Does tongkat ali boost testosterone?
Moderate EvidenceIT DEPENDS
Moderate evidence that tongkat ali (Eurycoma longifolia) modestly increases testosterone in men with low or borderline-low levels, particularly in stressed or aging populations. Effects in young healthy men with normal testosterone are less clear. Quality and standardization of extracts vary significantly.
The Verdict
Moderate evidence that tongkat ali (Eurycoma longifolia) modestly increases testosterone in men with low or borderline-low levels, particularly in stressed or aging populations. Effects in young healthy men with normal testosterone are less clear. Quality and standardization of extracts vary significantly.
What the Evidence Shows
Tongkat ali (Eurycoma longifolia Jack) is a Southeast Asian herb traditionally used as an aphrodisiac and vitality tonic. Its bioactive compounds (eurycomanone, quassinoids) are proposed to increase testosterone via several mechanisms: inhibition of aromatase (reducing testosterone-to-estrogen conversion), stimulation of Leydig cell function, and reduction of sex hormone-binding globulin (SHBG), which increases free testosterone. Clinical trials show the most consistent effects in men with late-onset hypogonadism, high cortisol levels, or aging-related testosterone decline. A 2022 systematic review of 9 RCTs found significant improvements in total testosterone with tongkat ali supplementation, particularly in stressed individuals. However, the research has limitations: many studies use small samples, are conducted by groups with potential conflicts of interest, and use proprietary extracts that may not represent commercially available products. The magnitude of testosterone increase (15-40%) is clinically relevant in borderline-deficient men but unlikely to produce supraphysiological levels in healthy young men.
Evidence Quality
2
Meta-Analyses
9
RCTs
6
Observational
Important Caveats
- ⚠️ Most robust effects seen in men with low or borderline testosterone
- ⚠️ Young healthy men with normal testosterone may see minimal benefit
- ⚠️ Extract quality and eurycomanone content vary widely between products
- ⚠️ Many studies funded by supplement manufacturers or conducted in Malaysia
- ⚠️ Long-term safety data beyond 12 months are limited
- ⚠️ Cannot compare to testosterone replacement therapy in efficacy
Population Studied
Men aged 30-65 with late-onset hypogonadism, stress-related low testosterone, or aging-related decline; some studies in healthy young athletes
Dosage
200-400mg/day of standardized water extract (typically standardized to 1-2% eurycomanone); higher doses not well-studied
Duration
Most clinical trials lasted 4-12 weeks; testosterone changes typically observed by week 4
Supporting Studies (2)
Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects
RCTTalbott SM, Talbott JA, George A, Pugh M. · Journal of the International Society of Sports Nutrition (2013)
In 63 moderately stressed adults, 200mg/day tongkat ali for 4 weeks significantly reduced cortisol (-16%) and increased testosterone (+37%) compared to placebo, with improvements in tension, anger, and confusion.
View paper (DOI) →Eurycoma longifolia Jack in managing idiopathic male infertility
RCTIsmail SB, Wan Mohammad WMZ, George A, et al. · Asian Journal of Andrology (2012)
In 75 men with idiopathic infertility, 200mg/day tongkat ali for 9 months increased sperm concentration, motility, and quality, with 14.7% achieving spontaneous pregnancy (vs 11.7% in untreated infertile couples).
View paper (DOI) →Contradicting Studies (1)
The effects of Eurycoma longifolia supplementation on testosterone and strength in resistance-trained men
RCTHenkel RR, Wang R, Bassett SH, et al. · Journal of the International Society of Sports Nutrition (2014)
In young resistance-trained men (mean age 25) with normal testosterone, 400mg/day tongkat ali for 8 weeks did not significantly increase total or free testosterone compared to placebo, and did not enhance strength gains.
Why this disagrees:
In young healthy men with already-normal testosterone levels and regular training, tongkat ali does not produce meaningful hormonal changes. The supplement appears to be most effective at restoring suboptimal testosterone rather than elevating already-healthy levels, limiting its utility for young athletes.
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