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).
Estrone (medication)
Although estrone has been widely marketed in the past, it has mostly been discontinued and remains available in only a few countries. These countries reportedly include Canada, Georgia, Monaco, and Taiwan. However, estrone remains widely available throughout the world in the form of estrone sulfate, which can be found in estropipate (piperazine estrone sulfate), conjugated estrogens (Premarin), and esterified estrogens (Estratab, Menest).