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 (medication)
Estrogens are involved in breast development and estradiol may be used as a form of hormonal breast enhancement to increase the size of the breasts. Both pseudopregnancy with a combination of high-dosage intramuscular estradiol valerate and hydroxyprogesterone caproate and polyestradiol phosphate monotherapy have been assessed for this purpose in clinical studies. However, acute or temporary breast enlargement is a well-known side effect of estrogens, and increases in breast size tend to regress or disappear entirely following discontinuation of treatment. Aside from in those without prior established breast development, evidence is lacking for long-term or sustained increases in breast size with estrogens.