What is the Birth Control Shot (DMPA, Depo-Provera)?

The Birth Control Shot is a long-acting injectable birth control which contains the hormone progestin. It is given by injection and repeat injections are approximately every 3 months. It prevents pregnancy by thickening the cervical fluid to keep sperm from reaching an egg, and also may stop the release an egg (ovulation) in some users.

How effective is the Birth Control Shot?

The shot is a very effective method of birth control. The shot is about 96% effective at preventing pregnancy in typical use, which means that around 4 out of 100 people who use it as their only form of birth control will get pregnant in one year. With consistent and correct use as described in this fact sheet, it can be over 99% effective.

How can I get the birth control shot?

You can visit a clinic to get the shot or a prescription for it and talk with a healthcare provider about whether it is right for you. You will then need to visit a clinic every 11-14 weeks to get your shots. In BC, for people with MSP, the birth control shot is free. For those without MSP the cost is ~$50 for one dose.

  • Lighter or no periods (which is safe) – over time most people stop bleeding completely
  • Improved menstrual symptoms for some users (such as cramps)
  • Private/discreet (there are no signs that you are using this method)
  • You only need to remember to get the shot every 3 months
  • You have complete control over the method and no one can interfere with its effectiveness
  • May possibly treat and decrease pain associated with endometriosis
  • Reduced risk of uterine cancer and ovarian cancer
  • A good choice for people who cannot use estrogen
  • Unpredictable bleeding is common especially during the first year of use, including spotting, prolonged bleeding or no bleeding. This often improves over time.
  • You need to plan ahead to return every 11-14 weeks for injections
  • Side effects may include weight gain, headaches, breast tenderness and mood changes
  • Side effects from the shot may continue for 6 or more months after you have stopped using it
  • When you stop using the shot, there may be a delay in return to fertility (on average 9 months), but some people get pregnant right away
  • No protection against sexually transmitted infections (STIs)

When do I start the shot and when is it effective?

It is recommended you get the shot right away. The shot is effective in preventing pregnancy after one week of use, so you need to use a backup method of birth control such as condoms, or not have sex for 7 days. You do not have to wait for your period to start, but if you happen to get your shot within the first 5 days of your period you are protected right away.

What if I am late for my injection?

If it is less than 15 weeks since your last injection


  • Get your next shot as soon as possible.
  • You will still be protected from pregnancy as long as you receive the dose before the end of 15 weeks.
If it has been more than 15 weeks since your last injection


  • Get your next shot as soon as possible
  • You may not be protected from pregnancy. To reduce the chance of getting pregnant:
    • Use a backup method such as condoms, or do not have sex until 7 days after your shot.
    • Consider using emergency contraception if you had sex without a condom in the last 5-7 days. For information on emergency contraception please click here.

Seek medical attention immediately if you have any of the following symptoms, as they could indicate a serious complication:

  • Signs of pregnancy
  • Heavy bleeding
  • Depression
  • Severe, lower abdominal pain (may be a sign of pregnancy)
    Pus, prolonged pain, redness, itching or bleeding at the injection site (may be a sign of infection)

The shot may have an effect on bone density, but this is reversible. If you have concerns about your bone density talk to your health care provider.

Some medications and over-the counter herbal supplements may interact with or decrease the effectiveness of birth control. Be sure to mention that you are using birth control to your health care provider or pharmacist.

Questions? We’re here for you!

We know it can be confusing to choose and use a method. We are here to help.

You can visit one of our Options for Sexual Health Clinics to speak with a health care provider. Our Sex Sense Team is available Monday-Friday 9 a.m. to 9 p.m. by phone 1-800-739-7367 or by email at to answer your questions about birth control, or any other questions about sex, sexuality, or sexual health.

This fact sheet contains general information and should not be used in place of individual consultation with a qualified healthcare provider.

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