Depo Provera or The Shot

photo of depo provera infection

The birth control shot or injection (also called “Depo Provera”) is a hormone (progesterone only) injection that is given every 12 weeks into the upper arm or buttock of the female user by a doctor or nurse.


  • Reliable (99.7% if injected every 12 weeks)
  • Easy to maintain because user only needs to return for injection every 12 weeks.
  • Private and discreet – the injection is given in a private office
  • Suitable for users who cannot use estrogen for medical reasons.


  • It does not protect against STIs.
  • Irregular bleeding is common during the first few injections.
    Some users find this inconvenient.
  • If a user does not like the method, it has to wear off as it can’t be taken out of the bloodstream.
  • It’s given by injection so people with needle issues can’t use it.
  • It can decrease bone density during use Because of this, Depo is usually not used by women who have existing issues with bone density. Recent research has shown that bone density loss is reversed once users discontinue use
  • Delayed fertility. It can take up to a year and a half to become fertile again after you stop using Depo Provera. Women who are planning to get pregnant within one to two years should use other methods of birth control.

How effective is the shot?

The shot is 99.7% effective against pregnancy if used correctly which means it is given into arm or buttock every 12 weeks. It does not protect against STIs. Condoms should be used as well to provide STI protection and increase pregnancy protection.

How do I get the shot (depo provera)?

The shot (depo-provera) is only available by prescription from a doctor or a nurse. The shot varies in cost depending on where you have your prescription filled. You don’t need a pelvic exam to get a prescription for the shot.

How does the shot work?

The shot contains the hormone progestin to prevent pregnancy.

The shot:

  • prevents the ovaries from releasing an egg each month (ovulation).
  • thickens the cervical mucus, which makes it difficult for sperm to travel through the cervix to uterus.
  • thins the lining of the uterus which makes it difficult for a fertilized egg to implant itself into the wall of the uterus.
  • The shot is 99.7% effective if given every 12 weeks.

How do I use the shot correctly?

  • Your first shot should be given within the first five days of your period. Use a back-up method such as condoms for the first week after the first injection.
  • Return to a clinic for injection every 12 weeks. Set the alarm on your phone calendar or download a birth control reminder app to keep you on track. They’re free and easy to use.
  • A back-up method is not necessary with subsequent injections if they are given on time.

What if I miss the date for my next shot?

If you have unprotected sex after missing the date for your injection, contact the clinic at (250) 592-3479 to discuss taking the “Emergency Contraceptive Pill (ECP)”. You can also get Emergency Contraception from pharmacies in BC without a prescription. The sooner you take the ECP the more effective it is at preventing pregnancy.

Does Depo have any other possible side effects?

Irregular bleeding is common Most women will have irregular menstrual bleeding after they get the injection. Some women have spotting on and off, some bleed frequently, and some may not bleed at all (this is not harmful). Usually the amount of bleeding decreases with time, but bleeding will always be unpredictable. Remember this is NORMAL for this medication. 55% percent of women will have no periods after one year of use; 70-80% will have no periods after two years of use. Irregular bleeding is common for 6-8 months after stopping this method.

Weight gain of an average of 5-10 lbs. Good eating habits and regular physical activity should be sufficient to deal with any weight gain that may occur.