Tongkat Ali for testosterone and libido: what studies show (table)

Tongkat ali, or the root Eurycoma longifolia, has made its way into supplements with the promise of influencing testosterone, libido, and stress resistance. Behind this promise are a few small studies on humans. In a randomized placebo trial involving 63 individuals with moderate stress, four weeks of supplementation with a standardized aqueous extract reduced cortisol in saliva by 16% and increased testosterone by 37% (Talbott i in., Journal of the International Society of Sports Nutrition 2013). This article gathers what was actually measured: who studied it, how many participants there were, how long the supplementation lasted, and what the results were. We do not present the numbers from the studies as recommendations.

KEY INFORMATION
• Salivary cortisol decreased by 16%, testosterone increased by 37% after four weeks in 63 individuals with stress (Talbott i in., 2013).
• The strongest data comes from men with low testosterone, not from young and healthy individuals.
• Both randomized trials were funded by the manufacturer of the studied extract.
• Three out of five studies did not have a control group.
• The use in case of illness and medications is determined by a doctor, not the label.

What is tongkat ali and how does it work?

Tongkat ali is the root of a tree Eurycoma longifolia, growing in Southeast Asia. In supplements, it most often appears as an aqueous extract. The root does not contain hormones or their precursors, so the changes in testosterone levels observed in studies do not result from external hormone supply, but from some shift in internal regulation.

How exactly this mechanism works in humans has not been determined. The clinical publications described below measured the outcome, not the pathway the body took to reach it. There is an elaborate description circulating online regarding the inhibition of aromatase and stimulation of Leydig cells via the cyclic AMP pathway. We did not find it in any of the clinical studies cited in this text, so we do not repeat it.

One mechanistic clue comes from a pilot study involving older individuals. The increase in free testosterone among participants is linked by the authors to a decrease in sex hormone-binding globulin levels, which is a transport protein determining what portion of the hormone remains biologically active (Henkel i in., Phytotherapy Research 2014). This is one small trial, so it is a clue, not a conclusion.

A separate issue concerns who the effect was measured in. Participants were men diagnosed with late-onset hypogonadism, men aged 30-55, individuals with elevated stress, and physically active seniors. There are no trials involving young adults with normal hormone levels in this set, so extrapolating these numbers to them is an overinterpretation.

Jakie badania nad tongkat ali przeprowadzono na ludziach?

There are several trials, and all are small. The largest involved 350 patients, and the smallest 25 individuals. Supplementation lasted from one month to twelve weeks, and the preparations varied enough that the results cannot be combined into a single number.

Two things need to be read together with the results. First, three out of five studies had no control group or blinding, and one is explicitly called a pilot study by the authors. Second, both randomized trials were funded by the same Malaysian company producing the studied extract, and an employee of this company is listed as an author in both; they state this openly. This does not invalidate the measurements, but the reader has the right to know that the strongest numbers on this topic come from studies funded by the manufacturer.

After what time did changes appear in the studies?

The shortest trial lasted four weeks, and that was enough to see a difference compared to placebo in the hormone profile in saliva and in mood scales (Talbott i in., 2013). A month of observation of patients with late hypogonadism was sufficient for the percentage of individuals with normal serum testosterone to increase from 35.5% to 90.8% (Tambi i in., Andrologia 2012).

Longer endpoints yield different results. In Ismail's study, the difference in libido increased gradually and was only reported for the twelfth week, while the improvement in semen parameters in Tambi's 2010 study required a full three-month cycle, which the authors accepted as the unit of observation. Shorter observation would have nothing to measure.

If you are looking for a verifiable reference point, the most reliable reference is a laboratory test conducted before the start and after the end of the observation: total testosterone, free testosterone, and sex hormone-binding globulin. These same parameters were used in the described studies. Without them, you are only assessing well-being, which also changes in groups receiving placebo.

How to recognize a well-described extract?

The extraction ratio stated on the packaging as 100:1 or 200:1 only indicates how much raw material was used per unit of extract. It says nothing about the content of the substances in question. A product with a lower ratio may be better described than one with a higher ratio, as these are two different pieces of information.

In clinical publications, products were described differently. Ismail and his team provide a lyophilized water extract called Physta, Talbott a standardized water extract from the root, Tambi a standardized water-soluble extract. The common denominator of all trials is water extraction and declared standardization, not the extraction ratio. A label that only states 200:1 has not yet provided any information about the composition.

There are two practical conclusions. Look for information about the type of extract and what component it is standardized for. Treat the absence of this information as a lack of information, not as a trivial detail. Athletes subject to anti-doping control have an additional reason to be cautious: plant supplements can be contaminated with substances from the banned list, and independent batch testing programs, such as NSF Certified for Sport or Informed Sport, reduce this risk.

What do studies say about semen and fertility?

The most frequently cited number in this context is often reported incorrectly, so it is worth setting it straight. In a study published in the Asian Journal of Andrology in 2010, 350 patients with idiopathic infertility received 200 mg of extract daily, and semen analyses were repeated every three months for nine months. A full three-month cycle was completed by 75 patients, and significant improvements in all semen parameters were recorded, along with 11 spontaneous pregnancies, which is 14.7% of this group (Tambi i Imran, 2010).

In this study, there was no control group. Therefore, the percentage of 14.7% has nothing to compare to. It is sometimes compared to an alleged control group and a result of 2.6%, but in the original, there is neither such a group nor such a number. Without control, it is impossible to separate the effect of the preparation from the natural course and the passage of time, and idiopathic infertility, by definition, has no established cause.

