S-23 is a selective androgen receptor modulator (SARM) that has been studied primarily in laboratory and preclinical research settings. SARMs are a class of compounds designed to interact with androgen receptors in a more targeted way than traditional anabolic steroids, with the goal of producing tissue-specific effects while reducing systemic side effects. S-23 has attracted scientific interest due to its strong binding affinity to androgen receptors and its potential role in hormonal and metabolic research. From a mechanistic perspective, S-23 works by selectively activating androgen receptors in certain tissues such as muscle and bone. This selective interaction has made it useful for studying muscle physiology, endocrine signaling, and the regulation of reproductive hormones in controlled experimental environments.