S-23 is a selective androgen receptor modulator (SARM) and has been studied and proven to increase muscle mass, reduce fat mass, and has a very high binding affinity to the androgen receptors. S-23 is non-steroidal and has tissue-selective anabolic effects in muscle and bone, while sparing other androgenic effects that come from anabolic androgenic steroids. It also has been shown to decrease prostate size in studies, which is the opposite of a very common negative side effect of anabolic steroids (enlargement of the prostate).
90 x 10mg capsules
Developed by GTx, S-23 is an orally active non-steroidal SARM with a very high binding affinity to androgen receptors. This makes it stronger than other popular SARMS like Ostabolic (mk-2866) or Andarine (S-4). Therefore, the main effects of S-23 are increased muscle mass, decreased fat mass, and a decrease in the size of the prostate.
S-23 side effects
The main side effect of S-23 use is the suppression of natural testosterone production. This is what gives it potential as a male contraceptive, and also makes it very different from other SARMS. While Ostarine (ostabolic), Andarine (s4), and Anabolicum (LGD) may cause a mild shut down, S-23 is extremely suppressive. Consequently, this will be a major factor in deciding whether to use this SARM or opt for the more widespread choices.
Dosages of S-23 can vary, and they will be very dependent on what the goal is. For instance, if a user were looking for muscle building and fat loss, a dose of 15-25 mg per day would be appropriate. On the other hand, if someone is looking to use it for the contraceptive effects, a higher dose of around 50 mg per day would be more effective. Nonetheless, this is not recommended because there have not been studies done on humans to replicate the contraceptive effect shown in rats.