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 (medication)
Estriol is available in oral tablet, vaginal cream, and vaginal suppository forms. It is also available over-the-counter or from compounding pharmacies in the form of topical creams. The medication is available both as estriol and in the form of estriol ester prodrugs such as estriol succinate, estriol acetate benzoate, and estriol tripropionate.