Tongkat Ali (Eurycoma longifolia): Benefits, Evidence and Safety

Tongkat ali, or Eurycoma longifolia, is a Southeast Asian plant traditionally used as a male sexual tonic.

Some clinical studies suggest that standardized extracts may increase total testosterone in certain men and may have modest effects on sexual function. The evidence base is still small. Safety is also uncertain: European regulators found potential genotoxicity in one standardized extract and concluded that its safety had not been established.

What is tongkat ali?

Eurycoma longifolia is a small tree native to Southeast Asia.

The root is the part most often used in traditional and commercial preparations.

Products are sold as capsules, tablets, root powders, and standardized extracts.

What is tongkat ali traditionally used for?

Traditional uses include low libido, erectile problems, fatigue, fever, and general strength.

Modern supplements often emphasize testosterone and sports performance.

What does research show?

Testosterone

Meta-analyses suggest that tongkat-ali supplementation may increase total testosterone in some men, particularly those with low levels.

The studies are relatively small and use different extracts.

A laboratory testosterone increase does not automatically mean improved symptoms or long-term health outcomes.

Erectile function and libido

Meta-analysis of a small number of randomized trials has not shown a consistent overall improvement in erectile function, although some subgroups may benefit.

Tongkat ali should not be presented as equivalent to established erectile-dysfunction therapies.

Male fertility and exercise claims

Small studies have investigated semen parameters, stress, body composition, and exercise.

The evidence is not consistent or extensive enough to establish tongkat ali as a treatment for male infertility or a proven muscle-building supplement.

How is tongkat ali used?

Commercial products differ greatly in extract method, concentration, eurycomanone content, and daily amount.

Results from one standardized extract should not be applied automatically to another product.

Is there a standard dose?

No universal evidence-based dose has been established.

A proposed dose evaluated by a regulator should not be repeated as a general recommendation if safety was not established.

What are the side effects and safety concerns?

Short clinical studies have not identified a consistent severe side-effect pattern, but the safety database is limited.

Genotoxicity concern

European regulators identified DNA-damage concerns with one standardized water extract of tongkat-ali root.

This does not prove that every tongkat-ali product causes cancer or DNA damage in people, but it is a meaningful safety signal.

Does tongkat ali interact with medicines?

Clinical interaction studies are limited.

Extra caution is appropriate for people taking testosterone or other hormone therapy, blood-pressure medicines, diabetes medicines, or multiple supplements or prescriptions.

Who should avoid tongkat ali?

Medicinal supplementation deserves particular caution in pregnant or breastfeeding people, children, people with hormone-sensitive conditions, people taking testosterone or fertility medicines, and people with serious chronic disease.

Frequently asked questions

Does tongkat ali raise testosterone?

It may increase total testosterone in some men, particularly those with low levels, but more and better trials are needed.

Does tongkat ali cure erectile dysfunction?

No.

Is tongkat ali safe?

Safety remains uncertain.

Is a commonly marketed daily dose proven safe?

No universal dose has been established as safe and effective.