Tongkat Ali: What the Research Actually Says

Tongkat Ali is one of the most searched, most debated, and most misunderstood ingredients in the men's supplement space. Depending on where you read about it, it's either a natural testosterone miracle or an overhyped herb that does nothing.

The truth, as it usually does, sits somewhere in the middle. And if you're considering a supplement that contains Tongkat Ali, you deserve to see the research rather than the marketing.

Here's what the clinical evidence actually shows.

What Tongkat Ali is

Tongkat Ali (Eurycoma longifolia) is a plant native to Southeast Asia, primarily Malaysia, Indonesia, and Thailand. Its root has been used in traditional medicine for centuries, historically for fevers, infections, and as a general tonic. In recent decades, it's become one of the most popular ingredients in men's health supplements, primarily marketed for testosterone support, libido, and energy.

It goes by several names. Longjack. Malaysian Ginseng. Pasak Bumi. If you've browsed the men's supplement aisle, you've almost certainly seen it.

The testosterone evidence

The most discussed claim about Tongkat Ali is that it raises testosterone levels. And there is evidence to support this, but with important caveats.

A 2022 systematic review and meta-analysis published in Medicina, which analysed five randomised controlled trials, found a significant improvement in total testosterone levels in men supplemented with Eurycoma longifolia. The effect was observed in both healthy volunteers and men with clinically low testosterone. [1]

A separate 2013 study published in the Journal of the International Society of Sports Nutrition found that 200mg per day of standardised Tongkat Ali extract for four weeks produced a 37% increase in salivary testosterone alongside a 16% decrease in cortisol in moderately stressed subjects. [2]

And a 2021 six-month randomised, double-blind, placebo-controlled trial found that Tongkat Ali increased testosterone levels in approximately 50% of study participants and significantly improved erectile function scores, particularly when combined with concurrent exercise training. [3]

These are real findings from published, peer-reviewed research. They're worth taking seriously.

But here's the nuance the marketing usually leaves out.

What the marketing doesn't tell you

The studies are small. The 2022 meta-analysis pooled only five RCTs. The 2013 cortisol study had 63 participants. The 2021 trial had 45. These are promising results, but they're not the kind of large-scale, replicated evidence base that would support the absolute claims many brands make.

An earlier meta-analysis from 2015, published in Complementary Therapies in Medicine, looked specifically at Tongkat Ali's effect on erectile function. It found only two relevant studies totalling 139 participants, and the pooled result showed no significant between-group difference at 12 weeks. A subgroup of men with lower baseline scores did show improvement, but the authors concluded that more trials were needed. [4]

The doses used in the positive studies (typically 200mg to 400mg of standardised extract) don't always match what's in commercial supplements. Many products include Tongkat Ali at lower doses or use non-standardised extracts, which makes it difficult to extrapolate results from clinical research to what you're actually swallowing.

And the quality of the extract matters enormously. Standardised hot-water extracts used in clinical trials are not the same as the generic Tongkat Ali powder you might find in a cheap Amazon blend.

The side effects conversation

Tongkat Ali is generally well tolerated in clinical studies at standard doses (200mg to 400mg daily). But the conversation online, particularly on Reddit and supplement forums, tells a messier story.

Commonly reported side effects include insomnia, restlessness, irritability, and anxiety. These appear to be more frequent at higher doses (above 400mg) and in individuals who are sensitive to stimulant-like effects. Tongkat Ali contains alkaloids that may trigger these reactions in some people. [5]

A 2021 report by the European Food Safety Authority flagged that high doses (2,000mg per kilogram of body weight) of water-based Tongkat Ali extract may lead to DNA damage in stomach and duodenal tissue. The panel concluded that the safety of the ingredient at any condition of use had not been fully established. [5] This is at doses far beyond what any supplement provides, but it's worth knowing the regulatory picture isn't entirely settled.

The practical takeaway: at 80mg to 200mg daily as part of a broader formula, the side effect profile appears to be mild and manageable for most men. But if you're someone who reacts strongly to caffeine, stimulants, or adaptogens, Tongkat Ali is worth introducing gradually rather than starting at a high dose.

What this means for choosing a supplement

If you're evaluating a supplement that contains Tongkat Ali, here's what to look for based on what the research actually supports:

Dose matters. The positive studies used 200mg to 400mg of standardised extract. If a product lists Tongkat Ali without telling you the dose, you have no way of knowing whether you're getting a clinically relevant amount or a trace.

Standardisation matters. Look for standardised hot-water root extracts rather than generic powder. The clinical results come from specific extraction methods, not from ground root in a capsule.

Context matters. The strongest results in the research come from Tongkat Ali used alongside exercise and as part of a daily routine over weeks and months, not as a one-off dose. The 2021 trial that showed the best results combined Tongkat Ali with concurrent training over six months.

Honesty matters. Any brand that tells you Tongkat Ali will "boost your testosterone by 300%" or "work like natural Viagra" is extrapolating well beyond what the published evidence supports. The research is promising but not conclusive. A good brand will tell you that.

References

[1] Leisegang K, Finelli R, Engel KM, et al. Eurycoma longifolia (Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis of Clinical Trials. Medicina. 2022;58(8):1047. PMC9415500.

[2] Talbott SM, Talbott JA, George A, Pugh M. Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects. Journal of the International Society of Sports Nutrition. 2013;10:28. PMC3669033.

[3] Leitão AE, de Souza Vieira MC, Pelegrini A, da Silva EL, de Azevedo Guimarães AC. A 6-month, double-blind, placebo-controlled, randomized trial to evaluate the effect of Eurycoma longifolia (Tongkat Ali) and concurrent training on erectile function and testosterone levels in androgen deficiency of aging males (ADAM). Maturitas. 2021;145:78-85. PMID: 33541567.

[4] Kotirum S, Ismail SB, Chaiyakunapruk N. Efficacy of Tongkat Ali (Eurycoma longifolia) on erectile function improvement: systematic review and meta-analysis of randomized controlled trials. Complementary Therapies in Medicine. 2015;23(5):693-698. PMID: 26365449.

[5] European Food Safety Authority Panel on Nutrition, Novel Foods and Food Allergens. Safety of Eurycoma longifolia (Tongkat Ali) root extract as a novel food. EFSA Journal. 2021;19(12):6937.

Talon includes Tongkat Ali at 80mg per daily serving as part of an 11-ingredient formula. We chose this dose because it performed consistently in our testing without the side effects reported at higher levels. Full doses listed on the bottle.