drostanolone drostanolone drostanolone, or dromostanolone, is an anabolic–androgenic steroid (aas) of the dihydrotestosterone (dht) group which was never marketed. an androgen ester prodrug of drostanolone, drostanolone propionate, was formerly used in the treatment of breast cancer in women under brand names such as drolban, masteril, and masteron. this has also been used non-medically for physique- or performance-enhancing purposes. drostanoloneclinical datatrade namesdrolban, masteril, masteron, others (all as drostanolone propionate)other namesdromostanolone; 2α-methyl-4,5α-dihydrotestosterone; 2α-methyl-dht; 2α-methyl-5α-androstan-17β-ol-3-oneroutes ofadministrationintramuscular injection (as drostanolone propionate)drug classandrogen; anabolic steroidlegal statuslegal status ca: schedule iv us: schedule iii identifiers iupac name (2r,5s,8r,9s,10s,13s,14s,17s)-17-hydroxy- 2,10,13-trimethyl-1,2,4,5,6,7,8,9,11,12,14,15,16,17- tetradecahydrocyclopentaphenanthren-3-one cas number58-19-5 ypubchem cid6011chemspider5789 nunii7dr7h00hdtchemblchembl1582 ncomptox dashboard (epa)dtxsid6022971 echa infocard100.000.334 chemical and physical dataformulac20h32o2molar mass304.474 g·mol−13d model (jsmol)interactive image smiles c1c2((cc32cc4(3cc4o)c)cc1=o)c inchi inchi=1s/c20h32o2/c1-12-11-20(3)13(10-17(12)21)4-5-14-15-6-7-18(22)19(15,2)9-8-16(14)20/h12-16,18,22h,4-11h2,1-3h3/t12-,13+,14+,15+,16+,18+,19+,20+/m1/s1 nkey:ikxildnpczpprv-rfmgovqksa-n n ny (what is this?) (verify) pharmacology pharmacodynamics androgenic vs. anabolic activityof androgens/anabolic steroids medicationratioa testosterone~1:1 androstanolone (dht)~1:1 methyltestosterone~1:1 methandriol~1:1 fluoxymesterone1:1–1:15 metandienone1:1–1:8 drostanolone1:3–1:4 metenolone1:2–1:30 oxymetholone1:2–1:9 oxandrolone1:3–1:13 stanozolol1:1–1:30 nandrolone1:3–1:16 ethylestrenol1:2–1:19 norethandrolone1:1–1:20 notes: in rodents. footnotes: a = ratio of androgenic to anabolic activity. sources: see template. like other aas, drostanolone is an agonist of the androgen receptor (ar). it is not a substrate for 5α-reductase and is a poor substrate for 3α-hydroxysteroid dehydrogenase (3α-hsd), and therefore shows a high ratio of anabolic to androgenic activity. as a dht derivative, drostanolone is not a substrate for aromatase and hence cannot be aromatized into estrogenic metabolites. while no data are available on the progestogenic activity of drostanolone, it is thought to have low or no such activity similarly to other dht derivatives. since the drug is not 17α-alkylated, it is not known to cause hepatotoxicity. chemistry