If 100 people who could get pregnant don’t use any contraception, 80 to 90 of them will get pregnant in a year.

If the combined pill is:

• Not always used perfectly, according to instructions, it’s about 93% effective. About 7 in 100 people using the pill will get pregnant in 1 year. Most pill users don’t take it perfectly all the time.

• Always used perfectly, it’s over 99% effective. This means fewer than 1 in 100 people who use the pill perfectly will get pregnant in 1 year.

The most effective methods of contraception are those you don’t have to remember, such as the implant, the hormonal IUD (hormonal coil) or copper IUD (copper coil). These are called long-acting reversible contraceptives (LARC). For more information, ask your healthcare professional or see FPA’s guide to LARCs.

The hormones in the pill:

• stop the ovaries from releasing an egg each month (ovulation)

• thicken the mucus in your cervix (entrance to the womb) so it’s difficult for sperm to move through it and reach an egg

• make the lining of your uterus (womb) thinner so a fertilised egg is less likely to implant.

Because you don’t ovulate and the lining of the womb doesn’t get thicker, you won’t have periods while you’re using the pill. If you have a 4-day or 7-day break between pill packs, you’ll still get some period-like bleeding called a withdrawal bleed – also see Will my periods change?

You can get the pill for free from:

• a contraception or sexual health clinic
• a GP surgery
• some young people’s services
• many pharmacies; a pharmacy may also be able to give you a short supply if you run out of pills from your usual provider

In some areas of the UK, you can order the pill for free from an online sexual health service. They can send it by post and may offer a click and collect service. You usually need to be 16 or over and be able to give a recent blood pressure measurement.

All advice and treatment from these services is free and confidential.

You can buy the pill from some online pharmacies, private online services or private clinics.

You don’t need a vaginal or breast examination or cervical screening (smear test) before you start using the pill.

Not everyone can use the combined pill.

Your healthcare professional or online service will ask about your own and your family’s medical history. This is to make sure the pill is OK for you. Do mention any medical conditions, allergies or operations you’ve had and any medicines you’re taking.

The pill may not be suitable for you if:

• you think you might be pregnant
• you smoke or vape and are aged 35 or over
• you’re aged 35 or over and stopped smoking or vaping less than a year ago
• you’re overweight, with a body mass index (BMI) of 35 or more
• you take certain medicines – see Will other medicines affect the pill?
• you’re breastfeeding a baby less than 6 weeks old – see I’ve just had a baby. Can I use the pill?
• you’ve had weight loss surgery
• you have a condition that causes malabsorption issues (where your gut can’t absorb nutrients effectively) such as Crohn’s disease

The pill may not be suitable for you if you’ve ever had:

• thrombosis (a blood clot) in any vein or artery, including your lungs or you have more than one condition that increases your risk of having a blood clot
• an immediate family member who had a blood clot
• heart disease or a stroke
• breast cancer or a gene mutation that’s associated with breast cancer
• systemic lupus erythematosus with positive antiphospholipid antibodies
• a heart abnormality or circulatory disease, including high blood pressure
• migraine with aura
• gallbladder disease or liver disease
• diabetes with complications
• chronic kidney disease
• an organ transplant

It may not be suitable if you’re:

• having major surgery – see Are there any risks?
• immobile for a long period of time or use a wheelchair
• at high altitude (more than 4,500m) for more than a week

If you’re healthy, don’t smoke or vape and there are no medical reasons for you not to use the pill, you can use it until you’re aged 50. You’ll then need to use another method of contraception until your menopause.

Some of the advantages of the pill are:

• It usually makes your bleeds regular, lighter and less painful
• You can choose not to have a monthly bleed
• It may help with premenstrual symptoms
• It reduces the risk of cancer of the ovary, uterus and colon (bowel)
• It improves acne in some people
• It may reduce menopausal symptoms
• It may reduce the risk of recurrent endometriosis after surgery
• It helps with problems associated with polycystic ovary syndrome (PCOS)

There are some possible serious risks – see below – Are there any risks?

In addition:

• You may get temporary side effects at first, including headaches, nausea, breast tenderness and mood changes. If side effects don’t stop within a few months, talk to your healthcare professional. Changing the type of pill may help
• Breakthrough bleeding and spotting (unexpected vaginal bleeding on pill-taking days) is common in the first few months of using the pill
• There’s a small chance your blood pressure may increase
• You need to remember to take the pill every day
• The pill doesn’t protect you from sexually transmitted infections, so you may want to use condoms too

The pill can have some serious risks. These are not common but can happen to anyone.

