What is it?

A hormonal method of contraception that works in the same way as the progestogen-only pill by thickening the mucus around the cervix, but which also prevents ovulation. There are two brands available in the UK, but each provides pregnancy protection with a single jab. The contraceptive effects of the Depo-Provera injection last for three months, while a Noristerat jab lasts for two months. Both methods are over 99% effective.

How is it taken?

The injection should be carried out by your GP (doctor) and it is usually injected into the bottom or upper arm. You can have one at any time - if taken in the first five days of menstruation it is effective immediately, and if taken on another day of your cycle you will be protected after seven days.

Benefits

• Safe, effective, and a useful alternative for women who routinely forget to take the combined pill or progestogen-only pill;
• Fuss-free sex;
• Not affected by vomiting or diarrhoea
• Can be used by breastfeeding mothers;
• May help ease pre-menstrual symptoms or period pains;

Drawbacks

• Protects against pregnancy, but not sex infection. Always use a condom for maximum risk reduction;
• Disruption to menstrual bleeding. This can mean longer periods or none at all;
• Small risk of headaches, moodswings, acne and weight gain. If anything like this does kick in, it may last until the contraceptive effects wear off (i.e. two to three months).
• Fertility can take up to a year to return after use.

Not suitable for

• Women who are pregnant;
• Women with breast cancer or undiagnosed breast lump;
• Women with liver disease.

Updated: 23/04/2010