Tongkat Ali (Eurycoma Longifolia)

The verdict

Is Tongkat Ali worth taking?

Tongkat Ali is the best-evidenced testosterone-supporting botanical in this entire category, which is worth saying clearly before adding that the effect is still modest and population-dependent. The most consistent signal is in men over 40 with low-normal or deficient testosterone, where multiple RCTs show 15 to 37% increases in total testosterone. Effects in healthy young men with normal testosterone are significantly smaller and less consistent. The mechanism appears to operate through cortisol reduction and SHBG modulation rather than directly stimulating new testosterone production. LJ100 and Physta are the standardized extracts behind most of the supporting research.

What it does

What Tongkat Ali does in the body

Testosterone optimization through cortisol modulation, SHBG reduction, and possible direct LH stimulation. Eurycoma longifolia is a Southeast Asian tree whose root extract contains quassinoids, particularly eurycomanone, which modulate the HPA stress axis and appear to reduce the cortisol suppression of testosterone production. A 2025 6-month RCT in men with androgen deficiency of aging confirmed that Tongkat Ali combined with concurrent training improved erectile function and increased total testosterone significantly versus training alone.

The evidence

What the research actually shows

Moderate. A 2022 systematic review and meta-analysis confirmed Tongkat Ali improves serum total testosterone in men. A 2024 analysis of testosterone-booster supplements ranked Tongkat Ali among the best-supported natural testosterone modulators. Nine published RCTs show testosterone increases ranging from 5% to 61%, with effects consistently more pronounced in men with low or borderline baseline levels. One published case of Tongkat Ali- induced liver injury (2024, Cureus) reinforces the value of baseline liver function testing before extended use.

Food first

Getting Tongkat Ali from food

No meaningful food-form equivalent. The food-first approach to cortisol-mediated testosterone suppression is sleep optimization, stress management, resistance training, adequate dietary fat (cholesterol is the precursor to all steroid hormones), and maintaining healthy body fat. These address the hormonal environment more fundamentally than any supplement.

What the guide adds

The part that is not on this page

Everything above is the assessment. What the guide adds for Tongkat Ali is the protocol:

• Optimal Form
• Dose Range
• Bioavailability
• Purity Red Flags
• Stack With / Avoid

147 entries across nine categories, every one graded against the clinical literature the same way.

Get The Complete Supplement Guide →

About the author

Who graded this

Daniel Edlund is a Le Cordon Bleu-trained private chef in Los Angeles, a certified personal trainer and strength coach, and an internationally licensed massage therapist. Thirty years of strength training and fifteen years cooking in private estate kitchens. He is the author of The Complete Supplement Guide, which grades 147 entries against the clinical literature, and of The EASY Way to Organic Cooking, first published in 2013.

More about Daniel →

This page is information, not medical advice. Supplements interact with prescription medication and with each other, and the right answer depends on your own bloodwork and history. Talk to your doctor before starting anything, particularly if you are pregnant, nursing, managing a health condition, or already taking medication.

Also in Hormonal Support & Vitality

Related entries

• DHEA (Dehydroepiandrosterone) — Moderate evidence
• Pregnenolone — Emerging evidence
• Myo-Inositol / D-Chiro-Inositol — Moderate evidence
• DIM (Diindolylmethane) — Moderate evidence

All 147 entries, graded →