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Birth Control Hormones: The Pill

Overview

What are combination pills for birth control?

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.

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.

How well do combination pills work?

In the first year of use:

  • When combination pills are taken exactly as directed, they are more than 99% effective at preventing pregnancy. That means that fewer than 1 out of 100 people will have an unplanned pregnancy.
  • When pills are not taken exactly as directed, such as when they are sometimes missed, they are 93% effective at preventing pregnancy. That means that 7 out of 100 people will have an unplanned pregnancy.

What should you think about when using combination pills?

Some pros of using the pill

  • These pills work better than barrier methods, such as 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.

Some cons of using the pill

  • 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. You can use a condom to reduce your risk of getting an STI.
  • 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 or less interest in sex.
  • Combination pills contain estrogen. They may not be right for you if you have certain health problems.

Credits

Current as of: May 5, 2025

Author: Ignite Healthwise, LLC Staff
Clinical Review Board
All Ignite Healthwise, LLC education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

This information does not replace the advice of a doctor. Ignite Healthwise, LLC, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.

© 2024-2026 Ignite Healthwise, LLC.

This information does not replace the advice of a doctor. Ignite Healthwise, LLC, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.

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