estradiol undecylate http://purl.obolibrary.org/obo/CHEBI_135719 https://en.wikipedia.org/wiki/Estradiol_undecylate https://www.wikidata.org/wiki/Q5401764 An estrogen medication which has been used in the treatment of prostate cancer in cisgender men. It has also been used as a part of hormone therapy for transgender women. Although estradiol undecylate has been used in the past, it was discontinued and hence is no longer available. The medication has been given by injection into muscle usually once a month. EU estradiol estradiol ester