Tongkat Ali (Eurycoma longifolia), also known as Malaysian ginseng, is a Southeast Asian plant traditionally used to support male vitality. Today, it’s getting attention for its potential impact on testosterone, sexual function, and fertility. But what does the research actually show?
How It Works
Testosterone naturally declines with age — about 1–2% per year after age 30. By age 60, levels can be down to half of what they were in early adulthood. Stress, poor sleep, and inactivity only speed this up.
Unlike hormone therapy, Tongkat Ali doesn’t add testosterone from outside. Instead, it may help free up the testosterone already in the body by reducing the binding of testosterone to a protein called SHBG (sex hormone-binding globulin). Some studies also suggest it may slow down how quickly testosterone breaks down in the body, making more available for longer.
A study of men with low testosterone showed that taking 200 mg of Tongkat Ali daily for a month significantly increased testosterone levels and improved self-reported well-being
(Talbott et al., 2013).
In another study, men around age 51 saw improved hormone profiles after just four weeks of daily supplementation
(Leitão et al., 2021).
Sexual Function and ED
A double-blind, placebo-controlled study with 109 men tested a standardized water extract of Tongkat Ali over 12 weeks. Results showed improvements in libido, sexual satisfaction, and sperm motility
(Tambi et al., 2012).
In other trials, men with moderate to severe erectile dysfunction showed slight improvements after supplementing with Tongkat Ali. While the overall effects weren’t strong across all groups, there may be benefits for those with more serious symptoms.
Fertility
In one study, 75 men with poor semen quality took 200 mg of Tongkat Ali daily for up to 9 months. Results showed significant increases in sperm count, motility, and normal morphology
(Tambi et al., 2010). This is relevant for men dealing with subfertility, especially those avoiding testosterone replacement, which can reduce sperm production.
Muscle and Body Composition
Some small studies suggest Tongkat Ali might support muscle gain. In young men following a weight training program, those who took 100 mg daily saw greater increases in lean mass and arm circumference compared to the placebo group.
Side Effects and Risks
Reported side effects include insomnia, irritability, and restlessness — usually at higher doses (400–600 mg/day). Tongkat Ali may also lower blood sugar levels, so those on diabetes medication should use caution
(Chan et al., 2009).
It’s not recommended for people with hormone-sensitive cancers, serious heart or kidney conditions, or for pregnant or breastfeeding women. There’s not enough safety data for those groups.
Dosing and Quality
Most clinical studies used doses between 200–400 mg daily, often for 4 to 12 weeks. Some people follow an on/off cycle (e.g. one week on, one week off), but consistent daily use tends to show better results.
Look for standardized water-based root extracts — the type used in clinical studies. Avoid products with vague labeling or aggressive health claims. Reputable brands often verify their formulas with third-party testing (e.g., USP, NSF, ConsumerLab).
Bottom Line
Tongkat Ali isn’t a miracle cure, but the science suggests it can help normalize testosterone, improve sperm parameters, and support energy and libido — especially in men with low levels to begin with. It may be useful as part of a broader approach to men’s health, provided it’s used responsibly and with medical guidance.