Testolone (RAD-140)

Testolone (RAD-140) is a selective androgen receptor modulator (SARM) associated with muscle growth, strength development and lean muscle mass. In bodybuilding, Testolone is primarily discussed in connection with bulking phases, muscle hypertrophy and maintaining muscle mass during calorie-restricted periods.

Testolone binds to androgen receptors in muscle and bone tissue, activating anabolic signalling involved in muscle protein synthesis and tissue development. Its intended effects include increased lean muscle mass, improved strength and support for muscle preservation. RAD-140 was developed to provide more selective androgen receptor activity than traditional anabolic steroids, with a focus on anabolic effects in muscle and bone. Testolone and RAD-140 are two names for the same active compound, not different formulations or esters.