estriol dipropionate estriol dipropionate estriol dipropionate, or estriol 3,17β-dipropionate, is a synthetic estrogen and estrogen ester – specifically, the c3 and c17β dipropionate ester of estriol – which was first described in 1963 and was never marketed. following a single intramuscular injection of 6.94 mg estriol dipropionate (equivalent to 5.0 mg estriol) in an oil solution, peak levels of estriol occurred after 0.83 days, an elimination half-life of 12.7 hours was observed, and estriol levels remained elevated for up to 4 days. for comparison, the duration of estriol was much shorter, while that of estriol dihexanoate was much longer. estriol dipropionateclinical dataother namesoestriol dipropionate; estriol 3,17β-dipropionate; 16α-hydroxyestra-1,3,5(10)-triene-3,17β-diyl dipropanoateroutes ofadministrationintramuscular injectiondrug classestrogen; estrogen esteridentifiers iupac name phenanthren-17-yl] propanoate cas number104202-88-2 ypubchem cid128508chemspider113905uniiayw6g49m3schemical and physical dataformulac24h32o5molar mass400.515 g·mol−13d model (jsmol)interactive image smiles ccc(=o)o1(c21(cc32ccc4=c3c=cc(=c4)oc(=o)cc)c)o inchi inchi=1s/c24h32o5/c1-4-21(26)28-15-7-9-16-14(12-15)6-8-18-17(16)10-11-24(3)19(18)13-20(25)23(24)29-22(27)5-2/h7,9,12,17-20,23,25h,4-6,8,10-11,13h2,1-3h3/t17-,18-,19+,20-,23+,24+/m1/s1key:qkldceyhdkpvdk-priymhjnsa-n