The second source of data on semen is methodologically stronger. A randomized placebo trial involving 109 men describes sperm motility of 44.4% and semen volume of 18.2% after twelve weeks (Ismail i in., 2012). However, these were men aged 30-55 recruited for a study on libido and quality of life, not patients treated for infertility. A similar pattern of evidence was described for another plant in the text about ashwagandzie i parametrach nasienia. In the case of confirmed fertility issues, an andrologist leads the treatment, and supplements do not replace diagnostics.

Does tongkat ali lower cortisol?

In one randomized trial, yes. Talbott and his team provided a standardized water extract to 63 individuals classified as moderately stressed and measured cortisol in saliva, which was lower by 16%, and testosterone in saliva, which was higher by 37% compared to placebo after four weeks. Three mood scales also improved: tension by 11%, anger by 12%, and confusion by 15%.

Two clarifications change the weight of this result. Hormones were measured in saliva, not in serum, so this is not the same endpoint as in studies on hypogonadism. The group was mixed-gender, consisting of 32 men and 31 women, and the results were not broken down by gender in the summary. The aforementioned funding by the manufacturer pertains specifically to this work.

The comparison of tongkat ali with other plants described as adaptogens should be approached cautiously: one trial involving 63 people is too small to establish its hierarchy. We discuss more about which plants have stronger backing in this area in the review. supplements for stress and cortisol, a osobno omawiamy tulsi, or holy basil.

Has tongkat ali been studied in women?

Women participated in two out of the five described studies, but in none were they analyzed as a separate group. In Talbott's study, there were 31 women among 63 participants, and in Henkl's study, 12 out of 25. This is all we have, and it is significantly less than the data available for men.

The only observation explicitly described as concerning women comes from a pilot study on seniors: the increase in free testosterone was attributed by the authors to a decrease in the concentration of sex hormone-binding globulin. In the same study, testosterone levels and grip strength remained significantly lower in female participants than in male participants, which is an expected physiological difference, not an effect of the supplement.

The conclusion is cautious. There is no basis to claim that tongkat ali does not work in women, nor to assert that it works the same way as in men. This has not been studied. There is no safety data during pregnancy and breastfeeding, so use is not recommended. In the case of hormonal contraception and hormone therapy, the decision is made by the attending physician, as the supplement affects the same axis.

Who is tongkat ali recommended for?

The longest randomized safety observation lasted three months. The authors found that all analyzed safety parameters and adverse events were comparable to placebo, and in their conclusions, they noted that such supplementation is well tolerated (Ismail i in., 2012). There are no longer observations in this set, so nothing is known about the safety of year-long use.

The groups for which use is not recommended or requires a doctor's decision arise directly from what has not been studied. Pregnancy and breastfeeding lack any data. Hormone-dependent cancers, testosterone therapy, and hormone treatment are situations where a supplement affecting the hormonal axis should not be added without the knowledge of the attending physician. Individuals taking medications regularly have the same reason to consult their doctor.

Descriptions circulating online of tongkat ali as an immune booster or harmful to the liver have no support in the studies described above, and therefore we do not repeat them here. This does not mean they are false. It means we have not found a source we could rely on. We have gathered more information about what has been studied in this age group and what has not in the text about supplements for men over 40..

Frequently Asked Questions

What were the doses used in studies on tongkat ali?

In the described studies, it ranged from 200 mg to 400 mg of extract per day, over a period of one month to twelve weeks. Tambi's team used 200 mg, Ismail used 300 mg of Physta extract, and Henkel used 400 mg. This is a description of research protocols, not a recommendation for the reader. The decision to use the supplement is made by a doctor.

How quickly does tongkat ali raise testosterone?

The shortest randomized trial showed a difference compared to placebo after four weeks, but it measured testosterone in saliva. A month was also sufficient for patients with late-onset hypogonadism, where the percentage of individuals with normal serum levels increased from 35.5% to 90.8%. Endpoints related to semen required a full three months.

Is tongkat ali proven to be safe?

In a three-month placebo trial involving 109 men, safety parameters did not differ from the control group. This is the longest observation we found. Longer use has not been studied, and there is no data at all for pregnancy, breastfeeding, and hormone-dependent cancers.

Did 76% of participants achieve normal testosterone levels?

No, and this is a common misreading. The number 76 in this study refers to the number of patients, not a percentage: 76 out of 320 patients with late-onset hypogonadism received the extract. The percentage of individuals with normal testosterone levels increased from 35.5% before treatment to 90.8% after one month.

Can tongkat ali be combined with ashwagandha?

We did not find a study that evaluated such a combination in humans. Both plants have their own separate clinical trials, but no one has checked a common protocol. Opinions about complementary mechanisms are reasoning, not measurement results. When taking medications, discuss any combination of preparations with your doctor.

Which extract is better, 100:1 or 200:1?

The extraction ratio alone does not determine this, as it refers to the amount of raw material, not the content of active ingredients. In clinical studies, preparations were described by the type of extract and standardization, most often as standardized aqueous extracts. A label providing only the extraction ratio leaves the question of composition unanswered.

Does tongkat ali work in women?

This has not been studied separately. Women participated in two studies, totaling 43 individuals, but the results were not analyzed by gender. The only observation explicitly described for women concerns a decrease in sex hormone-binding globulin levels in a pilot study involving older women. Use during pregnancy and breastfeeding is not recommended.

Plant supplements described as adaptogens have been collected in the category adaptogens; tongkat ali is not currently included in it.

This article is for informational and educational purposes and does not constitute medical advice. Before starting supplementation, consult your doctor, especially if you are taking medications regularly, are pregnant or breastfeeding, or have a chronic illness.

Author: Michał Waluk · Opublikowano: 2026-07-08 · Aktualizacja: 2026-08-16