Estradiol stearate
Estradiol stearate (brand name Depofollan), or estradiol octadecanoate, is a naturally occurring steroidal estrogen and an estrogen ester – specifically, the C17β stearate ester of estradiol. It occurs in the body as a very long-lasting metabolite and prohormone of estradiol. In addition, estradiol stearate is or has been available as a pharmaceutical drug for use via depot intramuscular injection. The drug was introduced in 1941 as Depofollan and was the first long-acting estrogen, although it has never been widely used. It has been reported in at least one source to have a duration of at least one month.
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.