How It Work

1. They stop ovulation

Most birth control pills prevent the ovaries from releasing an egg each month. Without an egg, sperm cannot fertilize anything.

2. They thicken cervical mucus

The hormones make the mucus at the cervix thicker and stickier, making it harder for sperm to enter the uterus and reach an egg.

3. They change the uterine lining

The pills make the lining of the uterus (endometrium) thinner, making it less suitable for implantation if fertilization were to occur.