Taking tongkat ali supplement, or Eurycoma longifolia, may help with mood and hormone regulation, but research is still new. Side effects can also occur, so it’s best to contact a doctor before taking tongkat ali supplements.

Tongkat ali is an herbal remedy that has been a part of traditional Southeast Asian medicine for centuries.

People sometimes use it to treat a variety of ailments, including fevers, erectile dysfunction, and bacterial infections.

Studies suggest that tongkat ali may boost male fertility, relieve stress, and improve body composition, though research in these areas is limited.

The European Food Safety Authority issued a warning in 2021 that tongkat ali has the potential to induce DNA damage.

This article reviews tongkat ali, including its benefits, possible side effects, and dosage.

Tongkat ali, or longjack, is an herbal supplement that comes from the roots of the green shrub tree Eurycoma longifolia, which is native to Southeast Asia.

It’s used in traditional medicine in Malaysia, Indonesia, Vietnam, and other Asian countries, potentially offering the following properties:

  • antimalarial
  • antibacterial
  • antidiabetic
  • antipyretic

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.

However, it’s important to note that the European Food Safety Authority in 2021Trusted Source tongkat ali might cause DNA damage. Before taking tongkat ali, you should discuss the possible risks with your doctor.

Most of the alleged health benefits of tongkat ali are not well researched, but some studies suggest that it may help treat male infertility, improve mood, and increase muscle mass.

May increase testosterone levels and improve male fertility

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 studyTrusted Source 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 studyTrusted Source 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.

According to these studies, tongkat ali has the potential to treat low testosterone and infertility in some people, but more extensive research is necessary.

May relieve stress

Tongkat ali may lower stress hormones in your body, decrease anxiety, and improve mood.

A 1999 studyTrusted Source 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.

While these results are promising, more studies in humans are necessary. If you have concerns about stress, you can contact your doctor for advice on ways to manage it.

Learn more about ways to relieve stress.

May improve body composition

There are some claims that tongkat ali may boost athletic performance and increase muscle mass.

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 studyTrusted Source in 25 active older adults discovered that supplementing with 400 mg of tongkat ali extract daily significantly increased muscular strength, compared to a placebo.

However, a 2024 study that assessed the effects of taking 400 mg of tongkat ali daily did not improve body composition in exercise-trained males and females.

These conflicting results suggest that tongkat ali may exhibit some ergogenic effects, depending on the dose and length of treatment, but more research is necessary to better understand this.

According to a 2021 reportTrusted Source 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.

The same study found the lethal oral dose for mice was from 1,500 to 2,000 mg/kg for alcohol-based tongkat ali extract, and over 3,000 mg/kg for the water-based extract.

Some studiesTrusted Source suggest that taking up to 1.2 grams of tongkat ali extract per day is safe for adults, but this amount has not been used in research. Plus, no studies examine its long-term use, making it unclear whether the supplement is safe over longer periods.

A 2006 studyTrusted Source examining the mercury content of 100 tongkat ali supplements from Malaysia found that 26% had levels of mercury higher than the recommended limit.

Consuming too much mercury can result inTrusted Source mercury poisoning, which is characterized by mood changes, memory problems, and motor skill issues.

Furthermore, the effects of tongkat ali in children or pregnant and nursing people have not been researched. Therefore, it’s unknown whether the remedy is safe for these populations.

While tongkat ali does not appear to have adverse effects in doses up to 400 mg per day, research is limited, and available studies focus on short-term use.

It’s unclear whether taking the supplements over longer periods is beneficial and safe.

If you’re interested in taking tongkat ali, consult your healthcare provider to ensure proper safety.

Additionally, keep in mind that some supplements may be contaminated with mercury. Plus, they’re not well regulated and may contain more or less tongkat ali than listed on the label. Look for a reputable brand that has been tested by a third party.

Lastly, pregnant and nursing people should not take tongkat ali, due to the lack of research in this area. Additionally, those with medical conditions or taking medications should speak to their healthcare provider before taking tongkat ali.

Tongkat ali, or Eurycoma longifolia, is an herbal supplement that has the potential to improve low testosterone, reduce stress, and enhance athletic performance.

However, current research is limited. Tongkat ali may also cause DNA damage and other potentially serious side effects.

If you’re interested in trying tongkat ali, talk with a medical professional beforehand. They can advise on whether the supplement is safe for you to take.