Estrogen (medication)
Estradiol, estrone, and estriol have all been approved as pharmaceutical drugs and are used medically. Estetrol is currently under development for medical indications, but has not yet been approved in any country. A variety of synthetic estrogen esters, such as estradiol valerate, estradiol cypionate, estradiol acetate, estradiol benzoate, estradiol undecylate, and polyestradiol phosphate, are used clinically. The aforementioned compounds behave as prodrugs to estradiol, and are much longer-lasting in comparison when administered by intramuscular or subcutaneous injection. Esters of estrone and estriol also exist and are or have been used in clinical medicine, for example estrone sulfate (e.g., as estropipate), estriol succinate, and estriol glucuronide (as Emmenin and Progynon).
Estriol succinate
Estriol succinate, also known as estriol disuccinate or as estriol 16α,17β-di(hydrogen succinate), is a synthetic estrane steroid and a derivative of estriol. It is specifically the C16α and C17β disuccinate ester of estriol. The medication is provided both as estriol succinate and as estriol sodium succinate, the sodium salt. Other marketed estriol esters besides estriol succinate include estriol acetate benzoate and estriol tripropionate, whereas estriol dihexanoate, estriol dipropionate, and estriol triacetate are estriol esters that were never marketed. Quinestradol is an estriol ether and has also been marketed. Polyestriol phosphate is an ester of estriol in the form of a polymer, and was previously marketed.