norethindrone

Norethisterone

Norethisterone, also known as norethindrone and sold under the brand name Norlutin among others, is a progestin medication used in birth control pills, menopausal hormone therapy, and for the treatment of gynecological disorders. The medication is available in both low-dose and high-dose formulations and both alone and in combination with an estrogen. It is used by mouth or, as norethisterone enanthate, by injection into muscle. Side effects of norethisterone include menstrual irregularities, headaches, nausea, breast tenderness, mood changes, acne, increased hair growth. Norethisterone is a progestin, or a synthetic progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone. It has weak androgenic and estrogenic activity, mostly at high dosages, and no other important hormonal activity. Norethisterone was discovered in 1951 and was one of the first progestins to be developed. It was first introduced for medical use on its own in 1957 and was introduced in combination with an estrogen for use as a birth control pill in 1963. It is sometimes referred to as a "first-generation" progestin. Like desogestrel and Norgestrel, Norethisterone is available as a progestogen-only "mini pill" for birth control. Norethisterone is marketed widely throughout the world. It is available as a generic medication. In 2023, it was the 136th most commonly prescribed medication in the United States, with more than 4 million prescriptions. It is on the World Health Organization's List of Essential Medicines.