Estradiol (medication)
Estradiol is also widely available in combination with progestogens. It is available in combination with norethisterone acetate under the major brand names Activelle, Cliane, Estalis, Eviana, Evorel Conti, Evorel Sequi, Kliogest, Novofem, Sequidot, and Trisequens; with drospirenone as Angeliq; with dydrogesterone as Femoston, Femoston Conti; and with nomegestrol acetate as Zoely. Estradiol valerate is available with cyproterone acetate as Climen; with dienogest as Climodien and Qlaira; with norgestrel as Cyclo-Progynova and Progyluton; with levonorgestrel as Klimonorm; with medroxyprogesterone acetate as Divina and Indivina; and with norethisterone enantate as Mesigyna and Mesygest. Estradiol cypionate is available with medroxyprogesterone acetate as Cyclo-Provera, Cyclofem, Feminena, Lunelle, and Novafem; estradiol enantate with algestone acetophenide as Deladroxate and Topasel; and estradiol benzoate is marketed with progesterone as Mestrolar and Nomestrol.
Ethinylestradiol
Ethinylestradiol (EE) is an estrogen medication which is used widely in birth control pills in combination with progestins. It is also occasionally used as a component of menopausal hormone therapy for the treatment of menopausal symptoms in combination with progestins. In the past, EE was widely used alone for various indications such as the treatment of gynecological disorders and prostate cancer. It is usually taken by mouth.
The general side effects of EE include breast tenderness and enlargement, headache, fluid retention, and nausea among others. In men, EE can additionally cause breast development, feminization in general, hypogonadism, and sexual dysfunction. Rare but serious side effects include blood clots, liver damage, and cancer of the uterus.
EE is an estrogen, or an agonist of the estrogen receptors, the biological target of estrogens like estradiol. It is a synthetic derivative of estradiol, a natural estrogen, and differs from it in various ways. Compared to estradiol, EE has greatly improved bioavailability when taken by mouth, is more resistant to metabolism, and shows relatively increased effects in certain parts of the body like the liver and uterus. These differences make EE more favorable for use in birth control pills than estradiol, though also result in an increased risk of blood clots and certain other rare adverse effects.
EE was developed in the 1930s and was introduced for medical use in 1943. The drug started being used in birth control pills in the 1960s. Today, EE is found in almost all combined forms of birth control pills and is nearly the exclusive estrogen used for this purpose, making it one of if not the most widely used estrogens.