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 women'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
  • Most women (7 in 10) have no periods
  • Often suitable for people who can't take oestrogen
  • It’s extremely good at preventing pregnancy
  • It protects against cancer of the womb


  • It’s an injection, which some people hate
  • May cause irregular bleeding
  • Weight gain is fairly likely (3kg in 2 years)
  • 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

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 women can continue to have the injection from teenage until they’re 50

Women don’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 women 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 women 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 women gets 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

The injection is the best choice for stopping periods temporarily

Many women 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 women 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 women remember when to schedule their next injection  

For women 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 women can have it

What's right for you?

Good to know

Some women 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. Most women on the injection will have no periods (about 7 in 10), and for those who do have periods, they are usually much lighter and less painful. Irregular bleeding can happen when first stating the injjection, 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 women 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.

How much effort is the injection?

Women get the injection every three months from their GP, nurse, sexual health clinic or family planning clinic. 

For further information about where to get the injection, click here

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 women 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 97% effective – meaning that out of 100 women taking the pill for a year, about 3 will have an unplanned pregnancy.

How does it work?

The injection temporarily stops a woman’s 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.

What's right for you?