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.
Pharmacodynamics of estradiol
Estradiol is an estrogen, or an agonist of the nuclear estrogen receptors (ERs), the estrogen receptor alpha (ERα) and the estrogen receptor beta (ERβ). According to one study, the value of estradiol for the human ERα is 50 pM (0.05 nM) and for the human ERβ is 200 pM (0.2 nM). Estradiol is also an agonist of the membrane estrogen receptors (mERs), including the G protein-coupled estrogen receptor (GPER), G-coupled membrane estrogen receptor (G-mER), ER-X, and ERx. It is far more potent as an estrogen than are other natural and bioidentical estrogens like estrone and estriol. Given by subcutaneous injection in mice, estradiol is about 10-fold more potent than estrone and about 100-fold more potent than estriol.