s-23 (drug) s-23 (drug) s-23 is an investigational selective androgen receptor modulator (sarm) developed by gtx, inc as a potential male hormonal contraceptive. it binds to the androgen receptor more strongly than older drugs such as andarine with a ki of 1.7 nm, and in animal studies it showed both a good ratio of anabolic to androgenic effects, and dose-dependent suppression of spermatogenesis with spontaneous recovery after cessation of treatment. s-23legal statuslegal status us: investigational new drug identifiers iupac name (2s)-n-(4-cyano-3-trifluoromethylphenyl)-3-(3-fluoro-4-chlorophenoxy)-2-hydroxy-2-methyl-propanamide cas number1010396-29-8 npubchem cid24892822drugbankdb07419 nchemspider24715019 nuniixdk89456wmchemical and physical dataformulac18h13clf4n2o3molar mass416.76 g·mol−13d model (jsmol)interactive image smiles c(coc1=cc(=c(c=c1)cl)f)(c(=o)nc2=cc(=c(c=c2)c#n)c(f)(f)f)o inchi inchi=1s/c18h13clf4n2o3/c1-17(27,9-28-12-4-5-14(19)15(20)7-12)16(26)25-11-3-2-10(8-24)13(6-11)18(21,22)23/h2-7,27h,9h2,1h3,(h,25,26)/t17-/m0/s1 nkey:ssfvoeaxhzgtrj-krwdzbqosa-n n ny (what is this?) (verify)