11α-hydroxyprogesterone 11α-hydroxyprogesterone 11α-hydroxyprogesterone (11α-ohp), or 11α-hydroxypregn-4-ene-3,20-dione is an endogenous steroid and metabolite of progesterone. it is a weak antiandrogen, and is devoid of androgenic, estrogenic, and progestogenic activity. not to be confused with 17α-hydroxyprogesterone. 11α-hydroxyprogesteroneclinical dataother names11α-ohp; 11α-hydroxypregn-4-ene-3,20-dione; 4-pregnen-11α-ol-3,20-dione; δ4-pregnen-11α-ol-3,20-dioneidentifiers iupac name (8s,9s,10r,11r,13s,14s,17s)-17-acetyl-11-hydroxy-10,13-dimethyl-1,2,6,7,8,9,11,12,14,15,16,17-dodecahydrocyclopentaphenanthren-3-one cas number80-75-1 ypubchem cid92730chemspider83709uniid8x4jxl4vmchebichebi:16076chemblchembl1563246echa infocard100.001.189 chemical and physical dataformulac21h30o3molar mass330.468 g·mol−13d model (jsmol)interactive image smiles cc(=o)c1ccc2c1(cc(c3c2ccc4=cc(=o)ccc34c)o)c inchi inchi=1s/c21h30o3/c1-12(22)16-6-7-17-15-5-4-13-10-14(23)8-9-20(13,2)19(15)18(24)11-21(16,17)3/h10,15-19,24h,4-9,11h2,1-3h3/t15-,16+,17-,18+,19+,20-,21+/m0/s1key:bfzhcubiasxhpk-qjskaatbsa-n 11α-ohp was investigated as a topical antiandrogen for the treatment of androgen-dependent skin conditions in the early 1950s, and was found to produce some benefit. in 1995, 11α-ohp, along with its epimer 11β-hydroxyprogesterone, was identified as a very potent competitive inhibitor of both isoforms (1 and 2) of 11β-hydroxysteroid dehydrogenase (11β-hsd). it is notably not metabolized by 11β-hsd2. 11α-ohp is a more potent inhibitor of 11β-hsd than enoxolone (glycyrrhetinic acid) or carbenoxolone in vitro (ic50 = 0.9 nm; ic50 = 5 nm in transfected cells). the compound has been found to be highly active in conferring mineralocorticoid sodium-retaining activity of corticosterone in vivo in rat bioassays and in increasing blood pressure, effects that it mediates by preventing the 11β-hsd-mediated inactivation of endogenous corticosteroids. because of its inhibition of 11β-hsd and consequent potentiation of corticosteroids, 11α-ohp has recently been patented for the treatment of skin diseases, particularly psoriasis in combination with clobetasol propionate and minoxidil. 11α-ohp is used as a precursor in chemical syntheses of cortisone and hydrocortisone.