Hormonal Methods

Hormonal methods work in different ways depending on the method being used. The two main ways that hormonal methods prevent pregnancy are:

1. They keep eggs from leaving the ovary.
2. They thicken the mucus made in the cervix so that sperm can't travel through it to get to the egg. (The cervix is the bottom part of the uterus that is at the back of the vagina.)

Some hormonal methods may work by causing the lining of the uterus to thin, which may prevent the fertizilized egg from attaching to it and growing. However, the chance of a method working in this way is very unlikely.

The hormones in these methods are very much like the hormones estrogen and progesterone that are made naturally in every woman's body. Estrogen and progesterone are chemicals made in the ovaries that send special messages to the other parts of a woman's body to prepare it for the possibility of becoming pregnant. However, when hormonal birth control methods are used, they stop the woman's body from making the right amount of these hormones. This causes changes in the woman's body that stop her from becoming pregnant.

Hormonal methods work very well to prevent pregnancy, but do not protect against HIV or other sexually transmitted diseases. If a woman is concerned that she might get a sexually transmitted disease from her partner, the couple should use condoms.