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).
Estriol (medication)
Following its discovery in 1930, estriol was introduced for medical use as an oral tablet in the 1930s. Emmenin and Progynon were oral estrogens that contained estriol conjugates, primarily estriol glucuronide, and were introduced in the 1930s. They were the first orally active estrogen preparations to be introduced in medicine. Estriol continues to be used medically today, widely throughout the world and in a variety of different formulations and brand names.