What Is Tongkat Ali?
Tongkat ali is the common name for Eurycoma longifolia, a flowering shrub native to parts of Southeast Asia. It is also called longjack or Malaysian ginseng, although it is not the same plant as true ginseng. The root has a history of traditional use, including in preparations associated with vitality and sexual health. Traditional use can help explain why a plant attracts research, but it is not proof that a supplement safely treats a medical condition.
Today, products are sold as root powder, capsules, tablets, and liquid extracts. These products are not necessarily interchangeable: plant source, extraction method, concentration, and manufacturing quality can differ. A label's “extract ratio,” such as 100:1, does not by itself prove potency, purity, absorption, or clinical effectiveness.
How Tongkat Ali May Work
Researchers have investigated compounds in Eurycoma longifolia, including quassinoids such as eurycomanone, for possible biological activity. Proposed effects involve reproductive-hormone signaling and the body's response to stress, but the mechanisms and their importance in people are not settled. Findings from cells or animals cannot establish that a commercial supplement produces the same effect in humans.
It is also important not to treat cortisol as a simple “bad” hormone. Cortisol has normal roles in metabolism, immune function, and the stress response. Lowering a measured cortisol value is not automatically a health benefit, and a change in one hormone does not guarantee improvements in mood, muscle growth, or performance.
Tongkat Ali and Testosterone: What Human Research Shows
A 2022 systematic review and meta-analysis included nine studies in its qualitative review and five randomized controlled trials in its meta-analysis. The authors reported an increase in total testosterone with Eurycoma longifolia, including in a subgroup of men with hypogonadism, but they also concluded that more research was needed before the supplement could be recommended in clinical practice (Leisegang et al., 2022). The small number of trials, differences between study designs and extracts, and limitations in the underlying evidence mean the result should not be interpreted as proof that every product raises testosterone or that the change improves health.
A separate systematic review of marketed testosterone boosters found that most ingredients lacked convincing evidence of raising total testosterone. It classified Eurycoma longifolia as possibly effective in some populations, rather than definitively effective (Morgado et al., 2024). Taken together, the literature supports cautious interest not a promise of a clinically meaningful hormone increase.
Total testosterone versus free testosterone
Total testosterone measures testosterone circulating in the blood, including hormone bound to proteins and the unbound fraction. Free testosterone is the unbound fraction. These measurements are not interchangeable, and test timing, laboratory method, and a person's health can affect interpretation. Symptoms alone cannot confirm low testosterone. Clinical diagnosis generally requires compatible symptoms or signs and consistently low levels measured with appropriate testing; anyone concerned about low testosterone should discuss evaluation with a qualified clinician rather than using a supplement as a diagnostic trial.
What one stress study found and what it did not prove
In a 2013 randomized study, 63 adults described as moderately stressed (32 men and 31 women) received a standardized hot-water root extract or placebo for four weeks. The researchers reported changes in selected mood scores, a 16% reduction in cortisol exposure, and a 37% increase in salivary testosterone status in the tongkat ali group relative to placebo (Talbott et al., 2013). These are findings from one small, short study using a particular extract; they should not be presented as expected results for all users, as proof of a comparable rise in blood testosterone, or as evidence that tongkat ali treats a stress-related or hormonal disorder.
Possible Benefits Beyond Testosterone
Libido and sexual health
Some small studies have explored sexual desire and related outcomes, but the evidence is not strong enough to say tongkat ali reliably treats erectile dysfunction, infertility, or other sexual-health conditions. Sexual symptoms can have many causes, including medication effects, cardiovascular disease, relationship factors, and hormonal conditions. Persistent concerns deserve an appropriate medical assessment.
Stress, mood, energy, and fatigue
The small trial described above reported improvements in some self-reported mood measures, but it does not establish tongkat ali as a treatment for anxiety, depression, chronic fatigue, or sleep problems (Talbott et al., 2013). Evidence for lasting improvements in everyday energy remains limited. Unexplained or persistent fatigue should be evaluated rather than masked with supplements.
