Estradiol (medication)
Estradiol is available in a variety of different formulations, including oral, intranasal, transdermal/topical, vaginal, injectable, and implantable preparations. An ester may be attached to one or both of the hydroxyl groups of estradiol to improve its oral bioavailability and/or duration of action with injection. Such modifications give rise to forms such as estradiol acetate (oral and vaginal), estradiol valerate (oral and injectable), estradiol cypionate (injectable), estradiol benzoate (injectable), estradiol undecylate (injectable), and polyestradiol phosphate (injectable; a polymerized ester of estradiol), which are all prodrugs of estradiol.
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.