What is Tongkat Ali?
Tongkat ali (Eurycoma longifolia Jack), also known as “Long Jack”, is a flowering, shrubby, slow growing tree native to Southeast Asia, the leaves, roots, and bark of which have been used extensively in traditional medicine for many conditions including diabetes, arthritis, liver diseases, malaria, dysentery, and erectile dysfunction. It has recently become a popular herbal supplement in the United States, as extracts of tongkat ali roots have been promoted as increasing testosterone levels and improving athletic performance.
Traditional Uses
Tongkat Ali extract powder is a potent aphrodisiac and remedies fever. In traditional medicine, people used the roots, bark, and fruits of this flowering plant as natural remedies to cure a host of health conditions, including:
The health benefits of tongkat ali likely stem from various compounds found in the plant. Specifically, tongkat ali contains flavonoids, alkaloids, and other compounds that act as antioxidants. Antioxidants are compounds that fight cellular damage caused by molecules called free radicals. They may benefit your body in other ways as well.
Health Benefits
Male Infertility and Testosterone
Tongkat ali has the potential to increase testosterone. Effects of inadequate testosterone levels include low libido, erectile dysfunction, and in some cases, infertility. Since compounds in tongkat ali may boost low testosterone, it could treat these issues.
A 6-month 2021 study in 45 men with androgen deficiency of aging males showed some promising results. It found that taking 200 milligrams (mg) of Eurycoma longifolia daily alongside training increased overall levels of testosterone.
A 1-month 2012 study in 76 older men with low testosterone showed some promising results. It found that taking 200 mg of tongkat ali extract per day significantly increased levels of this hormone to normal values in over 90% of participants.
A 2010 study in 75 male partners of couples with infertility found that taking 200 mg of tongkat ali extract per day significantly improved sperm concentration and motility after 3 months. The treatment potentially helped over 14% of couples become pregnant.
May Relieve Stress
Tongkat ali may lower stress hormones in your body, decrease anxiety, and improve mood.
A 1999 study first identified the possible role of this remedy in treating mood issues and found that tongkat ali extract was comparable to a common anti-anxiety medication in reducing symptoms of anxiety in mice.
Similar effects have been seen in humans, but research is limited.
A 1-month 2013 study in 63 adults with moderate stress found that supplementing with 200 mg of tongkat ali extract per day reduced levels of the stress hormone cortisol in saliva by 16%, compared with those who received a placebo.
Participants also reported significantly less stress, anger, and tension after taking tongkat ali.
May Increase Energy and Endurance
This is because it contains compounds called quassinoids, including eurycomaoside, eurycolactone, and eurycomanone, which may help your body use energy more efficiently, reduce fatigue, and improve endurance.
A 5-week 2014 study in 25 active older adults discovered that supplementing with 400 mg of tongkat ali extract daily significantly increased muscular strength, compared to a placebo.
Possible Side Effects
According to a 2021 report by the European Food Safety Authority (EFSA) Panel on Nutrition, Novel Foods and Food Allergens, a high dose (2,000 mg/kilogram body weight) of the water-based extract from dried ground tongkat ali may lead to DNA damage of stomach and duodenum tissues.
Because tongkat ali has the potential to cause DNA damage, the panel concluded that the safety of any condition of its use has not been established.
However, there is limited information from human and adult studies about possible side effects. A 2016 review that included toxicology studies found that mice did not experience changes in their liver or kidney function when they were orally given 200 mg/kg body weight of tongkat ali in an alcohol-based extract or 300 mg/kg in a water-based extract.