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.
Estradiol-containing birth control pill
Combined birth control pills that contain natural estradiol or an estradiol ester (e.g., estradiol valerate) include:It is hypothesized that these contraceptives may pose less of a risk of blood clots than contraceptives containing ethinylestradiol, which is the conventional estrogen that is used in oral contraceptives, but this has yet to be proven. However, incidence of irregular vaginal bleeding may be higher with estradiol-containing contraceptives in relation to the fact that estradiol is a weaker estrogen than ethinylestradiol in the endometrium.