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.
Estrone (medication)
Although estrone has been widely marketed in the past, it has mostly been discontinued and remains available in only a few countries. These countries reportedly include Canada, Georgia, Monaco, and Taiwan. However, estrone remains widely available throughout the world in the form of estrone sulfate, which can be found in estropipate (piperazine estrone sulfate), conjugated estrogens (Premarin), and esterified estrogens (Estratab, Menest).