<unk>  (E2-EN or EEn), also spelled<unk>  and sold under the brand names Perlutal and Topasel among others, is an estrogen medication which is used in hormonal birth control for women. It is formulated in combination with dihydroxyprogesterone acetophenide (DHPA; algestone acetophenide), a progestin, and is used specifically as a combined injectable contraceptive.<unk>  is not available for medical use alone. The medication, in combination with DHPA, is given by injection into muscle once a month. Side effects of<unk>  include breast tenderness, breast enlargement, nausea, headache, and fluid retention.<unk>  is a synthetic estrogen and hence is an agonist of the estrogen receptor, the biological target of estrogens like estradiol. It is an estrogen ester and a long-lasting prodrug of estradiol in the body. Because of this, it is considered to be a natural and bioidentical form of estrogen.<unk>  was first described by 1954, and was first studied in combination with DHPA as a combined injectable contraceptive in 1964. The combination was introduced for clinical use by the mid-1970s.<unk>  is not available as a standalone medication (i.e., by itself without DHPA). The combination is available in Latin America and Hong Kong, and was also previously marketed in Spain and Portugal.
Estradiol enantate
Estradiol undecylate
Estradiol dienantate
Estradiol furoate
Estradiol valerate
Hexestrol diphosphate
Estradiol dipropionate
Estradiol cypionate