Tongkat Ali

Is tongkat ali safe?

The root extract itself looks fairly benign in small trials. The products it comes in are the problem. Tongkat ali (Eurycoma longifolia) is a slow-growing tree from Malaysia and Indonesia, and its root is sold mostly to men hoping for more testosterone, energy and libido. Most trials used 200 to 400 mg a day of a standardised water extract for a few weeks to six months and reported few side effects.

Three findings pull the score down. The European Food Safety Authority (EFSA) found a DNA-damage signal and declined to call the extract safe. Malaysian testing found mercury and lead in a large share of products. And "male enhancement" products containing tongkat ali have been caught with hidden prescription drugs.

What did EFSA find?

In 2021 EFSA assessed a standardised water extract proposed for use at up to 200 mg a day by adults. In a lab test the extract damaged chromosomes, and in a follow-up test in rats it caused DNA damage in the stomach and duodenum at the highest dose, 2,000 mg per kg of body weight. EFSA judged this to be genotoxicity rather than simple cell damage, and concluded that the extract's safety "has not been established under any condition of use".

That does not prove tongkat ali causes cancer in people. It means the only full regulatory review of the substance could not rule out a long-term risk, and the extract has not been authorised for sale as a novel food in the EU.

Heavy metals: what the Malaysian tests showed

Malaysia sets a limit of 0.5 ppm mercury for traditional medicines. Researchers there bought 100 tongkat ali products and found 36% above the limit, with up to 5.3 ppm (2004). A second test of 100 "tongkat ali hitam" products found 26% above it (2006). Some failing products were already registered with the national drug authority. A 2003 lead study found 8 of 100 herbal products at 10.6 to 20.7 ppm lead, all of them sold as tongkat ali.

These tests are 20 years old, and registration rules have tightened since. But no large independent test of current products sold online in the US or Europe has been published, so there is no evidence the problem has gone away either.

Hidden Viagra in "male enhancement" products

This is the most immediate risk. FDA's Health Fraud Product Database lists over 600 entries since 2007 for products with undeclared sildenafil, tadalafil or similar drugs, almost all sold for sexual performance, including more than 30 in 2026 alone. Tongkat ali appears on the labels of some of them.

Two US Class I recalls, the most serious kind, named tongkat ali on the label. In 2017 "grande X 5800" capsules contained sildenafil, tadalafil and an unapproved analogue. In 2022 a honey sachet "with caviar and tongkat ali powder" contained tadalafil.

Hidden sildenafil or tadalafil is dangerous for anyone taking nitrates such as nitroglycerin, because the combination can cause a sudden, severe fall in blood pressure. A product that works within an hour like a prescription drug may well contain one.

Does it work?

The evidence is thin. A 2022 meta-analysis pooled five small randomised trials and found a rise in total testosterone, clearest in men with low levels. A 2015 meta-analysis of two erectile function trials (139 men) found no overall benefit. The trials used different proprietary extracts, and none was large. Men with real symptoms of low testosterone should get a blood test; prescription testosterone has its own risks but is at least well studied.

Who should avoid tongkat ali

• Anyone taking nitrates for angina or heart failure, because of the risk of hidden PDE5 inhibitors.
• People with liver disease or heart rhythm problems: LiverToxLiverToxA free US National Institutes of Health database that summarises what is known about liver injury caused by medicines, herbs and supplements.More in the glossary notes liver injuryDrug-induced liver injuryLiver damage caused by a medicine, herbal product or supplement. It is usually rare and unpredictable, but it can be serious.More in the glossary reports in bodybuilders, and a 2025 case report linked it to atrial flutter.
• Men with prostate cancer or other hormone-sensitive conditions, since the product is sold to raise testosterone.
• Pregnant or breastfeeding women, who were excluded from EFSA's assessment.

Talk to your doctor or pharmacist before taking it with regular medicines.

How to lower the risk

1. Buy a single-ingredient extract with a named standardised extract and dose, not a "male enhancement" blend.
2. Ask for a batch test for lead, mercury, arsenic and cadmium, and for PDE5 inhibitors.
3. Avoid sellers promising instant results, and stop if you get palpitations, yellow skin or dark urine.

How we scored it

Quality (35) is the weakest factor, reflecting the mercury and lead findings and Class I recalls for hidden drugs. Regulatory actions (45) reflect EFSA's refusal to call it safe and FDA's long list of adulterated sexual-enhancement products. Dose safety, organ toxicity and interactions (65 each) are moderate: small trials look benign, but liver and heart case reports and the genotoxicity signal keep them well below simple supplements such as creatine.