Starting in the 1950s, ethinylestradiol became widely used in birth control pills. Estradiol-containing birth control pills were initially studied in the 1970s, with the first report published in 1977. Development of birth control pills containing estradiol was motivated by the thrombotic risks of ethinylestradiol that were uncovered in the 1960s and 1970s. More than 15 attempts were made at development of an estradiol-containing birth control pill starting in the 1970s, but were unsuccessful due to unacceptable menstrual bleeding patterns. Estradiol valerate/cyproterone acetate (Femilar) was introduced for use as a birth control pill in Finland in 1993, but was never marketed elsewhere. Subsequently, estradiol valerate/dienogest (Natazia, Qlaira) was marketed as a birth control pill in 2008 and estradiol/nomegestrol acetate (Naemis, Zoely) was introduced in 2012. Society and culture
Generic names
Estradiol is the generic name of estradiol in American English and its INN, USAN, USP, BAN, DCF, and JAN. Estradiolo is the name of estradiol in Italian and the DCIT and estradiolum is its name in Latin, whereas its name remains unchanged as estradiol in Spanish, Portuguese, French, and German. Oestradiol was the former BAN of estradiol and its name in British English, but the spelling was eventually changed to estradiol. When estradiol is provided in its hemihydrate form, its INN is estradiol hemihydrate. Brand names
Estradiol is marketed under a large number of brand names throughout the world.
Older age, higher body weight, lower physical activity, and smoking are all associated with a higher risk of VTE with oral estrogen therapy. Risk of VTE with estrogen therapy is highest at the start of treatment, particularly during the first year, and decreases over time.The absolute risk of VTE with estrogen and/or progestin therapy is small. Women who are not on a birth control pill or hormone therapy have a risk of VTE of about 1 to 5 out of 10,000 women per year. In women taking a birth control pill containing ethinylestradiol and a progestin, the risk of VTE is in the range of 3 to 10 out of 10,000 women per year. Birth control pills containing estradiol valerate and a progestin are associated with about half the risk of VTE of ethinylestradiol/progestin-containing birth control pills. Hormone therapy for transgender women likewise is associated with a lower risk of VTE than birth control pills containing ethinylestradiol and a progestin. The risk of VTE during pregnancy, when estrogens and progesterone increase to very high levels, is 5 to 20 in 10,000 women per year, while the risk is 40 to 65 per 10,000 women per year during the postpartum period. Long-term effects
Uncommon but serious possible side effects of estrogens associated with long-term therapy may include breast cancer, uterine cancer, stroke, heart attack, blood clots, dementia, gallbladder disease, and ovarian cancer.