Updated statement on Levonorgestrel ECPs' Mechanism of Action
12th April 2011
The International Conortium for Emergency Contraception (ICEC), in collaboration with the International Federation of Gynecology and Obstetrics (FIGO), has updated its statement How do Levonorgestrel-only emergency contraceptive pills (LNG ECPs) work to prevent pregnancy?.
The revised statement is based on an extensive review of the recent literature, and concludes that "...inhibition or delay of ovulation is LNG ECPs’ principal and possibly only mechanism of action. LNG ECPs cannot prevent implantation of a fertilized egg".