Estradiol enantate
Estradiol enantate, sold under the brand names Perlutal and Topasel among others, is an estrogen medication which is used in hormonal birth control. It is formulated in combination with dihydroxyprogesterone acetophenide (DHPA; algestone acetophenide), a progestin, and is used as a combined injectable contraceptive. Estradiol enantate is not available alone. The medication is given by injection into muscle once a month.
Side effects of estradiol enantate include breast tenderness, breast enlargement, nausea, headache, and fluid retention. The drug is a synthetic estrogen and hence is an agonist of the estrogen receptor (ER), the biological target of estrogens like estradiol. Estradiol enantate is an estrogen ester and a long-lasting prodrug of estradiol in the body. Because of this, it is considered to be a natural and bioidentical form of estrogen.
Estradiol enantate was first described by 1954, and was first studied in combination with DHPA as a combined injectable contraceptive in 1964. The combination was introduced for clinical use by the mid-1970s. Estradiol enantate is not available as a standalone medication (i.e., by itself without DHPA). The combination is available in Latin America and Hong Kong, and was also previously marketed in Spain and Portugal.
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.