Developed by GTx, S-23 is an orally active nonsteroidal SARM with a very high binding affinity to androgen receptors. This makes it stronger than other popular SARMs like Ostarine (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.
Additionally, in a study done on rats a dose equivalent to 15 milligrams (mg) for a 180lb male was shown to also increase bone mineral density, as well as promote muscle mass growth and fat loss. Hence, S-23 is versatile in that it can be used for bulking and for cutting.
Note; dosage information is only for scientific reference purposes. SARMs Central, does not condone the human consumption or use of this substance outside of a controlled scientific environment (i.e. a lab).
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 mgs per day would be appropriate. On the other hand, if someone was looking to use it for the contraceptive effects, a higher dose of around 50 mgs per day would be more effective
Potential 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. Unfortunately, there have not been any human studies, so not much is known on other potential side effects.
S-23 has many potential benefits that range from muscle building and fat loss, to being a possible male contraceptive. Even though this SARM may seem very intriguing, it is still in a very early stage of development and study.
Thus, I would proceed with caution when considering this compound. Keep in mind that there are other SARMs on the market today, such as ostabolic and testolone, which give similar muscle building and fat loss effects and are much more studied. Besides, other SARMs will also cause much less suppression of natural testosterone production, allowing the user to run a considerably milder and shorter PCT.
All in all, I would recommend sticking to the tried and true until more research is done on S-23. In simple terms, stay away from this SARM until we know more.