The pill prevents the ovaries from releasing an egg each month (ovulation). It also:
The pill is over 99% effective if used correctly. Some women find it difficult to take the pill at the same time every day, and it’s less effective if not used correctly. Other methods of contraception are better at preventing pregnancy, such as the IUD, IUS, implant and injection.
There are many different brands of pill, made up of three main types:
This is the most common type. Each pill has the same amount of hormone in it. One pill is taken each day for 21 days and then no pills are taken for the next seven days. Microgynon, Marvelon, Yasmine and Cilest are examples of this type of pill.
Phasic pills contain two or three sections of different coloured pills in a pack. Each section contains a different amount of hormones. One pill is taken each day for 21 days and then no pills are taken for the next seven days. Phasic pills need to be taken in the right order. Logynon is an example of this type of pill.
There are 21 active pills and seven inactive (dummy) pills in a pack. The two types of pill look different. One pill is taken each day for 28 days with no break between packets of pills. Every day pills need to be taken in the right order. Microgynon ED is an example of this type of pill.
Follow the instructions that come with your packet. If you have any questions, ask your GP, practice nurse or pharmacist.
It’s important to take the pills as instructed, because missing pills or taking them at the same time as certain medicines may make them less effective.
Most women can start the pill at any time in their menstrual cycle. There is special guidance if you have just had a baby, abortion or miscarriage.
You may need to use additional contraception during your first days on the pill – this depends on when in your menstrual cycle you start taking it.
If you start the combined pill on the first day of your period (day one of your menstrual cycle) you will be protected from pregnancy straight away. You will not need additional contraception.
If you start the pill on the fifth day of your period or before, you will still be protected from pregnancy straight away, unless you have a short menstrual cycle (your period is every 23 days or less). If you have a short menstrual cycle, you will need additional contraception, such as condoms, until you have taken the pill for seven days.
You will not be protected from pregnancy straight away and will need additional contraception until you have taken the pill for seven days.
If you start the pill after the fifth day of your cycle, make sure you have not put yourself at risk of pregnancy since your last period. If you’re worried you’re pregnant when you start the pill, take a pregnancy test three weeks after the last time you had unprotected sex.
If you miss a pill or pills, or you start a pack late, this can make the pill less effective at preventing pregnancy. The chance of getting pregnant after missing a pill or pills depends on:
Find out what to do if you miss a combined pill.
If you vomit within two hours of taking the combined pill, it may not have been fully absorbed into your bloodstream. Take another pill straight away and the next pill at your usual time.
If you continue to be sick, keep using another form of contraception until you’ve taken the pill again for seven days without vomiting.
Very severe diarrhoea (six to eight watery stools in 24 hours) may also mean that the pill doesn’t work properly. Keep taking your pill as normal, but use additional contraception, such as condoms, while you have diarrhoea and for two days after recovering.
Speak to your GP or contraception nurse or call NHS 111 for more information, or if your sickness or diarrhoea continues.
If there are no medical reasons why you cannot take the pill, and you don’t smoke, you can take the pill until your menopause. However, the pill is not suitable for all women. To find out whether the pill is right for you, talk to your GP, practice nurse or pharmacist.
You should not take the pill if you:
You should also not take the pill if you have (or have had):
If you have just had a baby and are not breastfeeding, you can most likely start the pill on day 21 after the birth but you will need to check with your doctor. You will be protected against pregnancy straight away.
If you start the pill later than 21 days after giving birth, you will need additional contraception (such as condoms) for the next seven days.
If you are breastfeeding, you’re not advised to take the combined pill until six weeks after the birth.
If you have had a miscarriage or abortion, you can start the pill up to five days after this and you will be protected from pregnancy straight away. If you start the pill more than five days after the miscarriage or abortion, you’ll need to use additional contraception until you have taken the pill for seven days.
Some advantages of the pill include:
Some disadvantages of the pill include:
Some medicines interact with the combined pill and it doesn’t work properly. Some interactions are listed on this page, but it is not a complete list. If you want to check your medicines are safe to take with the combined pill, you can:
The antibiotics rifampicin and rifabutin (which can be used to treat illnesses including tuberculosis and meningitis) can reduce the effectiveness of the combined pill. Other antibiotics do not have this effect.
If you are prescribed rifampicin or rifabutin, you may need additional contraception (such as condoms) while taking the antibiotic. Speak to your doctor or nurse for advice.
The combined pill can interact with medicines called enzyme inducers. These speed up the breakdown of hormones by your liver, reducing the effectiveness of the pill.
Examples of enzyme inducers are:
Your GP or nurse may advise you to use an alternative or additional form of contraception while taking any of these medicines.
There are some risks associated with using the combined contraceptive pill. However, these risks are small and, for most women, the benefits of the pill outweigh the risks.
The oestrogen in the pill may cause your blood to clot more readily. If a blood clot develops, it could cause:
The risk of getting a blood clot is very small, but your doctor will check if you have certain risk factors that before prescribing the pill.
The pill can be taken with caution if you have one of the risk factors below. It is unlikely you would be advised to take it if you have two or more risk factors. These include:
Research is ongoing into the link between breast cancer and the pill. Research suggests that users of all types of hormonal contraception have a slightly higher chance of being diagnosed with breast cancer compared with women who do not use them. However, 10 years after you stop taking the pill, your risk of breast cancer goes back to normal.
Research has also suggested a link between the pill and the risk of developing cervical cancer and a rare form of liver cancer. However, the pill does offer some protection against developing womb (endometrial) cancer, ovarian cancer and colon cancer.
Contraception is free to all women and men through the NHS. Places where you can get contraception include:
If you want advice about changing your contraceptive pill, you can visit your GP, contraceptive nurse (sometimes called a family planning nurse), or sexual health clinic.
You should not have a break between different packs, so you will usually be advised to start the new pill immediately or wait until the day after you take the last of your old pills.
You may also be advised to use alternative methods of contraception during the changeover, as the new pill may take a short time to take effect.
Contraception services are free and confidential, including for people under the age of 16.
If you’re under 16 and want contraception, the doctor, nurse or pharmacist won’t tell your parents (or carer) as long as they believe you fully understand the information you’re given, and your decisions.
Doctors and nurses work under strict guidelines when dealing with people under 16. They’ll encourage you to consider telling your parents, but they won’t make you.
The only time that a professional might want to tell someone else is if they believe you’re at risk of harm, such as abuse. The risk would need to be serious, and they would usually discuss this with you first.