Norgestrel
Norgestrel is a progestin which is used in birth control pills sold under the brand name Ovral in combination with the estrogen ethinylestradiol and Opill by itself. It is also used in menopausal hormone therapy. It is taken by mouth. Side effects of norgestrel include menstrual irregularities, headaches, nausea, and breast tenderness. The most common side effects of the progestin-only Opill include irregular bleeding, headaches, dizziness, nausea, increased appetite, abdominal pain, cramps, or bloating. Norgestrel 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 activity and no other important hormonal activity. Norgestrel was patented in 1961 and came into medical use, specifically in birth control pills, in 1966. It was subsequently introduced for use in menopausal hormone therapy as well. Norgestrel is sometimes referred to as a "second-generation" progestin. It is marketed widely throughout the world. Norgestrel is available as a generic medication. In 2020, the version with ethinylestradiol was the 316th most commonly prescribed medication in the United States, with more than 900 thousand prescriptions. In July 2023, the US Food and Drug Administration (FDA) approved norgestrel for over-the-counter sale. The FDA granted the approval to Laboratoire HRA Pharma which was acquired by Perrigo Company plc. Norgestrel is used in combination with ethinylestradiol or quinestrol in combined birth control pills, alone in progestogen-only birth control pills, and in combination with estradiol or conjugated estrogens in menopausal hormone therapy. It has also been used as an emergency contraceptive in the Yuzpe regimen. Levonorgestrel#Side effects and Progestin#Side effects Levonorgestrel#Pharmacodynamics Norgestrel is a progestogen, or an agonist of the progesterone receptor. The biological activity of norgestrel lies in the levo enantiomer, levonorgestrel, whereas the dextro isomer is inactive.