Estrogen (medication)
Estradiol, estrone, and estriol have all been approved as pharmaceutical drugs and are used medically. Estetrol is currently under development for medical indications, but has not yet been approved in any country. A variety of synthetic estrogen esters, such as estradiol valerate, estradiol cypionate, estradiol acetate, estradiol benzoate, estradiol undecylate, and polyestradiol phosphate, are used clinically. The aforementioned compounds behave as prodrugs to estradiol, and are much longer-lasting in comparison when administered by intramuscular or subcutaneous injection. Esters of estrone and estriol also exist and are or have been used in clinical medicine, for example estrone sulfate (e.g., as estropipate), estriol succinate, and estriol glucuronide (as Emmenin and Progynon).
Estradiol valerate
Estradiol valerate is and has been available in the form of vials and ampoules for intramuscular injection in concentrations of 5, 10, 20, and 40 mg/mL and in the form of oral tablets at doses of 0.5, 1, 2, and 4 mg per tablet. In the United States, it is specifically available in formulations of 10, 20, and 40 mg/mL (as Delestrogen, as well as generics). Aside from estradiol valerate, the only other injectable estrogen formulations that remain available in the United States are estradiol cypionate (5 mg/mL in oil) and conjugated estrogens (25 mg/vial in solution).