Birth Control Pills: General Information

Key Facts
  • There are many different kinds of birth control pills (BCPs).
  • Most types of birth control pills contain two hormones: estrogen and progestin (which is similar to progesterone). These are called combined birth control pills.
  • Birth control pills are also called “oral contraceptive pills” (OCPs), “hormone pills,” or “the Pill.”
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  • Young men's version of this guide

birth control pills

Birth control pills (also called oral contraceptive pills and the “Pill”) are a type of female hormonal birth control method and are very effective at preventing pregnancy. The Pills are small tablets that you swallow each day. Most pills contain two types of synthetic (artificial) female hormones: estrogen and progestin. These are similar to the estrogen and progesterone normally made by the ovaries. These pills are called “combination oral contraceptives,” and there are many different kinds.

The hormones in the pills prevent pregnancy by suppressing the pituitary gland, which stops the development and release of the egg in the ovary (ovulation) (see female reproductive anatomy image below). The progestin also helps to prevent the sperm from reaching the egg and thins the lining of the uterus.

Another type of pill contains only one hormone (progestin) and is called either the “progestin-only pill,” or the “mini-Pill.” It works to thin the lining of the uterus and helps prevent the male’s sperm from reaching the egg.

Which birth control pill should I take?

First, talk with your health care provider to see if birth control pills are right for you. If they are, discuss which pill and what dosage is best for you.

The combined pill with both estrogen and progestin may be slightly more effective than the progestin-only pill. However, some people can’t take or tolerate estrogen, so it’s better for them to take the progestin-only pill.

How effective is the Pill at preventing pregnancy?

The Pill is very effective if you take it exactly as you are supposed to – one pill a day, taken at the same time each day. You should also use back-up contraception such as condoms if you have diarrhea or vomiting, or are taking a medication that could change the effectiveness of the birth control pill. Using condoms is always important to decrease your chances of getting a sexually transmitted infection (STI).

Out of 100 women using Combination or Progestin Only BCP’s
Typical Use: 9 People Become Pregnant icon representing 1 pregnant womanicon representing 1 pregnant womanicon representing 1 pregnant womanicon representing 1 pregnant womanicon representing 1 pregnant womanicon representing 1 pregnant womanicon representing 1 pregnant womanicon representing 1 pregnant womanicon representing 1 pregnant woman
Perfect Use: 1 or Less People Become Pregnant icon representing 1 pregnant woman
Female reproductive anatomy
Female reproductive anatomy

If you take the Pill at the same time every day (perfect use), it’s more than 99% effective. This means that if 100 people take the combination pill every day, less than 1 person will become pregnant in a year.

Although it’s obvious that the Pill is most effective against pregnancy when it’s taken at the same time every day, perfect use can be difficult for both teens and adults. That’s why it’s often considered 91% effective. This means that if 100 teens use the Pill, but don’t take it perfectly, 9 or more teens will become pregnant in a year.

What are the possible side effects of birth control pills?

The majority of teens have no side effects when taking the oral contraceptive pill. However, it’s possible to have irregular periods, nausea, headaches, or weight change especially during the first few months. Each type of oral contraceptive pill can affect each person 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 several 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, they 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 your breasts will stay the same. Breast tenderness usually goes away after a few months. If you still have problems, talk to your health care provider and see if you need to be on a pill with less estrogen.
  • Weight change: Some teens gain weight and some teens lose weight while on the Pill, but most stay the same. Try to remember to watch your portion sizes, avoid fast food, and eat 5-13 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’re usually mild and go away in the first three to four months of taking the birth control pill. 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 or a different method.

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

Most teens 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 and/or shortness of breath and/or chest pain, see your health care provider right away or go to the emergency room. 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 relative risk of blood clots by three to fourfold, but the risk of blood clots is still far 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 do smoke, it is important that your doctor knows about your smoking before you start the pill. If you’re scheduled for surgery, and won’t be able to move around much after surgery, your healthcare provider may recommend you to stop the Pill for 3-4 weeks before surgery and after the surgery until you are walking around normally.

Health Benefits

Teens are frequently prescribed birth control pills just for the medical benefits. BCPs are a safe and effective treatment for many types of medical problems, including PCOS, irregular menstrual periods, menstrual crampsacnePMS, and endometriosis.

Are there any medical benefits with taking birth control pills?

Birth control pills not only prevent pregnancy, but they also have medical benefits. Many teens take the birth control pill just for its medical benefits and not for its protection against pregnancy.

  • Regular and lighter periods: Oral contraceptive pills can help to regulate the menstrual cycle so your period comes about every 28 days. The Pill usually causes lighter periods too. You may only have a brown smudge on a tampon, pad, panty shield or underwear. The hormone doses in BCPs are very low. When you are taking the birth control pill, the lining of your uterus doesn’t become very thick so very little blood needs to come out each month. For the extended cycle pills, you might have a period every 3 months or even less.
  • Clearer skin: Birth control pills can improve acne. The hormones in most types of BCPs can help stop certain acne from forming. Be patient though, as it can take a few months to see an improvement.
  • Fewer cramps, or no cramps: Birth control pills can help to decrease menstrual cramps.
  • Other medical benefits: Because there’s less menstrual bleeding with the use of birth control pills, teens taking the pill are less likely to become anemic (have too few red blood cells). Birth control pills also lessen your chance of getting endometrial (lining of the uterus) cancer, ovarian cancer, and ovarian cysts. BCPs also protect against pregnancies that occur outside the uterus (tubal or ectopic pregnancies).

Can anybody take birth control pills?

Almost all teens can take birth control pills. There are only a few reasons why your health care provider might feel that you need to choose other methods of birth control. These reasons are called “contraindications.”

Contraindications for taking combined birth control pills include:

  • You have a genetic condition(s) that increases your risk of blood clots or a history of blood clots.
  • Migraine headaches with aura (spots and wavy flashing lights or trouble seeing that occur 5 to 30 minutes before the headache starts), or neurological symptoms (numbness, loss of speech)
  • Certain kinds of heart disease
  • High blood pressure that is not controlled with medication
  • Surgery or any other condition that prevents you from moving or getting up and walking (immobilized)