Selective androgen receptor modulators have steroid effects but are believed to be safer, without many of the harmful side effects of steroids.
SARMs work similarly to testosterone but in a more targeted way. "They are effective by binding to the steroid receptor in only specific tissue, like muscle," says Evans, who is also a scientific advisor to GTx, a company developing the drugs. "They are not steroid drugs, but they produce the anabolic effect of the steroids." GTx, based in Memphis, TN, has shown in a clinical trial that one compound being developed for muscle wasting and bone loss can significantly boost lean muscle mass in older people.
Analysis of the solution revealed the presence of S-4 at approximately 150 mg/mL with equal amounts in each container, yielding a total of 4.5 g of the SARM
There are some posted logs and journals where people track the results of their SARM S4 usage.
There is a lot of fake SARMs being sold as well.