Strength, muscle growth, fat loss, and exercise performance
There is not enough high-quality evidence to recommend tongkat ali as a muscle-building, fat-loss, or performance supplement. A possible change in testosterone does not automatically translate into greater strength, hypertrophy, endurance, or faster recovery. Training progression, sufficient energy and protein intake, sleep, and recovery practices remain more dependable foundations for fitness. Athletes should also consider the risk that a supplement may contain undeclared ingredients.
What about tongkat ali for women?
Much of the testosterone-focused research has involved men, and evidence about benefits and safety in women is limited. Marketing claims about libido, energy, or menopausal symptoms should not be mistaken for established clinical outcomes. People who are pregnant or breastfeeding should not use tongkat ali because adequate safety data are lacking; anyone considering it should consult a healthcare professional, especially if they have a medical condition or take medication.
Dosage: Is There a Recommended Amount?
There is no universally established, evidence-based dose of tongkat ali that can be recommended for general use. Research has tested particular preparations at specific doses and durations, but those results cannot automatically be transferred to products with different extracts, concentrations, or quality controls. A milligram amount alone does not tell you how much of a particular compound is present or whether a product matches the preparation studied.
Do not assume that a higher dose works better, and do not use a study dose as personal medical advice. Cycling schedules—such as taking the supplement for several days and then stopping—have not been established as necessary or as a way to make it safer. If a clinician and you decide to consider a supplement, review the exact product and label together and agree on how to monitor for unwanted effects.
Side Effects and Safety Concerns
Reliable information about the frequency of tongkat ali side effects and its long-term safety is limited. Reports and product guidance commonly raise concerns such as restlessness, irritability, sleep disturbance, or digestive discomfort, but the available evidence does not establish how often these occur or which products are responsible. Stop taking a product if you develop concerning symptoms and seek medical advice when appropriate.
More importantly, the European Food Safety Authority's expert panel concluded that the safety of a proposed Eurycoma longifolia root extract as a novel food had not been established, citing unresolved concerns including genotoxicity data (EFSA NDA Panel, 2021). This assessment concerned a particular proposed extract and regulatory application; it does not prove that every preparation has identical risks. It does, however, make blanket claims that tongkat ali is “proven safe” inappropriate.
Who should be especially cautious?
- People who are pregnant or breastfeeding, and children or adolescents: safety has not been adequately established.
- People with hormone-sensitive conditions or a history of hormone-dependent cancer: consult the treating clinician before considering a product with possible hormonal effects.
- People with liver, kidney, cardiovascular, or psychiatric conditions: discuss potential risks with a clinician before use, because condition-specific safety data are inadequate.
- People taking prescription medicines or other supplements: ask a pharmacist or clinician to review possible interactions. Specific interaction risks for tongkat ali are not well characterized, so do not assume that an interaction is impossible.
Seek urgent medical care for severe symptoms such as difficulty breathing, facial or throat swelling, chest pain, or fainting. For less severe but persistent effects—such as insomnia, palpitations, marked irritability, or digestive problems—stop the supplement and contact a healthcare professional.
How to Evaluate a Tongkat Ali Supplement
No label can guarantee a supplement will work, but transparent quality information can help you avoid some preventable risks. In the United States, the FDA does not approve dietary supplements for safety and effectiveness before they are marketed; manufacturers are responsible for compliance, and FDA action generally occurs after products reach the market (U.S. Food and Drug Administration, n.d.). Products sold online may differ from those used in published studies (National Center for Complementary and Integrative Health, n.d.).
- Look for the exact botanical name. The label should identify Eurycoma longifolia, not only a vague proprietary blend.
- Check the amount per serving and the extract description. An extract ratio or “standardized” label alone does not prove effectiveness or quality.
- Look for independent testing. Prefer a current, product-specific certificate of analysis from a qualified independent laboratory that covers identity and relevant contaminants. Verify that the document matches the product and batch; a brand's general statement that it is “lab tested” is less informative.
