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.
Cloxestradiol acetate
Cloxestradiol acetate (brand name Genovul), also known as 17-(2,2,2-trichloroethoxy)estradiol "O","O"-diacetate, is a synthetic, steroidal estrogen derived from estradiol. It is the "O","O"-diacetate ester of cloxestradiol, which, in contrast to cloxestradiol acetate, was never marketed.