Pharmacokinetics of estradiol
Estradiol can be administered in the form of a very long-lasting subcutaneous pellet implant. These implants are replaced once every 6 to 12 months, and can achieve high and very constant circulating levels of estradiol. They are surgically inserted by a trained physician in a medical office or clinic and can be placed into locations including the lower abdomen, lower back, buttocks, or hips. Subcutaneous implants containing 25, 50, and 100 mg estradiol for replacement usually once every 6 months are available as approved pharmaceutical medications. Up to 800 mg estradiol per implantation has been used. Pharmaceutical estradiol implants have been said to be used almost exclusively in the United Kingdom. An estradiol implant has not been approved by the FDA as a pharmaceutical medication in the United States, but hormone implants, including estradiol implants, are available as custom compounded products in this country.
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.