Estradiol (medication)
Estradiol is also available in the U.S. in combination with progestogens for the treatment of menopausal symptoms and as a combined hormonal contraceptive:Estradiol and estradiol esters are also available in custom preparations from compounding pharmacies in the U.S. This includes subcutaneous pellet implants, which are not available in the United States as FDA-approved pharmaceutical drugs. In addition, topical creams that contain estradiol are generally regulated as cosmetics rather than as drugs in the U.S. and hence are also sold over-the-counter and may be purchased without a prescription on the Internet.
Estradiol (medication)
Estradiol was first isolated in 1935. It was also originally known as "dihydroxyestrin" or "alpha-estradiol". It was first marketed, as estradiol benzoate, in 1936. Estradiol was also marketed in the 1930s under brand names such as Progynon-DH, Ovocylin, and Dimenformon. Micronized estradiol, via the oral route, was first evaluated in 1972, and this was followed by the evaluation of vaginal and intranasal micronized estradiol in 1977. Oral micronized estradiol was first approved in the United States under the brand name Estrace in 1975.
In 1931, Butenandt found that the benzoic acid ester of estrone had a prolonged duration of action. Subsequently, Schwenk and Hildebrant synthesized estradiol benzoate from estradiol in 1933, and estradiol benzoate was introduced by Schering-Kahlbaum for medical use via intramuscular injection under the brand name Progynon-B in 1936. It was the first estrogen ester to be marketed, and has since been followed by many additional esters, for instance estradiol valerate and estradiol cypionate in the 1950s. Ethinylestradiol was synthesized from estradiol by Inhoffen and Hohlweg in 1938 and was introduced for oral use by Schering in the United States under the brand name Estinyl in 1943. It remains widely used in combined oral contraceptives.