The combined oral contraceptive pill is usually just called "the pill". It contains artificial versions of the female hormones oestrogen and progesterone, which women produce naturally in their ovaries.
A woman can get pregnant if a man’s sperm reaches one of her eggs (ova). Contraception tries to stop this happening by keeping the egg and sperm apart or by stopping egg production. One method of contraception is the combined pill.
The hormones in the pill prevent your ovaries from releasing an egg (ovulating). They also make it difficult for sperm to reach an egg, or for an egg to implant itself in the lining of the womb. The pill is usually taken to prevent pregnancy, but can also be used to treat painful periods, heavy periods, premenstrual syndrome (PMS) and endometriosis.
The pill prevents the ovaries from releasing an egg each month (ovulation). It also:
Although there are many different brands of pill, there are 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, Brevinor 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. Binovum and Logynon are examples of this type of pill.
You can get contraception at:
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 and Logynon ED are examples of this type of pill.
Follow the instructions that come with your packet. If you have any questions about how to take the pill, ask your doctor, 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.
If you start the pill on any other day of your cycle, you will not be protected from pregnancy straight away and will need additional contraception until you have taken the pill for seven days.
For monophasic combined pills (pills all the same colour and with the same level of hormones), it is normally fine to start a new pack of pills straight after your last one – for example, if you want to delay your period for a holiday.
However, avoid taking more than two packs together unless advised to by a doctor or nurse. This is because you may have breakthrough bleeding as the womb lining sheds slightly. Some women find they feel bloated if they run several packs of the pill together.
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:
A pill is late when you have forgotten to take it at your usual time. You have missed a pill when it is more than 24 hours since the time you should have taken it. Missing one pill anywhere in your pack or starting the new pack one day late isn’t a problem, as you will still be protected against pregnancy (known as having contraceptive cover).
However, missing two or more pills, or starting the pack two or more days late (more than 48 hours late) may affect your contraceptive cover. In particular, if you make the seven-day pill-free break longer by forgetting two or more pills, your ovaries might release an egg and there is a risk of getting pregnant. This is because your ovaries are not getting any effect from the pill during the seven-day break.
If you miss a pill, follow the advice below. If you are not sure what to do, continue to take your pill and use another method of contraception, such as condoms, and seek advice as soon as possible.
If you have missed one pill, anywhere in the pack:
If you have missed two or more pills (you are taking your pill more than 48 hours late) anywhere in the pack:
You may need emergency contraception if you have had unprotected sex in the previous seven days and have missed two or more pills (you are taking your pill more than 48 hours late) in the first week of a pack.
Get advice from your contraception clinic, doctor or pharmacist about this.
If there are seven or more pills left in the pack after the last missed pill:
If there are fewer than seven pills left in the pack after the last missed 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 while you're ill and for two days after recovering.
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 doctor or contraception nurse for more information, or if your sickness or diarrhoea continues.
If there are no medical reasons why you cannot take the pill and you do not 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 doctor, 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 start the pill on day 21 after the birth. 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 a baby less than six months old, taking the pill can reduce your flow of milk. It is recommended that you use a different method of contraception until you stop breastfeeding.
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 progestogen by your liver, reducing the effectiveness of the pill.
Examples of enzyme inducers are:
Your doctor 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 deep vein thrombosis (clot in your leg), pulmonary embolus (clot in your lung), stroke or heart attack. The risk of getting a blood clot is very small, but your doctor will check if you have certain risk factors that make you more vulnerable before prescribing the pill.
The pill can be taken with caution if you have one of the risk factors below, but you should not 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 endometrium (lining of the womb) cancer, ovarian cancer and colon cancer.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.