For most people, the benefits of the pill outweigh the possible risks.

Your contraception provider will ask some questions to check whether you could be at higher risk.

If you develop any new conditions, always tell a doctor, nurse or pharmacist so they can check it’s still safe for you to use the pill.

• A very small number of pill users may develop a blood clot in a vein, including deep vein thrombosis, a blood clot in an artery, pulmonary embolism (a blood clot in a lung), heart attack or stroke. Do not use the pill if you’ve ever had a blood clot, or you have other conditions that increase your risk of a blood clot.

• The risk of a blood clot is greatest if any of these apply: you smoke, you’re very overweight, you have a thrombophilia (blood clotting disorder), are immobile for a long period of time or use a wheelchair, have high blood pressure, have migraines with aura or have an immediate family member who had a blood clot in their leg, lung or artery.

• Research suggests that use of any hormonal contraception (including the combined pill) does slightly increase breast cancer risk among current and recent users, but the risk remains small. This increased risk reduces over time after stopping the pill and is undetectable 10 years after stopping.

• Research suggests there’s a small increase in the risk of developing cervical cancer with longer use of the combined pill. This risk reduces over time after stopping the pill and is undetectable 10 years after stopping.

Call 111 or see a doctor straight away if you have any of these:

• pain in your chest or upper back
• breathlessness
• coughing up blood
• throbbing pain and/or redness or swelling in a leg or arm
• weakness, numbness, or bad ‘pins and needles’ in an arm or leg
• an unusual headache or migraine that is worse than usual
• your heart is beating very fast

Call 999 or go to an Emergency Department (A&E) if you have any of these:

• more than one of the above list
• sudden severe difficulty breathing
• sudden problems with your speech or eyesight

If you go into hospital for an operation or have an accident which affects the movement of your legs, tell the doctor you’re using the combined pill.

You may need to change to a different method of contraception or need treatment to reduce the risk of a blood clot.

You may be advised to stop the pill 4 weeks before any planned surgery and use a different method.

If you’re given medicine by a healthcare professional, always tell them if you’re using the combined pill.

Commonly used antibiotics do not affect the pill.

Some medicines may make the combined pill less effective at preventing pregnancy, including:

• Medicines called enzyme-inducers may make the pill less effective. These include some medicines used to treat epilepsy, migraine, HIV and TB
• The herbal medicine St John’s Wort
• Some weight-loss injection medicines (also sometimes used to treat diabetes) such as tirzepatide (Mounjaro). When starting tirzepatide, you need to use condoms as well as the pill for the first 4 weeks. You also need to use condoms as well as the pill for 4 weeks after each dose increase of tirzepatide
• An antifungal medicine called griseofulvin
• A medicine called lamotrigine, sometimes used to treat bipolar disorder or epilepsy

If you take any medicines that may affect the pill, talk to your healthcare professional. Consider changing to contraception that won’t be affected by the medicines you’re taking, such as the hormonal IUD, copper IUD or injection.

Always check with a healthcare professional before starting any new medicines, herbal remedies, or supplements.

You won’t have your usual periods. The pill stops you from releasing an egg each month. It also stops the lining of the womb getting thicker each month. So your body doesn’t need periods while you’re on the pill.

If you have a break between pill packs, you’ll usually still get some period-like bleeding. This is called a withdrawal bleed. It’s caused by a drop in your hormone levels after a few days without getting hormones from the pill. This causes your body to shed some blood from the womb lining. Because the pill keeps the lining thin, a withdrawal bleed is often lighter, shorter and less painful than your usual periods.

The pill was designed to give you a hormone-free break each month as it was thought women would want to have a monthly bleed. So most pill instructions suggest a 7-day break. If you take a monophasic pill this break is not needed. You can choose a shorter 4-day break or miss the break completely and not have a withdrawal bleed. Also see below – How do I take the pill?

There are no known benefits of hormone-free breaks and no known risks to missing out a break and withdrawal bleed.

You can miss out the hormone-free break and withdrawal bleed every month or just occasionally.

