methallenestril methallenestril methallenestril (inn) (brand names cur-men, ercostrol, geklimon, novestrine, vallestril), also known as methallenoestril (ban) and as methallenestrol, as well as horeau's acid, is a synthetic nonsteroidal estrogen and a derivative of allenolic acid and allenestrol (specifically, a methyl ether of it) that was formerly used to treat menstrual issues but is now no longer marketed. it is a seco-analogue of bisdehydrodoisynolic acid, and although methallenestril is potently estrogenic in rats, in humans it is only weakly so in comparison. vallestril was a brand of methallenestril issued by g. d. searle & company in the 1950s. methallenestril is taken by mouth. by the oral route, a dose of 25 mg methallenestril is approximately equivalent to 1 mg diethylstilbestrol, 4 mg dienestrol, 20 mg hexestrol, 25 mg estrone, 2.5 mg conjugated estrogens, and 0.05 mg ethinylestradiol. methallenestrilclinical datatrade namescur-men, ercostrol, geklimon, novestrine, vallestril (also spelled vallestrol or vallestryl)other namesmethallenoestril; methallenestrol; methallenoestrol; horeau's acid; allenestrol 6-methyl ether; α,α-dimethyl-β-ethylallenolic acid 6-methyl ether; β-ethyl-6-methoxy-α,α-dimethyl-2-naphthalenepropionic acidroutes ofadministrationby mouthdrug classnonsteroidal estrogenatc codeg03cb03 (who) g03cc03 (who)identifiers iupac name 3-(6-methoxynaphthalen-2-yl)-2,2-dimethylpentanoic acid cas number517-18-0pubchem cid10599chemspider10154uniixl025389jscomptox dashboard (epa)dtxsid7023275 echa infocard100.007.485 chemical and physical dataformulac18h22o3molar mass286.371 g·mol−13d model (jsmol)interactive image smiles ccc(c1ccc2cc(oc)ccc2c1)c(c)(c)c(=o)o inchi inchi=1s/c18h22o3/c1-5-16(18(2,3)17(19)20)14-7-6-13-11-15(21-4)9-8-12(13)10-14/h6-11,16h,5h2,1-4h3,(h,19,20)key:khljkrbmzvnzoc-uhfffaoysa-n (verify)