Birth control pills Levonorgestrel

today we will talk about Birth control pills Levonorgestrel
Levonorgestrel is a manufactured hormone used in a number of birth control methods.[1] In pill form, sold under the brand name Plan B among others, it is useful within 120 hours as emergency birth control. It becomes less effective the longer after sex and only works before pregnancy has occurred.
 It is also combined with an estrogen to make combined oral birth control pill. Within an IUD, sold as Mirena among others, it is effective for long term prevention of pregnancy.
 An implantable form of levonorgestrel is also available in some countries.

Common side effects include nausea, breast tenderness, headaches, and increased, decreased, or irregular menstrual bleeding. When used as a form of emergency contraception, if pregnancy occurs, there is no evidence its use harms the baby. It is safe to use during breastfeeding. Birth control that contains levonorgestrel will not change the risk of sexually transmitted infections. It works mostly by decreasing ovulation and closing off the cervix to prevent the passage of sperm.

Levonorgestrel was first made in the 1960s and its use as a method of birth control began in the 1980s.
 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.[6] The wholesale cost in the developing world costs between 0.23 and 1.65 USD for the dose required for emergency birth control.
 In the United States it is over the counter for all ages

Birth control pills
At low doses, levonorgestrel is used in monophasic and triphasic formulations of combined oral contraceptive pills, with available monophasic doses ranging from 100-250 µg, and triphasic doses of 50 µg/75 µg/125 µg.

At very low daily dose of 30 µg, levonorgestrel is used in some progestogen only pill formulations.