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revised Friday October 12 2007

Birth Control Pill

What is it?

The BCP contains the hormones estrogen and progesterone and prevents pregnancy by stopping ovulation (release of an egg by the ovary). It is between 97 and 99% effective if taken exactly as prescribed. The pill must be taken at the same time every day.

There are 21 and 28 day pill packs.

  • 21 day pill packs contain 21 hormone pills. Take one pill every day for 21 days. Then take no pills for 7 days. (Your period will start during these pill-free days). Then start a new pack of pills whether bleeding has stopped or not.
  • 28 day pill packs contain 21 hormone pills and 7 "fake" pills. Take one pill every day for 28 days. Then start a new pack of pills whether bleeding has stopped or not. (Your period will start during the last 7 "fake" pills.)

When should back-up methods be used with the pill?

As there is a chance of getting pregnant anytime when you don't take 7 hormone pills in a row, you need to use a back-up method of birth control such as condoms or abstain from sex (no sex). These times include:

  1. When starting your very first pack of pills.
    • Pills become effective after you have taken the first 7 pills as directed.
  2. If any pills are missed:
    • See back of sheet for instructions on missed pills.
  3. If taking prescribed or over-the-counter medications, or some street drugs:
    • Continue to take the pill as usual.
    • Abstain from intercourse or use a back-up method while taking your other medications and for 7 days after you have completed it.
    • If you are taking other medications into the 3rd week (day 15-21 of your pack), see "Missed Pills in 3rd Week" on the other side of this sheet.
  4. If vomiting occurs within 1 hour of taking a pill:
    • Take another pill from a separate pack as soon as you feel better.
    • If you have severe diarrhea or vomiting for more than 24 hours, keep taking your pills as usual if you can.
    • Abstain from intercourse or use back-up methods while you are ill and for 7 days after you feel better.
    • If you are vomiting in the 3rd week (day 15-21) of your pack, see "Missed Pills in 3rd Week" on the other side of this sheet.

If you have made any mistakes taking your birth control pills, you may be able to take the Emergency Contraceptive Pill (Morning After Pill) to help prevent pregnancy.

Remember: Use condoms every time to help prevent the spread of sexually transmitted infections (STI), HIV, and Hepatitis B.

Possible side effects of the pill:

  • bleeding between periods (break-through bleeding)
  • stomach upset or nausea
  • weight gain/bloating due to water retention
  • headaches
  • sore breasts
  • mood swings
  • lighter and/or shorter periods, or missed period
  • getting drunk faster and staying drunk longer if you use alcohol (wine, beer, liquor)
  • a decrease in some vitamin levels, so eat a well balanced diet and consider taking a multivitamin

If you take birth control pills, it is advised that you not smoke. Women who take the pill and smoke have a slightly higher chance of developing a blood clot; however, it is extremely rare.

Signs of a blood clot include:

  • severe leg pain in calf or thigh
  • severe chest pain, cough, shortness of breath
  • severe headache, dizziness, weakness and numbness
  • eye problems such as vision loss or blurring
  • speech changes such as slurring
  • severe abdominal pain

If you have any of these signs, go to a hospital right away.

For more information, call 905-799-7700 and ask for Sexual Health Information.

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Revised: Friday October 12 2007

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