Testolone, also known as RAD-140, is a selective androgen receptor modulator (SARM) that has been investigated for its potential to support the testosterone body system, particularly with regard to muscle growth, strength, and prevention of muscle wasting. Unlike anabolic steroids, SARMs like Testolone are designed to selectively target androgen receptors in muscle and bone tissues, theoretically offering anabolic benefits without the severe side effects associated with traditional steroid use.

Preclinical studies and limited human trials have shown that RAD-140 can increase lean muscle mass and improve strength in healthy volunteers as well as in populations at risk of muscle wasting, such as those with age-related sarcopenia or certain types of cancer. For example, a phase I clinical trial (2017) indicated that RAD-140 was generally well tolerated and demonstrated dose-dependent increases in lean body mass in healthy volunteers.

However, while the mechanism of action is well understood and preclinical results are promising, large-scale, long-term clinical trials are lacking. The FDA has not approved RAD-140 for medical use, and its safety profile, especially over long periods, remains to be fully established. Nonetheless, the available scientific evidence supports its role in modulating the androgen (testosterone) system, making its use scientifically grounded rather than purely traditional or anecdotal.