The jab releases a tiny amount of the hormone progestogen which works in two ways. Firstly it creates a sticky mucus inside your uterus making it difficult for the sperm to swim and get to the egg. The mucus acts like a barrier to stop sperm from swimming through the opening of your uterus. If sperm can’t reach the egg, then you can’t get pregnant.
It also stops you from ovulating, so an egg doesn’t leave your ovaries once a month. When there is no egg in the tube, there is nothing for the sperm to meet. So if a sperm does happen to get through the mucus barrier there will be nothing for it to fertilise. No egg, no pregnancy.
Getting the jab is simple. You get an injection in your upper arm or butt cheek, and as easy as that it’s done. You need to have the jab every three months to maintain its effectiveness.
You will feel a little pinch and sting as the injection goes in. It’s just like getting a vaccination. Your upper arm or butt cheek may be a little tender for the rest of the day, so take it easy.
You can have sex as soon as you feel ready after you get the jab. But depending on where you are in your cycle you may need to use contraception for a little longer.
If you get the jab within the first 5 days of your period, you are protected straight away.
If you get the jab at any other time during your cycle, you are not protected for the first 7 days. Using another form of contraception for the first week will help prevent pregnancy.
The jab is an amazing form of contraception, but it doesn’t protect you from STIs. Condoms are the only way to protect yourself from STIs.
The jab works really well if you get it on time every 12 weeks. If you get your next jab within the 12-week window, you won’t need to use contraception in between jabs. If you are a little late at getting your jab, you will just need to use another form of contraception up until the first week after your next jab.
You can get your next jab as early as 10 weeks after your last.
We will text you on week 10 to remind you to book in for your next shot.