Missing or shortening the hormone-free break:

• Could help if you get heavy or painful bleeding, headaches or mood swings during the break
• Could reduce your risk of pregnancy. This is because if you forget your pill just before or just after a break, you’re more at risk of pregnancy than at other times

Bleeding is very common when you first start using the pill. It isn’t usually anything to worry about. It may take up to 3 months to settle down.

It’s important to keep taking the pill according to instructions, even if the bleeding is as heavy as a withdrawal bleed.

If you’re taking the pill continuously, it’s normal to get some bleeding, see How do I take the pill?

Bleeding may also be due to other causes, such as not taking the pill correctly or a sexually transmitted infection.

If bleeding doesn’t settle down or starts after you’ve used the pill for some time, get advice from your healthcare professional.

• If you’ve used the pill correctly, haven’t taken any medicines which might affect it, and haven’t been sick or had diarrhoea, then it’s very unlikely you’re pregnant. Also see Will other medicines affect the pill?

• Keep using the pill as usual and do a pregnancy test. If you’re worried, ask your healthcare professional for advice.

• Using the pill won’t affect a pregnancy test. If you are pregnant, using the pill won’t end the pregnancy and won’t harm the fetus.

Research hasn’t shown that the pill causes weight gain.

Your weight may change due to fluid retention or other reasons not related to the pill.

You cannot start the combined pill until 3 to 6 weeks after you’ve had your baby. This is because of the increased risk of blood clots soon after having a baby.

If you’re breastfeeding, do not start the pill for the first 6 weeks. This gives breastfeeding time to establish. Your healthcare professional, including a midwife or health visitor, can discuss the best time to start the pill.

You can get pregnant again as early as 3 weeks after having a baby. Use a different method of contraception until it’s suitable to start the combined pill.

Yes. If you start most types of combined pill on or before day 5 after a miscarriage or abortion, you’ll be protected from pregnancy straight away.

If you start later than day 5, use condoms or avoid sex for the first 7 days of pill-taking.

It’s easy to change from the pill to a different method or to change from one pill to another.

Talk to your healthcare professional. You may need to miss any planned breaks or inactive pills or use other contraception for a short time.

When you stop using the pill, your fertility will go back to whatever’s normal for you. It’s possible to get pregnant before you have your first period after stopping the pill.

Don’t worry if your periods don’t start straight away. For some people it can take a few months after stopping the pill.

If you don’t want to get pregnant, it’s best to stop taking the pill at the end of a pack (not including any inactive pills). Use another method of contraception as soon as you stop the pill.

If you don’t want to wait until the end of a pack, ask your healthcare professional for advice because you can risk getting pregnant if you’ve had sex recently.

If you want to get pregnant, aim to start pre-pregnancy care – such as taking folic acid and vitamin D, and stopping smoking and drinking alcohol – before you stop using the pill. Ask your healthcare professional for advice or see tommys.org/pregnancy-information

You can stop at any time and try to get pregnant straight away. You can also wait until you’ve had your first period after stopping so it’s easier to work out when you got pregnant.

When you first start the pill, or you get new supplies, you’ll be advised when to get your next review. Most people will need a review every 12 months, but some people may need a review more often than this.

A review may be done face to face or may be done online or by phone for some people.

Your medical history, blood pressure and weight need to be checked at least once a year while you’re using the pill.

For online and phone reviews, you’ll need to give recent height, weight and blood pressure measurements. Your blood pressure could be taken by a healthcare professional (for example at a pharmacy or GP surgery), at a self-testing station (for example at a GP surgery or sexual health clinic) or using a home blood pressure machine (check with your healthcare professional which machines are OK to use).

It’s important to get advice from a healthcare professional as soon as possible if you have any problems or concerns, develop new health problems or want to change to a different method of contraception. You don’t need to wait until your next review.

No, you don’t need a break and the hormones do not build up. There are no known benefits to your health or fertility from taking a break.

You can start the pill any time in your menstrual cycle if you’re sure you’re not pregnant.

If you start the pill:

• On the first day of your period, you’ll be protected from pregnancy straight away.

• Up to, and including, the fifth day of your period, you’ll usually be protected from pregnancy straight away.

• For a few types of pill, or if you have a very short cycle or a cycle that changes, you may need additional contraception at first. Your pill provider should discuss this with you.

