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)
A variety of analogues of estriol are known, including both naturally occurring isomers and synthetic substituted derivatives and esters. 16β-Epiestriol (epiestriol), 17α-epiestriol, and 16β,17α-epiestriol are isomers of estriol that are endogenous weak estrogens. Mytatrienediol (16α-methyl-16β-epiestriol 3-methyl ether) is a synthetic derivative of 16β-epiestriol that was never marketed. Estriol acetate benzoate, estriol succinate, and estriol tripropionate are synthetic estriol esters that have been marketed for medical use, whereas estriol dihexanoate, estriol dipropionate, and estriol triacetate have not been introduced. Quinestradol is the 3-cyclopentyl ether of estriol and has also been marketed. Polyestriol phosphate, an ester of estriol in the form of a polymer, has been marketed previously as well. These esters, ethers, and polymers are prodrugs of estriol. Ethinylestriol and nilestriol are synthetic C17α ethynylated derivatives of estriol. Ethinylestriol has not been marketed, but nilestriol, which is the 3-cyclopentyl ether of ethinylestriol and a prodrug of it, has been.