What is it?
A tablet containing the hormones oestrogen and progestogen that you take daily for 21 days. After 21 days, you have seven days of break where you do not take the pills, then you start the 21 days cycle again.
How does it work?
The hormones prevent you from ovulating (releasing an egg). They also make it difficult for sperm to reach an egg, or for an egg to implant itself in the lining of your womb.
How effective is it?
If used correctly it is over 99% effective. This means that less than one woman in 100 will get pregnant in a year. If it's not taken according to instructions, then the chance of getting pregnant increases.
Because you don’t ovulate when you take the combined pill, you don’t have a real period every month. Instead, you get a withdrawal bleed, which can be much lighter and shorter than a period. So if you have problems with heavy, painful periods, taking the combined pill can help. It can also protect against cancers of the ovary, womb and colon, plus some pelvic infections.
Anything else to know about?
It must be taken at the same time every day and on the correct days to be effective. If you don’t take it at the same time every day, or if you miss one, have any vomiting or severe diarrhoea, or have to take other types of medication, then you could get pregnant. It isn’t suitable for those with certain medical conditions. You should see your GP or someone experienced to see if you can take this kind of pill. There is a very low risk of serious side effects including blood clots and cervical cancer. Minor side effects include mood swings, breast tenderness and headaches. There is no evidence that the combined pill causes weight gain. If you aren't in a monogamous (faithful) relationship you should help protect yourself against sexually transmitted infections by using condoms as well as the combined pill however you may need to do this even if you think you are in a faithful relationship.