• At any other time in your menstrual cycle, you’ll need to use condoms or avoid sex for the first 7 days of pill-taking.

There are different ways to take the pill, depending on the type and your preference.

Most pill instructions tell you to take a 7-day pill-free break between packs. This isn’t needed. You can have a 4-day break, or miss out the break.

Having no break or a shorter break can help lower your risk of pregnancy. This is because if you miss a pill just before or just after a break, you’re more at risk of pregnancy than at other times.

If you have a break, you’ll usually have a withdrawal bleed. If you don’t have a break, you won’t usually have a withdrawal bleed. Also see Will my periods change?

Having no break or a shorter break can help if you get heavy or painful bleeding, headaches, or mood swings during the break.

There are many different brands of pill. Most of them are one of 3 types, used slightly differently.

You’ll usually be given a monophasic pill. If you’re given a different type, your healthcare professional should discuss this with you.

Monophasic pills

This is the most common type of pill. There are 21 pills in a pack. Each pill is the same.

There are different ways to take it, so you can choose a bleeding pattern that works for you.

• 1 pill a day for 21 days then no pills for the next 4 or 7 days.

• You’ll usually have a withdrawal bleed during the pill-free break. Start taking the pill again on the fifth or eighth day even if you’re still bleeding.

• You can miss out a pill-free break at any time, if you don’t want a withdrawal bleed that month

• 1 pill a day for 9 weeks (3 packs of pills) then no pills for the next 4 or 7 days.

• This is called extended use or tricycling. You’ll usually have a withdrawal bleed during the pill-free break. Start taking the pill again on the fifth or eighth day even if you’re still bleeding.

• Taking the pill this way means you’ll only have a bleed once every 10 weeks

• 1 pill every day with no break.

• This is called continuous pill-taking. You won’t have a regular withdrawal bleed but you may still get some bleeding. It may be occasional or more frequent. This is likely to reduce over time if you keep taking the pill continuously

• 1 pill every day for 21 days or longer. If you get bleeding that’s unacceptable to you and lasts for 3 to 4 days, have a 4-day pill-free break.

• This is called flexible extended use. Start taking the pill again on the fifth day, even if you’re still bleeding. This can help manage the bleeding. Restart with the pill marked with the correct day of the week and take a pill every day for at least 21 days before taking your next break.

You can take the pill without a break for as long as you like, as long as a healthcare professional doesn’t advise you to stop.

EveryDay monophasic pills

You get a pack of 28 pills. There are 21 or 24 active pills (with hormones) and 7 or 4 inactive pills (without hormones). The active and inactive pills look different to each other.

Take 1 pill every day, starting with the active pills and ending with the inactive pills. You do not have a break between packs.

On days you take the inactive pills you’ll usually get a withdrawal bleed. When you finish a pack, start a new pack the next day even if you’re still bleeding.

You must take EveryDay pills in the right order. They come with sticky strips of paper with the days of the week marked on them. These help you keep track of your pill taking.

You can choose not to have a withdrawal bleed by missing out the inactive pills. Ask your healthcare professional about this first.

Phasic 21-day pills

A phasic pill might be considered if you do not get on well with monophasic pills.

Phasic pills have different amounts of hormones, designed to mimic a menstrual cycle. They must be taken in the right order at about the same time each day.

There are 2 or more 3 sections of different coloured pills in the pack. Take the first pill from the section of the pack marked ‘start’. Take 1 pill every day for 21 days until the pack is finished.

You then have a 7-day break with no pills. You’ll usually have a withdrawal bleed. Start your next pack on the eighth day even if you’re still bleeding.

There are also EveryDay phasic pills with 28 pills in a pack. You take 7 inactive pills instead of having a 7-day break.

Yes. You’re protected if:

• you’ve taken all the pills correctly and
• you start the next pack on time and
• nothing else has happened that might make the pill less effective, such as vomiting

It’s very important to take your pill as instructed. When taking your first pill, choose a convenient time. This can be any time of day.

Taking a pill at the same time each day will help you remember to take it regularly.

Forgetting pills or starting a pack late can make the pill less effective.

The chance of pregnancy after missing pills depends on:

• when pills are missed
• how many pills are missed
• the way you take the pill

Forgetting 1 pill anywhere in a pack isn’t a problem. You’ll still be protected from pregnancy.

