Men's Health · Supplement Guide
Tongkat Ali in Thailand
What tongkat ali is, what the evidence actually shows for testosterone and energy, and why the source of a product matters more than the label. Reviewed by a licensed physician at a MOPH-registered men's health clinic.
- Sold as a supplement in Thailand
- Evidence is modest and mixed
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Medically reviewed by Dr. Noppon Arunkajohnsak (Win)
Menscape Clinic
Last reviewed
11 July 2026
37%
Testosterone in one trial
small 4-week study, stressed adults
200–400
Daily dose in studies
milligrams of standardized extract
4–12
Weeks in most trials
short studies, small samples
Supplement
Not a registered medicine
sold as a dietary supplement here
Key takeaways
Tongkat ali (Eurycoma longifolia) is a Southeast Asian herbal supplement, not a registered medicine and not a testosterone treatment.
The evidence is modest: small, short trials suggest possible gains in testosterone, mood and energy in some men, but results are mixed and not proven in large independent studies.
The real danger is quality. Grey-market products are repeatedly found spiked with undeclared drugs or contaminated with heavy metals such as mercury.
If you have symptoms of low testosterone or persistent fatigue, get assessed by a doctor first. A supplement is no substitute for a proper diagnosis.
01
What tongkat ali is & how it may work
Tongkat ali is the root extract of Eurycoma longifolia, a shrub native to the forests of Southeast Asia, including Thailand, where it is known as pla-lai-phueak. It has a long history in traditional medicine and is sold today as a dietary supplement, not a licensed medicine.
The most-studied preparations are standardized water extracts of the root, rich in compounds called quassinoids such as eurycomanone. Laboratory work suggests these may influence how the body handles the stress hormone cortisol and how much testosterone circulates in an active, free form. That is the proposed basis for the effects reported in some small trials.
It is worth being clear about what tongkat ali is not. It is not testosterone-replacement therapy, and it is not a treatment for erectile dysfunction or any diagnosed condition. If you have symptoms of low testosterone, those symptoms deserve a proper medical work-up before you reach for a supplement.
Root extract
The supplement is made from the root of Eurycoma longifolia, ideally standardized to its active quassinoids.
May lower cortisol
A small study reported a modest drop in the stress hormone cortisol in moderately stressed adults.¹
May free up testosterone
By influencing binding proteins, it is proposed to raise free testosterone, though the data are limited and mixed.⁴
Effects build slowly
Any reported changes appear over several weeks of daily use, not after a single dose.
02
Getting tongkat ali in Thailand
Thai regulatory status
In Thailand tongkat ali is regulated as a dietary supplement and traditional remedy, not as a drug. It is native here and sold widely, sometimes under brands such as Tongkat Ali or Longjack. Supplement registration does not test whether a product works or verify its dose.⁶
How to get it through Menscape
Menscape does not treat tongkat ali as a shelf medicine. If a doctor agrees that a trial of a standardized supplement is reasonable for you, a quality-verified product can be sourced on request after your consultation, alongside a proper assessment rather than instead of one.
The grey-market problem
The bigger risk is quality. Regulators across the region have repeatedly found tongkat ali products spiked with undeclared drugs, including erectile-dysfunction medicines and steroids, or contaminated with heavy metals such as mercury. Buying from unverified online sellers is where men get hurt.⁵ ⁷
Thai FDA note. A supplement (อย.) registration number confirms a product is legally sold as a dietary supplement. It does not verify the active dose, and marketing claims on the packaging are not approved medical claims.
03
Does it work? The evidence
The honest answer is: possibly, modestly, for some men, and the evidence is not strong. The most-cited trial gave a standardized extract at 200 mg a day to moderately stressed adults for four weeks. It reported a 16% fall in cortisol and a 37% rise in testosterone, along with better tension and mood scores. But the sample was small and the study was industry-funded.¹
Other small trials and reviews report mixed results for libido, energy and body composition, and they share the same limitations: few participants, short durations, different extracts and doses, and heavy reliance on manufacturer funding. There is no large, independent, long-term trial. Treat any single headline number, including the ones above, with caution.² ³
37%
Testosterone, one trial
200 mg/day for 4 weeks, small sample
16%
Cortisol, same trial
self-reported stress also improved
Talbott et al. 2013, a small industry-funded study in moderately stressed adults. Results have not been confirmed in large independent trials. Individual results vary.
04
Side effects & who shouldn't take it
Usually mild
In trials the standardized extract was generally well tolerated. Reported effects include restlessness, difficulty sleeping if taken late in the day, irritability and mild digestive upset.
The adulteration risk
The most serious harms come not from the herb but from contaminated products: undeclared pharmaceuticals, steroids or heavy metals. This is why where you buy it matters more than what the label promises.⁵
Not suitable for
It is for adult men only. Avoid it if you have a hormone-sensitive condition or prostate concerns, liver or kidney disease, or if you are already on hormone therapy. Anyone with a serious medical condition should not self-treat with it.
