S23 is an orally active nonsteroidal 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.
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.
Alternative Uses: A 2009 study performed on rats showed potential for S-23 to be used as a male contraceptive. In this study, six rats were given a dose of 0.1 mg per day for 10 weeks. As a result, both LH (Luteinizing Hormone) and FSH (Follicle-Stimulating Hormone) levels decreased. These effects were statistically significant, since four of the six rats had no sperm in the testis. What's more, none of the rats was able to impregnate a female rat during mating trials. However, this contraceptive effect was temporary - after just 100 days from last dose the infertility was reversed, and there was a 100% pregnancy rate.
Dosages and Cycles: 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. Nonetheless, this is not recommended because there have not been studies done on humans to replicate the contraceptive effect shown in rats.
In spite of the fact that after 100 days the rats did recover natural testosterone levels, humans would need to run a full PCT (Post Cycle Therapy). Since S-23 causes severe suppression, I would always recommend the Perfect PCT.
Conclusion: 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.