[See also: Using the pill; not for contraception]

How does the pill work?

Without birth control pills, estrogen and progesterone are released from your ovaries. When you are on birth control pills (“the pill”), your body knows that estrogen and progesterone are coming from somewhere else (from the pills). Because your ovaries don’t need to release hormones, they “take a little nap.” While the ovaries are “napping,” they don’t release hormones, and don’t release an egg, which is how they work for birth control.

Forgetting pills or taking them at different times of the day can cause the ovaries to “wake up.” When that happens, the ovaries release hormones, which can cause irregular periods and may release an egg, which can cause women to get pregnant.

How to use the pill

  • Start your first pack of pills as directed - You may be told to start on the first day of your next period, or - on the Sunday after your next period begins, or - on the day you are in the clinic or office.
  • After starting the pill, continue taking one pill every day at the same time. There should not be any days that you don’t take a pill.
  • With birth control pills the first 21-24 days are hormone pills and the last 4-7 are usually sugar pills (placebo). Most people start their bleeding on the 2nd or 3rd day of the placebo pills.
  • If you are taking the pills with an extended cycle, your doctor or nurse practitioner will tell you when to expect bleeding.

What to do if you forget to take a pill

  • If you forget to take a hormone pill at your usual time, take your pill as soon as you remember. Then take the next pill at the usual time. You will be taking two pills that day.
  • If you forget to take a hormone pill for 1 whole day, take 2 hormone pills the next day at the regular time.
  • If you forget to take a hormone pill for 2 days, take 2 hormone pills for each of the next 2 days.
  • If you forget to take the pill for 3 days, your ovaries may “wake back up.” Start a new pack of pills.
  • Forgotten placebo pills do not need to be made up.
  • If you have questions about what to do with missed or late pills, call the clinic.

Are there side effects with birth control pills?

Most people don’t have any side effects with birth control pills. However, during the first 3 months you may experience:

  • Bleeding or spotting during the hormone pills. This is called breakthrough bleeding and usually happens more during month 1, less during month 2, and by month 3 most people have regular periods during the last week of pills. If breakthrough bleeding continues after month 3, you may need a different pill.
  • While other side effects are not common, you may have nausea, breast tenderness, headaches, or mood changes. If this happens, it is usually mild and doesn't last long.
  • If you are having side effects that are making you feel miserable, call the clinic. Do not stop taking your pills.
  • Birth control pills do not cause weight gain.

Danger signs on the pill

Call the office immediately if you have:

  • Dizziness
  • Vision changes

Consider immediate evaluation if you experience the following:

  • Severe headaches (the worst headache you’ve ever had)
  • Chest pain
  • Pain in the calf of one leg


  • Birth control pills do not protect against sexually transmitted infections. Use condoms every time you have sex.
  • Never run out of pills. You can always call your pharmacy and ask for a refill.
  • Never take someone else’s birth control pills or share your pills with anyone else.
  • If you are having a problem, don’t just stop taking the pill. Call the clinic.
  • There are about 100 different birth control pills. If you feel miserable while taking the pill you were given, call the clinic and ask to change to another pill that may be better for you.