- Avoid exaggerated claims. Promises to cure erectile dysfunction, infertility, low testosterone, or rapidly increase muscle mass are red flags.
- Do not substitute supplements for diagnosis or treatment. A product's availability for sale does not establish that it is safe, effective, or appropriate for you.
Third-party testing can reduce uncertainty about identity or contamination when the testing is relevant and credible, but it does not prove a product improves testosterone or athletic performance.
Tongkat Ali vs. Ashwagandha
Tongkat ali and ashwagandha are different botanicals with different research histories. Both are marketed for stress, vitality, and hormone-related outcomes, but it is misleading to label either one a proven testosterone booster or to assume they can be safely combined. Evidence for one herb cannot be used to substantiate claims about the other. If you take medication or have a health condition, review each ingredient separately with a healthcare professional.
Frequently Asked Questions
Does tongkat ali increase testosterone in healthy men?
It may increase total testosterone in some study populations, but the evidence remains limited and does not guarantee a meaningful increase in healthy men. A 2022 meta-analysis reported a positive overall effect while emphasizing the need for more research (Leisegang et al., 2022).
How long does tongkat ali take to work?
There is no reliable timeline that applies across products and users. One four-week trial reported changes in selected mood and salivary hormone measures, but it cannot establish when an individual will notice benefits or whether benefits will occur at all (Talbott et al., 2013).
Can tongkat ali help with bodybuilding or fat loss?
Evidence is insufficient to recommend it for muscle gain, fat loss, or better athletic performance. It should not replace a well-designed training plan, appropriate nutrition, or adequate sleep.
Is tongkat ali safe?
Its safety profile is not fully established, especially for long-term use and for particular extracts. EFSA could not establish the safety of a proposed root extract as a novel food, so claims that the supplement is universally safe are not justified (EFSA NDA Panel, 2021).
Should I take tongkat ali in the morning or before a workout?
No high-quality evidence establishes an ideal time of day or shows that taking it before a workout improves performance. If a product causes restlessness or sleep problems, stop using it and seek advice rather than simply adjusting the timing.
Conclusion
Tongkat ali has a plausible research rationale and some encouraging but preliminary human findings, particularly for testosterone-related outcomes. The available studies are too limited to support broad promises about hormones, libido, stress, muscle growth, or fat loss, and safety uncertainties should not be minimized. If you are concerned about low testosterone or persistent symptoms, seek a proper medical evaluation. If you are considering a supplement, assess its evidence, quality controls, and risks rather than relying on marketing claims.
References
- Leisegang, K., Finelli, R., Sikka, S. C., & Selvam, M. K. P. (2022). Eurycoma longifolia (Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis of Clinical Trials. Medicina, 58(8), 1047. https://doi.org/10.3390/medicina58081047. (PubMed record and abstract reviewed.)
- Talbott, S. M., Talbott, J. A., George, A., & Pugh, M. (2013). Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects. Journal of the International Society of Sports Nutrition, 10, 28. https://doi.org/10.1186/1550-2783-10-28. (Full open-access article reviewed.)
- Morgado, A., Tsampoukas, G., Sokolakis, I., Schoentgen, N., Urkmez, A., & Sarikaya, S. (2024; first published online 2023). Do “testosterone boosters” really increase serum total testosterone? A systematic review. International Journal of Impotence Research, 36, 348–364. https://doi.org/10.1038/s41443-023-00763-9. (Publisher abstract and bibliographic record reviewed; full text is subscription access.)
- EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA). (2021). Safety of Eurycoma longifolia (Tongkat Ali) root extract as a novel food pursuant to Regulation (EU) 2015/2283. EFSA Journal, 19(12), e06937. https://doi.org/10.2903/j.efsa.2021.6937. (Abstract and bibliographic record reviewed; full text was not accessible in the browser during this review.)
- National Center for Complementary and Integrative Health. (n.d.). Dietary and Herbal Supplements. (Institutional guidance page reviewed.)
- U.S. Food and Drug Administration. (n.d.). Information for Consumers on Using Dietary Supplements. (Institutional guidance page reviewed.)
