Birth Control Hormones: The Pill

Overview

Combination pills are used to prevent pregnancy. Most people call them "the pill."

Combination pills release a regular dose of two hormones, estrogen and progestin. They prevent pregnancy in a few ways. They thicken the mucus in the cervix. This makes it hard for sperm to travel into the uterus. And they thin the lining of the uterus. This makes it harder for a fertilized egg to attach to the uterus.

The hormones also can stop the ovaries from releasing an egg each month (ovulation).

You have to take a pill every day to prevent pregnancy.

The packages for these pills are different. The most common one has 3 weeks of hormone pills and 1 week of sugar pills. The sugar pills don't contain any hormones. You have your period on that week. But other packs have no sugar pills. You take hormone pills for the whole month instead. This is called continuous use. With this method, you will not get your period as often. Or you may not get it at all.

How well do they work?

In the first year of use:

• When combination pills are taken exactly as directed, fewer than 1 person out of 100 has an unplanned pregnancy.
• When pills are not taken exactly as directed, such as forgetting to take them sometimes, 9 people out of 100 have an unplanned pregnancy.

Be sure to tell your doctor about any health problems you have or medicines you take. Your doctor can help you choose the birth control method that is right for you.

What are the advantages of using combination pills for birth control?

• These pills work better than barrier methods. Barrier methods include condoms and diaphragms.
• They may reduce acne and heavy bleeding. They may also reduce cramping and other symptoms of PMS (premenstrual syndrome).
• The pills let you control your periods. You can schedule your periods to be every month or every few months. Or you can choose not to have them at all. You may take pills that continue to give you hormones during the whole month (continuous use). This protects against pregnancy and is also a safe way to avoid having your period. This may help if you have painful periods.
• You don't have to interrupt sex to use the pills.

What are the disadvantages of using combination pills for birth control?

• You have to take a pill at the same time every day to prevent pregnancy.
• Combination pills don't protect against sexually transmitted infections (STIs), such as herpes or HIV/AIDS. If you aren't sure if your sex partner(s) might have an STI, use a condom to help protect against disease.
• They may cause changes in your period. You may have little bleeding, skipped periods, or spotting. If you're using pills that give you hormones for the whole month, your periods will stop. But you may still have breakthrough bleeding. This usually isn't harmful and may decrease over time.
• They may cause mood changes, less interest in sex, or weight gain.
• Combination pills contain estrogen. They may not be right for you if you have certain health problems.