What is tongkat ali?

Tongkat ali (Eurycoma longifolia), also known as long jack, is an herbal plant that grows in Malaysia and other parts of Southeast Asia. It has been used traditionally for centuries as an energy enhancer and aphrodisiac, and to reduce fevers, blood pressure, and fatigue. Tongkat ali as an ingredient in dietary supplements is often marketed to boost testosterone levels, reduce stress, improve mood, and enhance athletic and sexual performance.

More evidence is needed to confirm any marketed benefits of tongkat ali. The safety of tongkat ali in humans hasn’t been fully established.

Tongkat ali is commonly sold in the form of a powder, extract, drink, or capsule. The root (or the root extract) contains various chemical compounds, which are thought to be responsible for its many claimed health benefits. Products list this ingredient either alone or in combination with other ingredients such as Tribulus terrestris, Fadogia agrestis, horny goat weed, ginseng, and L-arginine.

What are the possible side effects of tongkat ali?

  • In 2021, the European Food Safety Authority issued a warning that tongkat ali root extract has the potential to cause DNA damage in animals and stated its overall safety has not been established.
  • Studies involving humans to date suggest tongkat ali in small doses (short term) is generally safe when used orally. Reported side effects include gastrointestinal issues and itching. 
  • Products containing tongkat ali have been reported to be contaminated with heavy metals (such as lead and mercury) or adultered with sildenafil (a prescription drug used to treat erectile dysfunction).

Are there any benefits of tongkat ali?

  • Some studies in animals and humans suggest that tongkat ali might increase testosterone levels and improve aspects of sexual health such as male fertility, erectile dysfunction, and libido.
  • A few studies suggest that tongkat ali might increase muscle strength in men.
  • Studies to date have reported no beneficial effects of tongkat ali on endurance performance.
  • Overall, studies have been small and short-term in length. More high-quality research is needed to confirm any beneficial effects.

Will tongkat ali cause a positive drug test? Is it prohibited for Service Members?

Tongkat ali isn’t on the DoD Prohibited Dietary Supplement Ingredients List, and it shouldn’t cause a positive result on a routine military drug test. However, as mentioned above, products containing tongkat ali could be contaminated with drugs (prescription or unapproved) or heavy metals. Without laboratory testing there is no way to know the actual ingredients (or their amounts) in a product, so check the label to see if it has been evaluated by an independent, third-party organization.


Posted 21 April 2023


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