The injection (or depo) is given as an injection into the bottom or thigh every three months.
It contains a hormone called progestogen which is very similar to the body's own hormones.
Long-lasting and convenient, it can stop periods temporarily.
- It doesn’t interrupt sex
- It helps to make periods lighter
- It helps to make periods less painful
- It can stop periods (4 in 10)
- Often suitable for people who can't take oestrogen
- It’s extremely good at preventing pregnancy
- It can help manage some of the symptoms of Endometriosis
- It may protect against cancer of the womb and ovaries
- It’s an injection, which some people hate
- May cause irregular bleeding
- Weight gain may happen
- Possible changes in mood and sex drive
- Not suitable for someone who definitely wants a regular period
- It can take several months to wear off
- No protection against STIs
- It can temporarily decrease bone density during use
You don’t need a break from the injection
It should be reviewed every two years to check whether it’s still the best choice of contraception, but you can continue to have the injection from your teenage years until you're 50
The body doesn't need a period once a month
The injection prevents the lining of the womb from building up – blood doesn’t build up inside, and it can help people feel more energetic if they are not losing iron each month in a period. It can also be convenient to not have periods. Find out more about periods here
The injection does not cause infertility
When you come off the injection, fertility returns to normal in an average of 6 months, although it can be sooner or later than this. It’s important to know that it’s less easy to get pregnant as you get older – it’s naturally harder to get pregnant over the age of 35 (although this can definitely still happen). Find out more about infertility here
Many find the injection good for controlling period pain, having a break from periods, and to level out the moodiness of premenstrual tension
The injection is great for people who forget to take pills
Because the injection is only every few months, it means they don’t have to rely on taking a pill every day. Apps and text reminder services are available to help people remember when to schedule their next injection
If you are planning to have a baby soon, the injection is not the best choice
Clinic visits are needed to check general health and family history. Some health problems mean that the injection won’t be right for you, but most can have it
Good to know
Some people love the injection, and others don't get on with it.
Periods can stop on the injection because it’s very good at keeping the lining of the womb thin. Around 4 in 10 people using the injection will have no periods, and for those who do have periods, they are usually much lighter and less painful. Irregular bleeding can happen when first starting the injection, but is likely to settle down with each injection.
Once you stop using the injection, it can take an average of 6 months for fertility to return to normal, but some get pregnant soon after coming off it. Sometimes it takes longer than 6 months to get periods back, so other methods are better if you plan to get pregnant soon.
Weight gain can happen on the injection. This is more likely if you are under 18 or already overweight (BMI>30)
How much effort is the injection?
The injection is given every three months by a GP, nurse, sexual health clinic or family planning clinic.
How effective is the injection?
The injection is very effective. If the injections are given on time (every three months), it is more than 99% effective – meaning that if 100 people used the injection for a year, less than one will have an unplanned pregnancy. However, allowing for the ups and downs of life, the average user can expect it to be around 94% effective – meaning that out of 100 people using the injection for a year, about 6 will have an unplanned pregnancy.
How does it work?
The injection temporarily stops the body from releasing an egg each month. It also thickens the fluid around the neck of the womb (which stops sperm getting to an egg), and makes the lining of the womb thinner so that a fertilised egg can’t settle.
Does the injection affect my risk of getting cancer?
Studies have shown a small increased risk of breast cancer in people who use hormonal contraception compared to people that don't. This increased risk disappears 10 years after you stop using the injection.