What are birth control pills?
Birth control pills (oral contraceptives) are a method of
birth control that uses hormones to prevent pregnancy.
The man-made female hormones in the pills change a
woman's natural hormone levels and prevent her ovaries
from releasing an egg each month. The hormones also help
prevent pregnancy in 2 other ways. They cause a
thickening of the mucus on the cervix and they change the
lining of the uterus. The thickened mucus on the cervix
makes it hard for sperm to enter the uterus. The change
in the lining of the uterus helps prevent a fertilized
egg from attaching to the uterus.
The most commonly used pills are "combined" pills. They
contain man-made forms of 2 hormones: estrogen and
progesterone. There is also a progesterone-only pill (the
mini-pill), but it is not as effective and causes a lot of
blood spotting between menstrual periods.
How are the pills used?
The combined pills usually come in a package of 28 pills.
They are also available in 21-pill or 91-pill packs. You
and your healthcare provider will decide which type of
package is best for you. Your provider will probably advise
you to start taking the pills on the Sunday after your
period has started or on the first day of your next period,
depending on your preference.
- Try to take your pill at the same time every day. This
will help you remember to take the pills. It will also
help keep hormone levels steady.
- Use a backup method of birth control (such as condoms and
spermicide) until you have been taking the pills for 2
weeks.
- Use condoms, even though you are taking birth control
pills, for protection against sexually transmitted
disease unless you have a long-term, single-partner
relationship.
- If you have bleeding between periods for several cycles
you may need a different pill. Call your healthcare
provider for an appointment.
- Any time you are seen for medical reasons, be sure to
mention that you are taking birth control pills. This is
particularly important if you are admitted to the
hospital or having surgery.
21-day pill pack
If you are using the 21-pill pack, take 1 pill every day for
3 weeks. Stop taking the pills for 7 days and then start a
new pack. Your period comes during the week that you are
not taking pills.
28-day pill pack
If you are using the 28-day package, take 1 pill every day
for 4 weeks and then start a new package the next day. The
last 7 pills are inactive and contain no medicine for birth
control. They just keep you in the habit of taking a pill
every day. Your period comes during the week that you are
taking the last 7 pills.
91-day pill pack
If you are using the 91-day pill pack, you take 1 pill of
active medicine every day for 12 weeks (84 days). Then
you take 1 inactive pill every day for 1 week (7 days).
You will have your period while you are taking the
inactive pills. This means that you have a period just
once every 3 months.
Generally, most women have no trouble getting pregnant after
they stop taking the pills. When you want to get pregnant,
it is recommended that you wait until you have had at least
2 normal menstrual periods after stopping the pills.
What if I forget to take a pill?
Your risk of pregnancy increases when you miss any pills.
If you forget 1 pill, take it as soon as you remember, even
if it is the next day. Take the next pill on time.
If you miss 2 or more doses in a row, see the information
sheet that comes in the medicine package or ask your
healthcare provider what to do. Use an additional method of
birth control, such as condoms or spermicide, until your
next period starts.
When can I start taking birth control pills after having a
baby?
If you are breast-feeding your baby, do not use birth
control pills unless your healthcare provider says it is
OK. Remember that breast-feeding is not sure protection
against pregnancy, so use another form of birth control
before you start taking birth control pills again.
If you are not breast-feeding your baby, you may be able to
start taking birth control pills 1 to 2 weeks after the
birth or when you begin menstruating again. Use condoms or
spermicides until you start the pills. Be sure to check
with your healthcare provider before you start taking birth
control pills again.
What are the benefits?
The benefits are:
- Birth control pills are 92 to over 99% effective in
preventing pregnancy. This means that, for every 100
women who use the pills for a year, 8 or fewer women
will become pregnant by the end of the year.
- You do not have to interrupt lovemaking to use a birth
control device or spermicide.
- Periods become regular and usually lighter. Menstrual
cramps may be less severe.
- Long-term use lowers the risk of cancer of the ovary.
- Birth control pills may reduce symptoms of
premenstrual syndrome (PMS).
What are the disadvantages?
One disadvantage of birth control pills is that you must
remember to take a pill every day.
The pills usually have no side effects, but sometimes they
cause side effects such as:
- irregular menstrual bleeding or spotting for the first
few months after you start birth control pills
- dizziness
- nausea and vomiting
- swelling of your hands or ankles
- pain, swelling, or tenderness in the abdomen
- breast swelling or tenderness
- more appetite and weight gain
- trouble sleeping, weakness, lack of energy, fatigue, or
depression
- headaches
- vaginal infection (usually yeast)
- allergic reaction, rash, itching
- amenorrhea (absence of menstrual period)
- less interest in sex
- changes in hair growth patterns
- vision or contact lens problems
- yellowing of the skin or whites of the eyes (jaundice).
You should not smoke. Smoking increases the risk of
serious side effects, such as heart attack, stroke, and
blood clots. This is especially true if you are over 35
years old and smoke 15 or more cigarettes a day.
Birth control pills do not protect you from sexually
transmitted diseases such as AIDS. Latex or polyurethane
condoms are the only safe way to protect against AIDS.
Some medicines can affect the way birth control pills work
in your body. Birth control pills may not keep protecting
you against pregnancy if you are taking certain antibiotics
or medicines for seizures or fungal infections. Tell your
healthcare provider about all medicines or natural remedies
you are taking. You may need to use an additional form of
birth control while you are taking these medicines.
Who should not take birth control pills?
Some women with chronic diseases or other problems should
not use birth control pills. For example, women who
have had blood clots, certain cancers, heart attack. or
stroke should not use the pills. Your healthcare provider
will discuss your medical history with you.
When should I call my healthcare provider?
Call your provider right away if you have:
- sharp chest pain or sudden shortness of breath or are
coughing up blood
- sudden severe headache or vomiting, dizziness or
fainting, or problems with vision or speech
- sudden partial or complete loss of vision
- yellowing of the skin or whites of the eyes (jaundice),
especially with fever, tiredness, loss of appetite, dark
urine, or light-colored bowel movements
- unexplained pain, weakness, or numbness in the calf of
one of your legs
- severe pain, swelling, or tenderness in the abdomen.
Call during office hours if you have:
- problems with your menstrual periods, such as bleeding
between periods, prolonged periods, or missed periods, or
you think you are pregnant
- more headaches than you used to have
- severe mood changes
- vaginal discharge with itching.
Developed by David W. Kaplan, MD, and McKesson Corporation
This content is reviewed periodically and is subject to
change as new health information becomes available. The
information is intended to inform and educate and is not a
replacement for medical evaluation, advice, diagnosis or
treatment by a healthcare professional.
Copyright © 2007 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.