dimethylstilbestrol dimethylstilbestrol dimethylstilbestrol (dms) is a nonsteroidal estrogen of the stilbestrol group related to diethylstilbestrol which was never marketed. it is a so-called "weak", "impeded", or "short-acting" estrogen similarly to estriol and meso-butoestrol. the affinity of dms for the er was reported as about 10% of that of estradiol. for comparison, diethylstilbestrol had 140% of the affinity of estradiol for the er. not to be confused with diethylstilbestrol or dimestrol. dimethylstilbestrolclinical dataother namesdms; (ε)-α,α'-dimethyl-4,4'-stilbenedioldrug classnonsteroidal estrogenidentifiers iupac name 4-phenol cas number552-80-7 13366-36-4pubchem cid3004636chemspider2274931unii30l22q8n9mkeggc14234chebichebi:34717chemblchembl269003comptox dashboard (epa)dtxsid2022468 chemical and physical dataformulac16h16o2molar mass240.302 g·mol−13d model (jsmol)interactive image smiles c/c(=c(/c)\c1=cc=c(c=c1)o)/c2=cc=c(c=c2)o inchi inchi=1s/c16h16o2/c1-11(13-3-7-15(17)8-4-13)12(2)14-5-9-16(18)10-6-14/h3-10,17-18h,1-2h3/b12-11+key:xpinipxarsnzdm-vawyxsnfsa-n the endometrial proliferation dose of dms in women is 20 mg. a single 12 mg intramuscular injection of dms has a duration of approximately 12 days in humans.