Go to Content Go to Navigation Go to Navigation Go to Site Search Homepage

The birth control shot (Depo-Provera) is a very effective method of birth control. It works best when you get the shot every 12 weeks.

Want the shot?

Find a Health Center

How effective is the birth control shot?

When used perfectly, the birth control shot effectiveness is more than 99%, meaning less than 1 out of every 100 people who use it will get pregnant each year. But when it comes to real life, the shot is about 96% effective, because sometimes people forget to get their shots on time. So, in reality, about 4 out of every 100 shot users will get pregnant each year.

The better you are about getting your shot on time, the better it will work. But there’s a very small chance that you could still get pregnant, even if you always get the shot on time.

If effectiveness is the most important thing to you when picking what birth control to use, you might want to check out IUDs and the implant. They’re the most effective kinds of birth control. But if you decide the shot is right for you, make sure you always get your follow-up shots on time.

What if I’m late getting my birth control shot?

If you get your shot late, you may not be protected from pregnancy — but it depends on how late you are. You can get your follow-up shots as early as 10 weeks after your last shot, or as late as 15 weeks after your last shot.  But, if you get your shot more than 15 weeks after your last shot, you’ll need to use another method of birth control, like a condom, for the first week after getting your shot.

If you have vaginal sex without using a condom more than 15 weeks after your last shot, you should use emergency contraception. You may also need to take a pregnancy test before getting your next shot.  The best way to prevent pregnancy while using the shot? Make sure you always get your shot on time, every time.

More questions from patients:

What can stop the depo shot from working?

For the depo shot to work as well as possible, you have to remember to get a new shot every 12-13 weeks. That’s about every 3 months, or 4 times a year. You can make a shot appointment at your local Planned Parenthood health center. If you have vaginal sex without using a condom more than 15 weeks after your last shot, use emergency contraception. You may also need to take a pregnancy test before getting your next shot.  

There are also some drugs and herbal products that can make the shot work less well, including: 

  • The antibiotics Rifampin, Rifampicin, and Rifamate (other antibiotics don’t make the shot less effective)

  • The antifungal Griseofulvin (other antifungals don’t make the shot less effective) 

  • Certain HIV medicines

  • Certain anti-seizure medicines (these are sometimes also used to treat psychiatric disorders like bipolar disorder)

  • The herb St. John’s Wort

  • The hypertension (high blood pressure) medicine, Bosentan

What if I'm late getting my birth control shot?

It depends on how late you are. You can get your follow-up shots as early as 10 weeks after your last shot, or as late as 15 weeks after your last birth control shot.  But, if you get your shot more than 15 weeks after your last shot, you’ll need to use backup birth control, like a condom, for the first week after getting your shot.

If you had vaginal sex without using a condom more than 15 weeks after your last shot, you can use emergency contraception to prevent pregnancy up to 120 hours (5 days) after sex. You may also need to take a pregnancy test before getting your next shot. The best way to prevent pregnancy while using the shot is to make sure that you get every shot on time.

Was this page helpful?
You’re the best! Thanks for your feedback.
Thanks for your feedback.

The Shot

  • 96% effective

  • Costs up to $150, but can be $0

  • Injected by a doctor or nurse, or yourself at home

  • Get it every 3 months

The shot doesn’t protect you from STDs. Use a condom with the shot to help stop pregnancy and STDs.
See All Methods

We and our third partners use cookies and other tools to collect, store, monitor, and analyze information about your interaction with our site to improve performance, analyze your use of our sites and assist in our marketing efforts. You may opt out of the use of these cookies and other tools at any time by visiting Cookie Settings. By clicking “Allow All Cookies” you consent to our collection and use of such data, and our Terms of Use. For more information, see our Privacy Notice.

Cookie Settings

We, and our third-party partners, use cookies, pixels, and other tracking technologies to collect, store, monitor, and process certain information about you when you access and use our services, read our emails, or otherwise engage with us. The information collected might relate to you, your preferences, or your device. We use that information to make the site work, analyze performance and traffic on our website, to provide a more personalized web experience, and assist in our marketing efforts. We also share information with our social media, advertising, and analytics partners. You can change your default settings according to your preference. You cannot opt-out of required cookies when utilizing our site; this includes necessary cookies that help our site to function (such as remembering your cookie preference settings). For more information, please see our Privacy Notice.

Marketing

On

We use online advertising to promote our mission and help constituents find our services. Marketing pixels help us measure the success of our campaigns.

User Feedback and Session Replay

On

We use qualitative data from LogRocket, UserZoom, Hotjar and AB Tasty to learn about your user experience and improve our products and services. LogRocket allows us to view session replays.