Tongkat Ali (Eurycoma longifolia) is a popular herbal supplement marketed for its ability to support testosterone levels in men. This root extract is often used to improve physical performance, mood, and sexual health. Concerns have arisen regarding the possibility of developing gynecomastia, which is the development of male breast tissue often linked to an imbalance between sex hormones. Understanding how this supplement interacts with the body’s hormonal system is necessary to assess the actual risk of this side effect.
Understanding Tongkat Ali’s Hormonal Impact
Tongkat Ali does not introduce testosterone directly but works through indirect mechanisms that influence the body’s existing hormone production. One of its primary actions involves reducing Sex Hormone Binding Globulin (SHBG), a protein that circulates in the bloodstream. SHBG binds to testosterone, making it inactive or “bound.” By decreasing SHBG, Tongkat Ali increases the amount of “free” testosterone available for the body’s tissues to use, which is the bioactive form of the hormone.
The herb may also influence the aromatase enzyme, which converts testosterone into estradiol, a form of estrogen. Compounds in Tongkat Ali, such as eurycomanone, have been suggested to inhibit this conversion process. This dual action—increasing free testosterone while potentially reducing its conversion to estrogen—is thought to improve the overall testosterone-to-estrogen (T:E) ratio. This mechanism is important for understanding its safety profile, as high estrogen levels relative to testosterone are the main cause of gynecomastia.
The Scientific Consensus on Gynecomastia Risk
Gynecomastia occurs when estrogenic activity outweighs androgenic activity in male breast tissue. Since Tongkat Ali’s mechanism generally increases the T:E ratio, scientific evidence suggests that pure, standardized extracts do not increase the risk of developing gynecomastia. Clinical studies have generally not reported gynecomastia as a side effect, and there is no established confirmation that the herb directly causes the condition.
The most common cause of gynecomastia related to hormone manipulation is a significant increase in total testosterone, which then leads to a corresponding spike in estrogen through the aromatase process. Tongkat Ali typically does not elevate total testosterone levels to the supra-physiological levels seen with synthetic anabolic steroids. Increases observed in studies are generally modest, particularly in men with already low testosterone levels.
One study noted an increase in estradiol alongside total and free testosterone in young, healthy males taking a high dose (600 mg/day) for two weeks. This suggests that an estrogen increase can still occur, even if the T:E ratio improves. However, the overall hormonal balance achieved by Tongkat Ali typically favors the androgenic side. This keeps the risk of estrogen-related side effects low compared to compounds that solely spike testosterone without anti-estrogenic properties.
Dosage, Supplement Quality, and Individual Risk Factors
The risk profile of Tongkat Ali is highly dependent on the quality and dosage of the supplement consumed. Clinical studies often use standardized, water-soluble extracts, with typical dosages ranging from 200 to 400 milligrams daily. Non-standardized products, or those using high-ratio extracts like 200:1 without specifying active compounds, can have inconsistent potency. This inconsistency makes predicting their hormonal effects difficult.
A major concern in the supplement market is the presence of poor quality or adulterated products. Some supplements marketed as Tongkat Ali have been found to be illegally spiked with synthetic steroids, prohormones, or other unlisted compounds known to cause gynecomastia. When users experience gynecomastia after taking a Tongkat Ali product, the cause is often this contamination, not the pure herb itself.
Individual sensitivity and pre-existing hormonal conditions also play a role in risk. Men who already have a tendency toward higher estrogen levels or have underlying hormonal imbalances should exercise caution and consult a healthcare professional before use. Even with a pure product, a small portion of the population may respond differently to the hormonal shifts. Adhering to the recommended dosage of a third-party tested, standardized extract minimizes the already low risk of adverse hormonal effects.