Tongkat Ali
Eurycoma longifolia
A Southeast Asian root traditionally used as an aphrodisiac and tonic, with small trials suggesting modest improvements in testosterone (mainly in men with low levels), stress hormones, and sexual well-being.
At a Glance
- Best known for
- May raise testosterone in men with low or borderline levels, Reduced cortisol and improved mood under stress in one trial, Supports libido and sexual function
- Evidence
- Preliminary
- Typical dose
- 200–400 mg standardized extract daily
- Type
- Herb
What is Tongkat Ali?
Tongkat ali (Eurycoma longifolia), also called longjack or pasak bumi, is a slender tree native to the rainforests of Malaysia, Indonesia, Thailand, and Vietnam. Its long, bitter taproot has been used in Malay traditional medicine for centuries as an aphrodisiac, energy tonic, and remedy for fever, malaria, and post-partum recovery. Malaysia has supported research on standardized water extracts (such as the Physta/LJ100 extract) since the 1990s, which is why most clinical data come from that country. It is now sold worldwide for testosterone, stress, libido, and athletic performance.
Known Health Benefits
How It Works
Tongkat ali does not contain hormones. Quassinoids such as eurycomanone appear to increase testosterone by stimulating the release of luteinizing hormone from the pituitary and by inhibiting aromatase, the enzyme that converts testosterone to estrogen. Eurypeptides are reported to release testosterone from sex hormone-binding globulin (SHBG), raising the free fraction. The extract lowers cortisol in stressed subjects, suggesting an adaptogen-like effect on the HPA axis. Eurycomanone also inhibits phosphodiesterase and enhances nitric oxide signaling in animal models, consistent with pro-erectile effects. Anti-malarial and cytotoxic quassinoids explain traditional uses but are not the focus of supplements.
What Research Says
Clinical trials are small and mostly from a single research group in Malaysia using the standardized water extract. A 2012 RCT of 109 men found 300 mg daily for 12 weeks improved sexual well-being scores and increased sperm motility and semen volume compared with placebo. A 2013 study of 63 moderately stressed adults found 200 mg daily for 4 weeks lowered salivary cortisol by about 16% and raised testosterone by about 37% versus placebo, with improved mood scores. An open-label study of 76 men with late-onset hypogonadism found 200 mg daily normalized testosterone in most participants after one month. A 2022 systematic review and meta-analysis of randomized trials concluded tongkat ali significantly increased total testosterone, with larger effects in older men and those with low baseline levels, but noted the small number and size of trials. Effects on muscle strength and athletic performance are inconsistent. The evidence is promising but preliminary.
Active Compounds
Quassinoids (eurycomanone, eurycomanol), eurypeptides, canthin-6-one alkaloids, squalene derivatives, biphenylneolignans
Forms & Bioavailability
Eurycomanone is absorbed orally but has low bioavailability (around 10% in animal studies) because of poor membrane permeability and first-pass metabolism; nonetheless hormonal effects are observed in humans at 200–400 mg of extract. Water extracts standardized to quassinoids and eurypeptides are the forms used in trials; generic 'root powder' has far lower active content. Extract ratios like 100:1 describe concentration from raw root, not potency, and do not substitute for standardization.
Dosage Guidance
| Use Case | Dosage |
|---|---|
| Testosterone / vitality support | 200–400 mg standardized extract daily |
| Stress and mood | 200 mg standardized extract daily |
| Male fertility / sperm quality | 200 mg extract daily |
| Sexual function | 300 mg extract daily |
| Root powder (non-standardized) | 1–2 g daily |
Always consult a healthcare provider for personalized dosing.
Natural Food Sources
- Not found in food; the root is used medicinally only
- Added to some Malaysian 'tongkat ali coffee' products (dose unreliable)
Potential Side Effects
Insomnia, restlessness, irritability, increased body temperature; occasional stomach upset; rare reports of elevated heart rate
Who Should Avoid It
- Hormone-sensitive cancers (prostate, breast) or elevated PSA — raises testosterone
- Pregnancy and breastfeeding
- Insomnia or anxiety disorders (stimulating in some people)
- Severe kidney or liver disease (quassinoids are metabolized hepatically; mercury contamination has been found in some unregulated products)
- Concurrent diabetes or blood pressure medication without monitoring
Pregnancy & Lactation
Contraindicated in pregnancy and lactation. Tongkat ali affects reproductive hormones and has no safety data in pregnant or breastfeeding women. Some traditional post-partum tonics contain it, but modern guidance is to avoid it.
Known Drug Interactions
May add to the effects of diabetes drugs (hypoglycemia); may interact with blood pressure medication; theoretical interaction with immunosuppressants and hormone therapies; avoid with propranolol (reduced absorption reported)
Evidence Classification
Based on in vitro studies, animal models, pilot trials, or traditional use documentation. Clinical evidence is limited.
Frequently Asked Questions
Will tongkat ali raise my testosterone?
In trials it raised testosterone most clearly in men whose levels were low or borderline, and in people under stress. In healthy young men with normal levels the effect is smaller and less consistent. It is not a replacement for medical evaluation if you have symptoms of low testosterone, since the cause matters.
Does it work for women?
A few small studies have included women, mostly looking at stress, mood, and energy. The cortisol-lowering effect appeared in both sexes. Because it can raise testosterone, women with PCOS, hirsutism, or hormone-sensitive conditions should be cautious. It is not recommended during pregnancy or breastfeeding.
How do I choose a quality product?
Look for a standardized water extract specifying eurycomanone content (often 0.8–1.5%) and ideally third-party testing, since Malaysian and Indonesian authorities have found heavy metals and adulterants (including sildenafil) in some unregulated products. Extraction ratios such as 200:1 are marketing figures, not a guarantee of potency.
Can I take it with ashwagandha or tribulus?
They are commonly stacked. Ashwagandha is better supported for stress and sleep and tends to be calming, which can offset tongkat ali's stimulating quality. Tribulus has weak evidence for testosterone in humans. There is no trial data on combinations, so start with one, assess, and add cautiously.
References
- Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects. Talbott SM, Talbott JA, George A, Pugh M. J Int Soc Sports Nutr (2013)View study
- Randomized clinical trial on the use of PHYSTA freeze-dried water extract of Eurycoma longifolia for the improvement of quality of life and sexual well-being in men. Ismail SB, Wan Mohammad WM, George A, et al.. Evid Based Complement Alternat Med (2012)View study
- Efficacy of Tongkat Ali (Eurycoma longifolia) on testosterone: a systematic review and meta-analysis of randomised controlled trials. Leitão AE, Vieira MCS, Pelegrini A, et al.. Complement Ther Med (2021)
- Eurycoma longifolia. Examine.comView study
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This entry is for educational purposes only. It is not medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement regimen, especially if you take medications or have health conditions.