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.
Dienestrol
Dienestrol (, ) (brand names Ortho Dienestrol, Dienoestrol, Dienoestrol Ortho, Sexadien, Denestrolin, Dienol, Dinovex, Follormon, Oestrodiene, Synestrol, numerous others), also known as dienoestrol (), is a synthetic nonsteroidal estrogen of the stilbestrol group which is or was used to treat menopausal symptoms in the United States and Europe. It has been studied for use by rectal administration in the treatment of prostate cancer in men as well. The medication was introduced in the U.S. in 1947 by Schering as Synestrol and in France in 1948 as Cycladiene. Dienestrol is a close analogue of diethylstilbestrol. It has approximately 223% and 404% of the affinity of estradiol at the ERα and ERβ, respectively.