulation provide permissive endocrine environment for testosterone production.

Half-life

~9 hours (estimated from eurycomanone PK)

Bioavailability

~30-40% (oral, estimated)

Route

oral

Evidence tier

T2 — Single-RCT or mechanistic

Optimization pillars

muscle · recovery

References

3 peer-reviewed

Dose ranges

Three tiers ordered by aggressiveness. Tier chips on every OPTIMIZE intervention let you filter the catalog by your evidence tolerance.

conservative

200 mg/day

General hormonal support (standardized extract)

moderate

300–400 mg/day

Testosterone optimization

aggressive

400–600 mg/day

High-dose clinical protocol

Monitoring

total-testosterone
free-testosterone
estradiol
shbg
cortisol
alt
ast

Contraindications

hormone-sensitive-cancer
pregnancy

References

PMID:23243445Review on a traditional herbal medicine, Eurycoma longifolia (Tongkat Ali): its traditional uses, chemistry, evidence-based pharmacology and toxicology — Molecules, 2013
PMID:26365449Eurycoma longifolia (Tongkat Ali) supplementation and its effect on cortisol and testosterone in moderately stressed adults — J Int Soc Sports Nutr, 2013
PMID:34364473Eurycoma longifolia Jack (Tongkat Ali) supplementation on testosterone and body composition in men — Complement Ther Med, 2021

Notes

Tongkat Ali is the natural testosterone compound with the best mechanistic profile. Multiple converging pathways — aromatase inhibition, CYP17 stimulation, SHBG reduction, cortisol suppression — all pointing toward improved free testosterone. The clinical data shows 30-50% increases in total testosterone in hypogonadal or stressed males. That will not replace TRT for someone with primary hypogonadism, but for a stressed 35-year-old with cortisol-mediated suppression, it can move the needle. Extract quality matters enormously. Standardized to eurycomanone content or the supplement is useless.

This is not medical advice

Discuss with a licensed clinician before starting, stopping, or changing any compound. This page documents what the research literature describes — it is not a prescription.

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