Estradiol diundecylate (brand name Estrolent), or estradiol diundecanoate, also known as 17ò-estradiol 3,17ò-diundecylate, is an estrogen and an estrogen ester â specifically, the 3,17ò-diundecylate ester of estradiol â which has been marketed in Romania. It was described, along with a variety of other estradiol esters such as estradiol undecylate, by Karl Junkmann of Schering AG in 1953.