Levonorgestrel-releasing implant, sold under the brand name Jadelle among others, are devices that release levonorgestrel for birth control. It is one of the most effective forms of birth control with a one-year failure rate around 0.05%. The device is placed under the skin and lasts for up to five years. It may be used by women who have a history of pelvic inflammatory disease and therefore cannot use an intrauterine device. Following removal fertility quickly returns. It is generally well tolerated with few significant side effects. Side effects may include irregular menstrual periods, no periods, headaches, and breast pain. Use is not recommended in people with significant liver disease. The levonorgestrel implant is a type of long-acting reversible birth control. It primarily works by stopping ovulation and by thickening the mucus around the cervix. A levonorgestrel-releasing implant was approved for medical use in 1983 in Finland and in the United States in 1990. It is on the World Health Organization's List of Essential Medicines. Levonorgestrel implants are approved in more than 60 countries and used by more than seven million women. As of 2015 it is approved but not available in the United States. Medical uses Levonorgestrel-releasing implant is 99–99.95% effective at preventing pregnancy, and is one of the most reliable, though not the most available, forms of birth control. Levonorgestrel-releasing implant prevents pregnancy through multiple methods: by preventing ovulation, which means that no eggs are released for fertilization; by thickening the mucus of the cervix, which prevents sperm from entering; and by thinning the lining of the uterus, which makes implantation of an embryo less likely. The way in which levonorgestrel-releasing implant causes these effects is by use of hormones. A small amount of the hormone progestin is released through the capsules continuously, more during the first year and a half, but then at a level similar to most contraceptive pills afterward. Like all hormonal contraception, levonorgestrel-releasing implant does not protect against sexually transmitted infections. Implantable contraceptives are especially effective in the developing world, as they do not require daily administration or access to a hospital to be effective. In addition, no continual contraceptive supplies (pills, condoms, etc.) are necessary, and it is a highly effective, low cost contraceptive over the long term. Contraindications Levonorgestrel-releasing implant should not be used in women with liver disease, breast cancer, or blood clots. Women who believe they may already be pregnant or