Tongkat ali inhibits aromatase and phosphodiesterase
Recent research has helped explain how Tongkat Ali (scientific name: Eurycoma longifolia) may offer the dual benefits of improving sexual function and supporting muscle mass. The mechanism is believed to involve the inhibition of two specific enzymes: aromatase and phosphodiesterase.
A relevant scientific study can be found here:
Steroidogenesis is the biological process of producing steroid hormones, including testosterone.
Scientific studies are often difficult to read for those not specifically educated in the field of the research. However, there is no substitute for peer-reviewed literature. Any claims regarding pharmaceutical actions that are not supported by scientific studies are likely baseless.
I view it as one of my tasks to refer to scientific research and elaborate on its practical impacts.
Scientifically minded bodybuilders know that aromatase is an enzyme that converts testosterone into estrogen. While testosterone is highly anabolic and builds muscle, it is a misconception that estrogen merely "builds breasts and inhibits muscle growth." In reality, physiological levels of estrogen are crucial for male joint health, bone density, and even muscle recovery. However, excess estrogen, often caused by supraphysiological testosterone levels, can lead to water retention and gynecomastia.
Gynecomastia is the development of female breast tissue in men. Among bodybuilders, this is commonly referred to as "gyno."
While anabolic steroids have a dramatic effect on muscle mass, they also carry side effects, which is why they are strictly controlled prescription drugs. Gyno is one of these potential side effects when testosterone converts excessively to estradiol.
To combat the estrogenic side effects of anabolic steroids, bodybuilders typically use pharmaceutical aromatase inhibitors (AIs) or selective estrogen receptor modulators (SERMs). While some may experiment with Tongkat Ali extract due to its mild in vitro aromatase-inhibiting properties, it is not a replacement for clinical anti-estrogens in the context of heavy steroid use. The scientific study referred to above, however, highlights the natural mechanisms of the plant's active compounds.
Beyond aromatase, Tongkat Ali is also thought to inhibit another enzyme: phosphodiesterase (specifically PDE5).
Phosphodiesterase type 5 (PDE5) breaks down cGMP, a molecule necessary for smooth muscle relaxation and blood flow in the corpus cavernosum. When PDE5 is overactive or as men age, erectile function can decline. Pharmaceutical PDE5 inhibitors, such as sildenafil (Viagra) and tadalafil (Cialis), block this enzyme, allowing men to achieve and maintain erections. It is important to correct a common misconception: PDE5 itself does not shut down sperm production or shrink testicles. Testicular atrophy and suppressed spermatogenesis are caused by the use of exogenous anabolic steroids, which shut down the body's natural hormonal axis. PDE5 inhibitors do not cause testicular shrinkage.
Tongkat ali, by potentially inhibiting both phosphodiesterase and aromatase, aims to support natural testosterone production, improve erectile function, and enhance libido, largely without the side effects associated with synthetic drugs—provided the Tongkat Ali extract is genuine and properly standardized.
Unfortunately, a significant portion of what is sold online as Tongkat Ali is actually Tribulus terrestris, or undisclosed synthetic powders blended with other herbs, often originating from unregulated markets.
It is amazing how willing people are to send money to random online marketplace sellers who offer counterfeit products and claim they are pure Tongkat Ali, without providing any verifiable reference to the source of their product or a single authentic photo of their facilities.
My advice is: buy a genuine, third-party tested Tongkat Ali extract, or simply go without it.
Genuine Tongkat Ali extract is certainly not cheap, but it is worth the investment for those who prioritize quality and safety.