The benefits of Tongkat Ali for athletes: the evidence base

Tongkat Ali, the root of the Southeast Asian plant Eurycoma longifolia, has become a popular herbal supplement among athletes who hope to support testosterone, manage stress and aid recovery. Marketing claims are bold; the research is more measured but not negligible. The editorial team examines what controlled studies actually show, where the evidence is reasonable and where it is thin, with a practical, UK-focused view.

What Tongkat Ali is

Tongkat Ali is a traditional remedy from Malaysia, Indonesia and neighbouring countries, where the root has long been used as a tonic. Its active constituents include compounds called quassinoids, among them eurycomanone, which are thought to underlie its biological effects. Modern supplements are typically standardised extracts, often described by the percentage of key markers.

The plant's reputation centres on male hormonal health and vitality, which is why it has migrated into the sports-supplement market. Unlike anabolic agents, it is a botanical sold as a food supplement, regulated in the UK and EU as such rather than as a medicine.

Standardisation is a genuine issue. Because effects depend on the concentration of active compounds, products vary widely, and much of the better research uses specific, well-characterised extracts that may not match what is on a given shelf. This makes it hard to generalise from a trial to an arbitrary product.

With that caveat, there is a real body of human research — more than for many herbal supplements — which allows a reasonably grounded assessment rather than pure speculation.

Testosterone and hormonal effects

The headline claim is that Tongkat Ali raises testosterone. The evidence is mixed but leans towards a modest effect in specific groups. Several studies in men with low testosterone, or under stress, have reported increases in testosterone and improvements in symptoms, while studies in young, healthy, already-replete men are less consistent.

A frequently cited mechanism is an effect on sex-hormone-binding globulin and on stress hormones, potentially freeing up more usable testosterone rather than dramatically increasing total production. Some trials in older or hypogonadal men have shown meaningful shifts; the picture in elite young athletes is weaker.

The honest reading is that Tongkat Ali is not a substitute for anabolic drugs and will not transform a healthy young athlete's hormones. Where it may help is in restoring or supporting normal levels in men whose testosterone is suppressed by age or stress, which is a more modest but legitimate proposition.

As always, a supplement that nudges hormones within the normal range is different from a drug that pushes them above it, and the two should not be conflated.

Stress, cortisol and recovery

Some of the more interesting findings concern stress rather than testosterone directly. A notable study reported that a standardised extract reduced tension, anger and confusion and lowered cortisol in moderately stressed adults, while nudging testosterone upward. For athletes, the stress axis matters because chronically high cortisol can impair recovery and blunt adaptation.

If Tongkat Ali improves the balance between anabolic and catabolic hormones under stress, the plausible benefit for athletes is better recovery and mood during hard training blocks, rather than a direct boost to strength. This framing fits the data better than the raw "testosterone booster" headline.

Evidence on direct performance outcomes — strength, power, endurance — is more limited and less convincing. A few small trials have hinted at modest improvements in muscular strength or body composition when combined with training, but the studies are small and not always well controlled.

So the recovery-and-stress angle is arguably the better-supported one, though still modest. Athletes should expect a supportive role at most, not a dramatic ergogenic effect.

Safety, quality and regulation

In the doses used in studies, standardised Tongkat Ali extracts appear reasonably well tolerated over the short to medium term, with few serious adverse effects reported. Mild effects such as restlessness or insomnia are occasionally noted, plausibly linked to its stimulating reputation.

Two practical safety issues deserve emphasis. The first is heavy-metal contamination: some products, particularly cheap or poorly sourced ones, have been found to contain excess mercury or other contaminants. Choosing reputable, tested products matters.

• Quality: prefer standardised extracts from reputable manufacturers with contaminant testing.
• Interactions: caution with medicines affecting blood sugar or the immune system; discuss with a pharmacist.
• Who should avoid it: those with hormone-sensitive conditions, and anyone pregnant or breastfeeding, given limited data.
• Anti-doping: as a botanical, it is not on the prohibited list, but supplement contamination is a general risk for tested athletes.

The second issue is the general supplement caveat for competitive athletes: products can be contaminated with undeclared substances, so those subject to anti-doping testing should use batch-tested supplements and remain cautious.

In the UK and EU, Tongkat Ali is sold as a food supplement, which means it is not assessed for efficacy the way a medicine is. That regulatory status is a reminder to keep expectations realistic and to prioritise product quality.

Practical takeaways for athletes

Pulling the evidence together, Tongkat Ali is a plausibly useful but modest supplement, best understood as a support for hormonal balance and stress resilience rather than a performance drug. The men most likely to notice a benefit are those whose testosterone is suppressed by age, stress or heavy training load, not young athletes with already-normal levels.

If you choose to try it, realistic expectations are key. Judge it over a few weeks by how you feel — mood, recovery, libido — rather than expecting measurable jumps in strength. Combine it with the fundamentals that reliably work: adequate sleep, sensible training load, sufficient protein and energy, and stress management.

Do not use it to paper over a genuine problem. Persistent fatigue, low libido or symptoms of low testosterone warrant a proper assessment and blood tests, not an indefinite trial of a herbal supplement. A doctor can distinguish a treatable cause from normal variation.

Readers interested in this area may also enjoy our overviews of adaptogens and stress, of natural ways to support testosterone, and of evidence-based recovery strategies, which place Tongkat Ali in a broader context.

Conclusions of the editorial team

Tongkat Ali has a more substantial human evidence base than many herbal supplements, and it points to a modest, supportive role — mainly in men with suppressed testosterone or elevated stress, where it may improve the hormonal balance and sense of recovery.

It is not an anabolic agent and will not transform a healthy young athlete's physiology. Direct performance benefits are weakly supported at best.

If used, choose a quality-tested, standardised product, keep expectations realistic, and treat it as an adjunct to sleep, nutrition and training rather than a shortcut. For genuine symptoms of low testosterone, see a doctor rather than relying on a supplement.

References

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