What is the pharmacological effect of emergency contraception?

Emergency contraception works by preventing or delaying ovulation, fertilization, or implantation of a fertilized egg in the uterus. It may also thicken cervical mucus to prevent sperm from reaching an egg. The exact mechanism of action can vary depending on the type of emergency contraception used. Overall, the goal is to prevent an unintended pregnancy after unprotected sex or contraceptive failure.