Birth Control Pills:

Side Effects

Intro	How to take BCP's
Side Effects	Frequently Asked Questions
Medical Benefits	Birth Control Myths
Who should NOT take BCP's

What are the possible side effects of birth control pills?

Most women have no side effects when taking the oral contraceptive pill. However, it is possible to have irregular periods, nausea, headaches, or weight change especially in the first few months. Each type of oral contraceptive pill can affect a young woman differently.

• Irregular periods: Spotting (you don't need to use a regular pad, just a panty shield) or very light bleeding may occur during the first 1-3 weeks of starting the Pill, or if you miss a pill. If the bleeding becomes heavier or lasts more than a few days or the bleeding happens after you have been on the pill for a few months, keep taking the pill and talk with your health care provider.
• Nausea: Nausea occasionally occurs when you first start taking the Pill and will often go away in a few days. It is less likely to occur if the Pill is taken after dinner or with a bedtime snack.
• Headaches: Headaches may occur because of stress at school or home, too little sleep, sinus infections, or migraines. The Pill can make headaches better or worse. If your health care provider thinks your headaches are related to the Pill, he/she may prescribe an oral contraceptive pill with a lower amount of estrogen or have you go off the Pill for a short time. If you have migraine headaches, talk to your health care provider about whether the Pill is right for you.
• Mood changes: Feeling up and down emotionally can sometimes happen to anyone and is unlikely to be caused by the Pill. Exercise and a healthy diet may help along with talking to a counselor. Make sure you let your health care provider know how you are feeling.
• Sore or enlarged breasts: Very occasionally, your breasts may become tender and/or get larger, but usually they will stay the same.
• Weight change: Some teens gain weight and some teens lose weight while on the Pill, but most stay exactly the same. Try to remember to watch your portion sizes, avoid fast food, and eat 5-7 servings of fruits and vegetables each day. Drink lots of water and don't forget to exercise! Just in case you were wondering, there are no calories in the Pill.

If side effects occur, they are usually mild and go away in the first three to four cycles. If you do have side effects, talk with your health care provider. If the side effects are uncomfortable or if they don't go away, your health care provider may switch you to a different kind of birth control pill.

Are there any serious side effects of birth control pills that I should be worried about?

Most young women who take birth control pills have few or no problems. If you do have any of the following problems, call your health care provider right away.

Remember: ACHES

• Abdominal or stomach pain (severe)
• Chest pain (severe), cough, shortness of breath
• Headache (severe), dizziness, weakness, or numbness
• Eye problems (vision loss or blurring), speech problems
• Severe leg pain (calf or thigh)

Blood clots: A blood clot in your leg or lung is a very rare but serious side effect. If you suddenly have pain or swelling in your leg, or shortness of breath and/or chest pain, see your health care provider immediately. If you have a history of blood clots, you should not take the Pill. Tell your health care provider if anyone in your family (blood relative) has ever had blood clots, especially when they were young. The Pill increases the risk of blood clots three to fourfold or 15-20 per 100,000 young women per year, which is less than with pregnancy. Blood clots are more likely to develop if you're also a smoker, overweight, having surgery, or sitting on a plane for a long time. To lessen your chances of blood clots, don't smoke, and if you're on a long plane trip, get up, walk around, and drink lots of water. If you're scheduled for surgery, and will be unable to move around much after surgery, ask your health care provider about stopping the Pill for 3-4 weeks before surgery and after the surgery until you are up and around.

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Written and reviewed by the CYWH Staff at Boston Children's Hospital

Updated: 10/18/2011

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