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.
Ethinylestradiol/levonorgestrel
Ethinylestradiol/levonorgestrel (also ethinyl estradiol/levonorgestrel) is a combined birth control pill made up of ethinylestradiol, an estrogen and levonorgestrel a progestin. It is used for birth control, symptoms of menstruation, endometriosis, and as emergency contraception. It is taken by mouth.
Side effects can include nausea, headache, blood clots, breast pain, depression, and liver problems. Use is not recommended during pregnancy, the initial three weeks after childbirth, and in those at high risk of blood clots. However, it may be started immediately after a miscarriage or abortion. Smoking while using combined birth control pills is not recommended. It works by stopping ovulation, making the mucus at the opening to the cervix thick, and making the uterus not suitable for implantation.
Ethinylestradiol/levonorgestrel has been approved for medical use in the United States at least since 1982. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. It is available as a generic medication. In the United Kingdom three months of medication costs the NHS about 1.80 pounds. In the United States it costs about $25–50 per month. It is marketed under a large number of brand names.