Forgetting 2 or more pills or starting a new pack late may mean you’re at risk of pregnancy. See Missed or late pills: an easy guide

If it’s been 48 hours or more since you last took a pill and you’re not on a pill-free break, then you’ve “missed” a pill.

If you’re late starting a new pack after a pill-free break, you may also have missed a pill.

Take a pill as soon as you remember and see Missed or late pills: an easy guide.

• If you vomit within 3 hours of taking a pill, it won’t have been absorbed by your body, so it’s as if you hadn’t taken it. You’ll still be protected from pregnancy as long as no more pills are missed.

• If you continue to be sick, get advice from a doctor, nurse or pharmacist.

• If you have very severe diarrhoea lasting for 24 hours or more, this may make the pill less effective. Keep taking your pill at the normal time but treat each day of severe diarrhoea as if you’d missed a pill.

See Missed or late pills: an easy guide below.

• Use this guide if you take a monophasic pill with 21 pills in each pack
• For any other type of pill, follow the guide that came with your pill or talk to a healthcare professional

When did you last take your pill?

I’m late restarting after a pill-free break

If it’s LESS THAN 9 full days since the time you last took a pill:

• • • Start a new pack now
    • Continue taking the rest of the pack as usual

If it’s 9 OR MORE full days since the time you last took a pill:

• • • Start a new pack now
    • Use condoms or avoid sex for the next 7 days
    • You may need emergency contraception and a follow-up pregnancy test if you had unprotected sex in the pill-free break. Talk to a doctor, nurse or pharmacist as soon as possible

If it’s up to 48 hours since your last pill

• • • Take your next pill now
    • Continue taking the rest of the pack as usual

If it’s 48 to 72 hours since your last pill

• • • You’ve missed 1 pill
    • Take the last pill you missed now
    • Continue taking the rest of the pack as usual

If you’re in the first week after a pill-free break, emergency contraception isn’t usually needed unless you’ve already missed a pill this week OR you missed a pill in the 7 days before the pill-free break.

If you’re in any other week, emergency contraception isn’t usually needed, unless you’ve missed another pill in the past 7 days.

If it’s 72 hours (3 days) to 7 days since your last pill

• • • You’ve missed 2 or more pills
    • Take the last pill you missed now
    • Leave any earlier missed pills
    • Continue taking the rest of the pack as usual AND use condoms or avoid sex for the next 7 days
    • If you’re due to start a pill-free break within the next 7 days, don’t take the break

If you’re in the first week after a pill-free break and you had unprotected sex during the break or during week 1, you may need emergency contraception and a follow-up pregnancy test. Get advice from a healthcare professional.

If you’re in any other week, emergency contraception isn’t usually needed unless you’ve also missed another pill in the past 7 days.

If it’s more than 7 days since your last pill and it’s not a planned break

• • • You’ve missed a lot of pills and could be at risk of pregnancy
    • Start a new pack now
    • Continue taking pills as usual AND use condoms or avoid sex for the next 7 days
    • If you’ve had unprotected sex, you may need emergency contraception and you do need a pregnancy test. Talk to a doctor, nurse or pharmacist as soon as possible

If you think you might miss more pills, talk to your doctor or nurse about contraception you don’t have to remember.

If you’ve had sex without contraception, or think your method might have failed, you can use emergency contraception.

Try to get emergency contraception as soon as possible after unprotected sex to give it the best chance of working.

A copper intrauterine device (IUD) is the most effective option. Some people will get pregnant even when they take emergency pills correctly.

• An emergency IUD (copper coil) can be fitted up to 5 days after sex, or up to 5 days after the earliest time you could have ovulated (released an egg).

• An emergency contraceptive pill with the active ingredient ulipristal acetate (UPA) can be taken up to 5 days (120 hours) after sex. UPA is not usually recommended if the combined pill has been taken in the last 7 days because the combined pill could make the UPA pill less effective. The combined pill should not usually be taken for 5 days after taking a UPA pill.

• An emergency contraceptive pill with the hormone levonorgestrel can be taken up to 3 days (72 hours) after sex.

Emergency pills are available for free from sexual health clinics, GP surgeries and many pharmacies, or you can buy them from most pharmacies.

For more details – read the FPA guide to emergency contraception.