Depo-Provera

The birth control shot is an injection of a hormone that prevents pregnancy. Each shot prevents pregnancy for three months.

The shot is also known by the brand name Depo-Provera, or by the name of the medicine in the shot, DMPA.

Like other methods of birth control, the birth control shot releases a hormone — progestin — into the body. Hormones are chemicals made in our bodies. They control how different parts of our bodies work.

The progestin in the shot works by

• Keeping eggs from leaving the ovaries. Pregnancy cannot happen if there is no egg to join the sperm.
• Making cervical mucus thicker. This keeps sperm from getting to the eggs.

Effectiveness is an important and common concern when choosing a birth control method. The birth control shot is one of the most effective methods of birth control available. It works best when you get the birth control shot regularly, every 12 weeks.

• Less than 1 out of 100 women will get pregnant each year if they always use the birth control shot as directed.
• About 6 out of 100 women will get pregnant each year if they don’t always use the birth control shot as directed.

Keep in mind the birth control shot doesn’t protect against sexually transmitted infections. Use a latex or female condom to reduce the risk of infection.

If you get the birth control shot within the first seven days after the start of your period, you are protected from pregnancy immediately. If you get the shot within five days after miscarriage or an abortion, or within three weeks after giving birth, you are protected from pregnancy immediately. Otherwise, you need to use some form of backup birth control — like a condom, female condom, diaphragm, sponge, or emergency contraception (morning after pill) — for the first week after getting the shot.

Each shot of Depo-Provera will protect you from pregnancy for 12 weeks. So you will need to go to your health care provider every 12 weeks for a shot. If you are two or more weeks late getting your shot, your health care provider may ask you to take a pregnancy test, or may advise you to use emergency contraception if you had vaginal intercourse in the previous 120 hours (five days).

Most women can use the birth control shot safely. But all medications have some risks, so safety is a concern when choosing a birth control method. Certain conditions increase the risk of serious side effects.

You should not use the shot if you

• are taking the medication aminoglutethamide to treat Cushing’s syndrome
• are pregnant
• have breast cancer
• have had fragility bone fractures (breaks)

Talk with your health care provider about your health and whether the shot is likely to be safe for you.

There are many other methods of birth control that may be safe for you if you cannot use the shot. Read about other methods to find one that may be right for you.

• Using the birth control shot is safe, simple, and convenient.
• The shot provides very effective, long-lasting pregnancy protection.
• There is no daily pill to remember.
• There is nothing to do right before having sex.
• Some women say it improves their sex lives because it helps them feel more spontaneous.
• It is also a very private method of birth control — there is no packaging or other evidence that might be embarrassing for some people.
• The birth control shot does not contain estrogen, another type of hormone that is in many types of birth control, including the pill, patch, and ring. This means the shot can be a good choice for women who cannot take estrogen and for women who are breastfeeding.
• The shot can help prevent cancer of the lining of the uterus.

Some women may have undesirable side effects while using the birth control shot. But many women adjust to it with few or no problems. Serious problems do not occur often.

Irregular bleeding is the most common side effect, especially in the first 6 to 12 months of use.

• For most women, periods become fewer and lighter. After one year, half of the women who use the birth control shot will stop having periods completely.
• Some women have longer, heavier periods.
• Some women have increased spotting and light bleeding between periods.

These side effects are completely normal. Some woman may worry that they are pregnant if they do not have a regular period. But when the birth control shot is used correctly, it is very effective. If you are concerned about a possible pregnancy, you can always take a pregnancy test.

There are also some less common side effects:

• change in sex drive
• change in appetite or weight gain
• depression
• hair loss or increased hair on the face or body
• headache
• nausea
• sore breasts

There is no way to stop the side effects of Depo-Provera — they may continue until the shot wears off, in 12 to 14 weeks.

It’s important that you find a method that won’t make you feel sick or uncomfortable. If the side effects from the birth control shot continue to bother you, talk with your health care provider.

Because the birth control shot is long lasting, it can take a long time to get pregnant after getting your last shot — anywhere from 6–10 months. So, Depo-Provera is not a good birth control method for you if you’re thinking of getting pregnant soon.
Serious problems usually have warning signs.

Report any of these signs to your health care provider immediately:

• a new lump in your breast
• major depression
• migraine with aura — seeing bright, flashing zigzags, usually before a very bad headache
• pus, pain for many days, or bleeding where you were given the shot
• unusually heavy or prolonged vaginal bleeding
• yellowing of the skin or eyes

Although Depo-Provera is highly effective in preventing pregnancy, in the very rare cases where pregnancy does occur, it is more likely to be an ectopic pregnancy, which can be life threatening.

Women who use the birth control shot may have temporary bone thinning. It increases the longer they use it. Bone growth begins again when women stop using the shot. Talk with your health care provider about the risks. You can help protect your bones by exercising regularly and getting extra calcium and vitamin D, either through the food you eat or from vitamin supplements.