Levonorgestrel

Levonorgestrel is a progestin hormone that is commonly used in contraceptive medications. It works by preventing ovulation, which is the release of an egg from the ovary, and also thickening the cervical mucus, which makes it more difficult for sperm to reach an egg. Levonorgestrel is a synthetic version of the natural hormone progesterone, and it is widely used in various contraceptive methods, such as emergency contraception, intrauterine devices (IUDs), and birth control pills.
In emergency contraception, also known as the “morning-after pill,” levonorgestrel is used to prevent pregnancy after unprotected sex or contraceptive failure. It is most effective when taken as soon as possible after the incident but can still be effective up to 72 hours later. It works by preventing or delaying ovulation and, in some cases, by preventing fertilization or implantation of a fertilized egg.
Intrauterine devices (IUDs) that contain levonorgestrel are highly effective long-acting reversible contraceptives (LARCs) that can prevent pregnancy for several years. These IUDs work primarily by thickening cervical mucus, inhibiting sperm movement, and in some cases, by preventing implantation of a fertilized egg. The levonorgestrel IUD is also effective in managing heavy menstrual bleeding and reducing pain associated with endometriosis and pelvic inflammatory disease.
Levonorgestrel is also used in combination with other hormones, such as ethinylestradiol, in birth control pills to prevent pregnancy. The combination of hormones works by suppressing ovulation and preventing fertilization, as well as altering the uterine lining to make it less receptive to a fertilized egg. Birth control pills containing levonorgestrel are available in various formulations and dosages, which can be tailored to individual needs and preferences.