Among herbs sold for testosterone, tongkat ali has some of the better human data. Still, the trials are small, most test a single branded extract, and many have industry ties. Here's what they found.
The evidence that tongkat ali (Eurycoma longifolia) raises testosterone is modest, and it applies mainly to men who start with low levels. A 2022 meta-analysis pooled five small trials (232 men) and found a significant overall rise. In men with normal levels, though, the increase wasn't statistically significant. Most studies gave 100 to 600 mg a day of a standardized water extract. The evidence remains limited.
The root of a Southeast Asian shrub, Eurycoma longifolia, is what we call tongkat ali. You may also see it sold as longjack or Malaysian ginseng. Traditionally people used it for low energy and libido. Today it turns up in many testosterone booster formulas.
Researchers mostly test a standardized hot-water root extract, not plain root powder. A branded extract called Physta shows up in most of the trials. It's standardized to a range of eurycomanone, one of the plant's marker compounds. This matters because findings on a tested extract can't be assumed to carry over to a cheap capsule of ground root.
Our best overview is a 2022 systematic review and meta-analysis in Medicina. Its authors located nine relevant human studies and pooled five randomized controlled trials with 232 men. Doses ran from 100 to 600 mg a day, and the trials lasted anywhere from 3 days to 6 months.
Across the pooled trials, total testosterone rose significantly more with tongkat ali than in control groups. The detail beneath that headline is what's worth knowing:
The authors called the herb promising, especially for men with low levels. They added that more research is needed before anyone could recommend it clinically.
Among the larger single trials is a 2021 study in Food & Nutrition Research. It enrolled 105 men aged 50 to 70 whose testosterone was below 300 ng/dL. For 12 weeks they took Physta at 100 mg or 200 mg a day, or a placebo.
Two authors were employed by Biotropics Malaysia, which makes Physta. That doesn't make the findings wrong, but it's a good reason to want independent replication.
In 2013, the Journal of the International Society of Sports Nutrition published a four-week trial of the same extract. It gave 200 mg a day or a placebo to 63 moderately stressed adults (32 men, 31 women). The tongkat ali group had 16% lower cortisol and 37% higher testosterone than placebo, along with small gains in tension, anger and confusion scores. Scores for depression, vigor and fatigue were no different between groups.
Biotropics Malaysia funded this trial, and several authors had commercial ties to the extract. It was also small and short.
It's stronger than for most herbal testosterone ingredients, yet still limited. The meta-analysis authors pointed out several weaknesses themselves:
So here is a fair reading: tongkat ali probably gives a modest testosterone rise in men who start low, and its effect in men with normal levels is uncertain. Fenugreek and testosterone sits in a similar spot, with real signals from small studies.
Across the human studies, doses of a standardized water extract ran from 100 to 600 mg a day, and 200 to 400 mg was a common range. No official recommended dose exists, and taking more hasn't been shown to work better.
Quality is a real concern. The meta-analysis cites testing of 24 Malaysian products containing eurycomanone, where only 11 met the recommended level. Another study found mercury contamination in some tongkat ali preparations. If you decide to buy it, look for these things:
For help checking labels and doses against the research, see our guide on how to choose a testosterone supplement.
Over periods of up to a few months, trial participants generally tolerated tongkat ali well. The meta-analysis notes that one study reported stomach upset and itching, and another recorded adverse events in both the treatment and placebo groups. Nobody has studied its long-term safety.
Speak with your doctor first, and skip it unless they agree, if you:
Keep in mind too that the FDA doesn't approve supplements before they're sold, and some sexual-performance and "testosterone" products have turned out to contain undeclared prescription drugs. A reputable, tested brand lowers that risk.
It makes the most sense for a man with borderline-low testosterone or stress-related fatigue who wants a supplement with some human data behind it, once bigger causes have been ruled out. Haven't been tested? Begin there. Our piece on low testosterone symptoms in men explains what testing involves and covers common, fixable causes such as weight, sleep apnea and medications.
Tongkat ali doesn't replace treatment if you have clinical hypogonadism. It also isn't likely to do much for a young man whose testosterone is already normal.
Tongkat ali ranks among the better-studied herbal testosterone ingredients, and the trials suggest a modest increase, mostly in men who start low. But the data come from a few small studies of one extract, many linked to the company, with signs of publication bias. If you try it, pick a standardized extract at 200 to 400 mg a day and buy a third-party tested product. Check with your doctor first if you have a prostate condition or take hormone-related drugs. Then judge it by a follow-up blood test, not by how you feel in week one.