What is it?

It is an injection of medroxyprogesterone acetate, a progestin medication. There is no estrogen in this hormone injection. It is 99.7% effective when used perfectly every 12 weeks to prevent pregnancy. A health care professional (e.g. RN or MD) must give it to you as a shot in the buttocks or in the upper arm.

How does it work?

The hormone enters the bloodstream slowly over 12 weeks and suppresses ovulation in most women, so that no egg is released from the ovaries. It also helps to thicken the cervical mucus making it harder for sperm to travel into the uterus. It induces a thinner lining of the uterus which is not suitable for implantation.

How do I start using it?

You should start the depo-provera when on your period, or just after an abortion. You get a prescription from a physician, fill it at the pharmacy, and come to the clinic for injection. At that time, you will be told when you need to come back for the next injection, in 12 weeks time.

When does it start working?

If you start on the last day of your period, or on the day after an abortion, it will start working right away. If you are absolutely positive you have not had sex since your period, it can be given between your periods, but do not rely on it for 7 days. Use condoms or refrain from sex.

Can I miss my period when on it?

Yes, you can. After a year (4 injections) 50% of women have no bleeding. Many women like this aspect of the medication.

Is it safer than the pill, ring or patch? 

Yes, for women who cannot take estrogen, this is a good alternative. There are fewer health risks than there are with the combined oral contraceptive, the ring or the patch.

What if I forget the next injection?

That’s a concern. Take the morning after pill, or a copper IUD, and get the injection done right away. Take a pregnancy test within 2-3 weeks if you have had sex.

What are danger signs that something is wrong?

If you use depo-provera for over 2 years, some women have reduced bone density measurements. This is reversible, as it is with breast feeding. However if you are at more risk for osteoporosis (e.g. on steroids, eating disorder, athlete with no menses), you may be more at risk for a fracture when on depo-provera. You should take adequate daily calcium, continue or increase your weight bearing exercises, and stop smoking.

Many women really like the injection for the following reasons;

  • You don’t have to remember a pill each day,

  • Many women stop having a period

  • It usually reduces cramping when bleeding

  • It is private, no one can find a pill packet, or evidence

  • It is not affected by other medication you may be on

  • It can be used if you are over 35 and smoke

  • It is 97-99.7% effective (depends on your perfect use)

  • It allows for more spontaneous sex as you are protected

There are some health benefits to having the injection;

  • It can reduce endometriosis symptoms

  • It is believed to reduce endometrial cancer

  • It is reversible- once you stop, you can get pregnant

  • It will help you avoid pregnancy till you are ready

Successfully switching from another method:

  • If you are now on the birth control pill, you can start the injection any time, or at the end of the 21 days.

  • If you are using the Ring or the Patch, have the injection on the last day of use, before the period starts.

  • The first dose is adjustment and may lead to irregular bleeding. Most women are happier by the 2nd or 3rd dose.

Some women don’t like the depo provera injection for the following reasons;

  • It is likely to cause spotting or irregular bleeding, especially for the first 1-2 doses. It usually resolves

  • It may cause hormonal side effects like acne, bloating, nausea or mood changes including low sex drive

  • Some women have associated weight gain

  • You have to see a health professional for the injection

  • It doesn’t protect against STIs

Some women SHOULD NOT use the injection;

  • Women who want to get pregnant soon. It can take an average of 9 months to start ovulating again

  • Women who are on steroids, who have an eating disorder, or athletes with very low body weight. You may be at increased risk of osteoporosis.

  • Women who have undiagnosed vaginal bleeding

  • Women with breast cancer

  • Women who have serious liver problems

  • Women who have multiple risks for heart disease/stroke

  • Women who are breastfeeding (first 6 weeks only)