The patch releases a daily dose of hormones through the skin into the bloodstream to prevent pregnancy.
It contains the same hormones as the combined pill – oestrogen and progestogen – and works in the same way by preventing the release of an egg each month (ovulation).
It also thickens cervical mucus, which makes it more difficult for sperm to move through the cervix, and thins the womb lining so a fertilised egg is less likely to be able to implant itself.
- When used correctly, the patch is more than 99% effective at preventing pregnancy.
- Each patch lasts for 1 week. You change the patch every week for 3 weeks, then have a week off without a patch.
- You don’t need to think about it every day, and it’s still effective if you’re sick (vomit) or have diarrhoea.
- You can wear it in the bath, when swimming and while playing sports.
- If you have heavy or painful periods, the patch can help.
- The patch can raise your blood pressure, and some women get temporary side effects, such as headaches.
- Rarely, some women develop a blood clot when using the patch.
- The patch may protect against ovarian, womb and bowel cancer.
- It may not be suitable for women who smoke and who are 35 or over, or who weigh 90kg (14 stone) or more.
- The patch does not protect against sexually transmitted infections (STIs), so you may need to use condoms as well.