ethisterone ethisterone ethisterone, also known as ethinyltestosterone, pregneninolone, and anhydrohydroxyprogesterone and formerly sold under the brand names proluton c and pranone among others, is a progestin medication which was used in the treatment of gynecological disorders but is now no longer available. it was used alone and was not formulated in combination with an estrogen. the medication is taken by mouth. "pregneninolone" redirects here. for the similarly named steroid, see pregnenolone. ethisteroneclinical datatrade namesproluton c, pranone, othersother namesethinyltestosterone; ethynyltestosterone; pregneninolone; anhydrohydroxyprogesterone; etisteron; pregnin; ethindroneroutes ofadministrationby mouth, sublingualdrug classprogestogen; progestin; androgen; anabolic steroidatc codeg03dc04 (who) pharmacokinetic datametabolites• 5α-dihydroethisteroneidentifiers iupac name (8r,9s,10r,13r,14s,17r)-17-ethynyl-17-hydroxy-10,13-dimethyl-2,6,7,8,9,11,12,14,15,16-decahydro-1h-cyclopentaphenanthren-3-one cas number434-03-7 ypubchem cid5284557chemspider4447612 yuniip201bvy1mjchebichebi:34749 ychemblchembl241694 ycomptox dashboard (epa)dtxsid2023016 echa infocard100.006.452 chemical and physical dataformulac21h28o2molar mass312.453 g·mol−13d model (jsmol)interactive image smiles c12ccc(=o)c=c1cc32cc4(3cc4(c#c)o)c inchi inchi=1s/c21h28o2/c1-4-21(23)12-9-18-16-6-5-14-13-15(22)7-10-19(14,2)17(16)8-11-20(18,21)3/h1,13,16-18,23h,5-12h2,2-3h3/t16-,17+,18+,19+,20+,21+/m1/s1 ykey:chnxzkvnwqujib-cegnmafcsa-n y (verify) side effects of ethisterone include masculinization among others. ethisterone is a progestin, or a synthetic progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone. it has some androgenic and anabolic activity and no other important hormonal activity. ethisterone was discovered in 1938 and was introduced for medical use in germany in 1939 and in the united states in 1945. it was the second progestogen to be marketed, following injected progesterone in 1934, and was both the first orally active progestogen and the first progestin to be introduced. ethisterone was followed by the improved and much more widely used and known progestin norethisterone in 1957. medical uses ethisterone was used in the treatment of gynecological disorders such as irregular menstruation, amenorrhea, and premenstrual syndrome. available forms ethisterone was available in the form of 5, 10, and 25 mg oral and sublingual tablets, as well as 50 , 100 , and 250 mg oral capsules. the usual dosage was 25 mg, up to four times per day. side effects