Simaroubaceae
Tong Kat Ali
Eurycoma longifolia
⚠ Use with Caution
Avoid in Pregnancy
Native to: Malaysia, Indonesia, Thailand, Vietnam
Also known as: Longjack, Malaysian Ginseng, Pasak Bumi, Ali's Umbrella
Wikimedia Commons / CC BY-SA
Parts Used
Root
Therapeutic Uses
Male hypogonadism (testosterone optimization — multiple RCTs), sexual dysfunction and libido, sports performance, male infertility, fatigue. Strongest clinical evidence among testosterone-supporting herbs.
Herbal Actions
Testosterone booster (LH-mediated steroidogenesis + SHBG reduction), adaptogen, antifatigue, aphrodisiac, antimalarial (quassinoids), anti-estrogenic
Active Constituents
Quassinoids (eurycomanone, eurycomalactone, eurycomaoside — primary actives), alkaloids (beta-carboline, canthin-6-ones), biphenylneolignans, steroids
Preparation Methods
💊 Capsule🏺 Tincture🍵 Decoction
Traditional Preparation Notes
| Herbal Tea | 5–10g dried root simmered 30 min in 500ml, 2x daily — very bitter |
| Tincture | Standardized 1:200 extract: 200–400mg daily |
| Notes | 1:200 extract (LJ100 brand): 200mg daily — most studied. Effects in 4–8 weeks. For testosterone: morning dose best (mimics natural diurnal rhythm). Cycling optional but reduces cost. Quality varies enormously — standardized extract essential. |
Safety Information
Safety Rating
⚠ Use with Caution
Pregnancy
Avoid in Pregnancy
Drug Interactions
Possible — consult doctor
Contraindications: Avoid in prostate cancer (raises testosterone). Avoid in hormone-sensitive conditions. Caution with antidiabetics. Avoid in pregnancy.
Side Effects: Insomnia (stimulating). Irritability at high doses. Restlessness. Generally well tolerated at standard doses.