etynodiol etynodiol etynodiol, or ethynodiol, is a steroidal progestin of the 19-nortestosterone group which was never marketed. a diacylated derivative, etynodiol diacetate, is used as a hormonal contraceptive. etynodiol is sometimes used as a synonym for etynodiol diacetate. etynodiolclinical dataother namesethynodiol; 3β-hydroxynorethisterone; 17α-ethynylestr-4-ene-3β,17β-dioldrug classprogestin; progestogenatc codeg03dc06 (who) identifiers iupac name (3s,8r,9s,10r,13s,14s,17r)-17-ethynyl-13-methyl-2,3,6,7,8,9,10,11,12,14,15,16-dodecahydro-1h-cyclopentaphenanthrene-3,17-diol cas number1231-93-2chemspider14017unii9e01c36a9scomptox dashboard (epa)dtxsid1023025 echa infocard100.013.610 chemical and physical dataformulac20h28o2molar mass300.442 g·mol−13d model (jsmol)interactive image smiles o4/c=c3\(2cc1((cc1(c#c)o)2cc3)c)cc4 inchi inchi=1s/c20h28o2/c1-3-20(22)11-9-18-17-6-4-13-12-14(21)5-7-15(13)16(17)8-10-19(18,20)2/h1,12,14-18,21-22h,4-11h2,2h3/t14-,15-,16+,17+,18-,19-,20-/m0/s1key:jyilperkvhxlnf-qmnutnmbsa-n it was patented in 1955. pharmacology etynodiol is a prodrug of norethisterone, and is converted immediately and completely into norethisterone. etynodiol is an intermediate in the conversion of the prodrug lynestrenol into norethisterone. relative affinities (%) of norethisterone, metabolites, and prodrugs compoundtypeaprarergrmrshbgcbg norethisterone–67–751500–10–3160 5α-dihydronorethisteronemetabolite252700 ? ? ? 3α,5α-tetrahydronorethisteronemetabolite100–10 ? ? ? 3α,5β-tetrahydronorethisteronemetabolite ?00 ? ? ? ? 3β,5α-tetrahydronorethisteronemetabolite100–80 ? ? ? ethinylestradiolmetabolite15–251–31121–300.180 norethisterone acetateprodrug205100 ? ? norethisterone enanthateprodrug ? ? ? ? ? ? ? noretynodrelprodrug6020000 etynodiolprodrug1011–180 ? ? ? etynodiol diacetateprodrug10000 ? ? lynestrenolprodrug11300 ? ? notes: values are percentages (%). reference ligands (100%) were promegestone for the pr, metribolone for the ar, estradiol for the er, dexamethasone for the gr, aldosterone for the mr, dihydrotestosterone for shbg, and cortisol for cbg. footnotes: a = active or inactive metabolite, prodrug, or neither of norethisterone. sources: see template. chemistry