Interactions & cautions
It may interact with medicines for blood pressure, blood sugar and hormones, and with blood thinners. Tell your doctor everything you take. Stop and seek care if you notice yellowing skin, dark urine or chest symptoms.
05
Alternatives & combinations
Medical · if T is truly low
Testosterone therapy
If blood tests confirm low testosterone alongside symptoms, medically supervised testosterone therapy is the evidence-based treatment, not a supplement. It starts with a proper diagnosis.
Supplement · some evidence
Ashwagandha
Another adaptogenic herb with small studies on stress and testosterone. Like tongkat ali, the evidence is modest and product quality varies widely.
Foundations · free
Sleep, training & weight
Resistance training, better sleep and losing excess weight have clearer, better-proven effects on testosterone and energy than any supplement.
06
How to get it at Menscape
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Talk to a doctor before you self-treat.
Online symptom check
Tell us what you are hoping to improve: energy, libido, mood or low-testosterone symptoms. Five minutes on your phone, and it is PDPA-protected.
Doctor consultation
A licensed Thai physician reviews your symptoms by video call or in clinic at Asoke and, where useful, arranges blood tests to see what is actually going on.
Honest recommendation
If a standardized supplement is reasonable, a quality-verified product can be sourced. If your symptoms point to something treatable, the doctor will say so.
Follow-up
Check-ins to see whether anything changed, and to reassess if a proper medical treatment would serve you better.
The doctor decides. A consultation is not a purchase. Tongkat ali is a supplement, not a cure, and it is not a substitute for diagnosing and treating low testosterone.
Medically reviewed by
Dr. Noppon Arunkajohnsak (Win)
Menscape Clinic, Bangkok
“When men ask me about tongkat ali, there are usually real symptoms behind the question. A simple blood test tells us far more than any supplement label, and it points us to what will actually help.”
- Reviewed
- 11 July 2026
- Next review
- January 2027
- Editorial standard
- Each guide is checked against the Thai FDA label and the primary literature, then reviewed by a licensed physician.
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Frequently asked questions
Can I buy tongkat ali over the counter in Thailand?
Yes. It is sold as a dietary supplement and traditional remedy, so no prescription is needed. The catch is quality: supplement registration does not verify the dose or purity, and adulterated products are common.
Does tongkat ali actually raise testosterone?
In a few small, short trials it produced modest rises in testosterone, mostly in stressed or older men with lower baseline levels. The evidence is limited and mixed, and it is not a replacement for medically supervised testosterone therapy.
Is tongkat ali safe?
The herb itself was generally well tolerated in trials, with occasional restlessness or trouble sleeping. The real safety issue is contamination, with products spiked with drugs or heavy metals, which is why the source matters so much.
How long does it take to work?
Studies ran for four to twelve weeks, so any effect builds over weeks of daily use rather than from a single dose. If nothing has changed after a couple of months, it probably will not.
Can it help erectile dysfunction?
Tongkat ali is not a treatment for erectile dysfunction. ED can be an early sign of heart, hormone or vascular problems, so it should be assessed by a doctor rather than self-treated with a supplement.
Will it affect a drug test or matter for athletes?
The herb itself is not banned, but adulterated tongkat ali products have caused athletes to fail tests for steroids and stimulants. Competitive athletes should be especially careful about the source.
Can I take it with my other medications?
Check with a doctor first. It may interact with blood pressure, blood sugar, hormone and blood-thinning medicines, and hidden ingredients in some products make interactions unpredictable.
What should I look for in a good product?
A standardized root extract with a stated eurycomanone content, third-party testing for contaminants, and a reputable manufacturer. If a product promises dramatic, drug-like results, treat that as a warning sign, not a selling point.
08
References
1. Talbott SM, et al. Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects. J Int Soc Sports Nutr. 2013;10:28.
2. Kotirum S, et al. Efficacy of Tongkat Ali (Eurycoma longifolia) on erectile function improvement: systematic review and meta-analysis of RCTs. Complement Ther Med. 2015;23(5):693-698.
3. Rehman SU, Choe K, Yoo HH. Review on Eurycoma longifolia Jack (Tongkat Ali): traditional uses, chemistry, evidence-based pharmacology and toxicology. Molecules. 2016;21(3):331.
4. George A, Henkel R. Phytoandrogenic properties of Eurycoma longifolia as natural alternative to testosterone replacement therapy. Andrologia. 2014;46(7):708-721.
5. Ang HH, Lee KL. Contamination of heavy metals in tongkat ali herbal preparations. Food Chem Toxicol. 2004.
6. Thai Food and Drug Administration (อย.). Dietary supplement registration and consumer warnings on adulterated products, oryor.com. Accessed July 2026.
7. U.S. FDA. Tainted sexual enhancement products: public notifications database. Accessed July 2026.
This guide is educational information, not medical advice. Tongkat ali is a dietary supplement, not a registered medicine, and it is not a treatment for low testosterone or any diagnosed condition. Speak to a licensed doctor before starting any supplement.
This guide is part of the Menscape longevity library
Explore the condition hubThink your testosterone is low? Get it tested, not guessed.
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