Tongkat Ali
Tongkat ali is Eurycoma longifolia, a Southeast Asian tree whose root extracts are sold as supplements.
Also listed as Longjack, Malaysian Ginseng, Longjax, Cay Ba Binh
Does it raise testosterone?
A 2022 review included nine clinical studies and pooled five randomized trials. Total testosterone increased overall, with a positive result also in men with hypogonadism. This is a promising hormonal finding, but the authors called for further research before clinical use; it does not establish long-term benefit or safety. 1
Small-trial evidence supports a possible increase in total testosterone, particularly with low baseline levels. 1
Does higher testosterone mean better sexual function?
A 2015 meta-analysis of two trials involving 139 participants found no significant overall improvement in erectile-function scores at twelve weeks. A subgroup with poorer starting scores improved. That signal warrants further study; it does not establish a reliable effect for everyone or answer the separate question of libido. 2
Erection-score evidence is limited and does not directly establish increased desire. 2
What did the exercise combination trial show?
A six-month trial in 45 men with age-related androgen-deficiency symptoms studied 200 mg tongkat ali alongside concurrent exercise training. The combined intervention improved erectile function and total testosterone. This small combination study cannot establish the same result for a supplement taken without that training context. 3
Can it help with stress?
A four-week trial in 63 moderately stressed adults used 200 mg/day of a standardized hot-water root extract. Tension, anger and confusion scores improved, but depression, vigor and fatigue did not. The study had manufacturer funding and author industry ties. 4
How might the hormone effects arise?
The stress trial discusses altered testosterone release from its binding protein as a proposed mechanism. The authors state that the precise mechanism is unknown; this hypothesis is not proof of broad “adaptogenic” protection. 4
What is not assessed here?
This page does not evaluate lifespan extension, infertility treatment or benefits in women beyond the mixed-sex stress trial.
Effects by health goal
Open an effect to see the studies behind its rating. Bars show the size of the effect; the letter grades the evidence.
Sexual Health1 effect
Men's Hormones1 effect
Stress & Mood2 effects
Fitness1 effect
No study is linked to this rating.
Cognition1 effect
No study is linked to this rating.
Energy2 effects
No study is linked to this rating.
No study is linked to this rating.
Longevity1 effect
No study is linked to this rating.
All studies
8 publications are linked to Tongkat Ali, newest first.