The progestogen-only pill (POP)

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Illustration of a blister of contraceptive pillsProgestogen-only pills (POPs) contain a progestogen hormone. This is similar to the natural progesterone produced by the ovaries.

Different POPs contain different types of progestogen. POPs with a type called desogestrel are named where relevant on this page. If you’re not sure what type of progestogen is in your POP, check the patient information leaflet inside your pack or ask your doctor or nurse. POPs are different to combined pills because they don’t contain the hormone estrogen.

Your Guide to the Progestogen-only Pill (PDF)

How effective any contraceptive is depends on how old you are, how often you have sex and whether you follow the instructions.

If 100 sexually active women don’t use any contraception, 80 to 90 will become pregnant in a year.

If the POP is always used perfectly, according to instructions, it’s over 99% effective. This means that less than one POP user in 100 will get pregnant in one year.

If the POP is not always used according to instructions, about nine in 100 POP users will get pregnant in one year.

The POP works in a number of ways.

  • The main action of desogestrel POPs is to stop your ovaries releasing an egg (ovulation). Other types of POP sometimes stop you releasing an egg.
  • All POPs work by thickening the mucus from your cervix (neck of the womb). This makes it difficult for sperm to move through it and reach an egg.
  • All POPs make the lining of your uterus (womb) thinner so it’s less likely to accept a fertilised egg.

You can go to a contraception or sexual health clinic, or general practice. If you prefer not to go to your own general practice, or if they don’t provide contraceptive services, they can give you information about another practice or clinic. All treatment is free and confidential. You don’t need to have a vaginal or breast examination or cervical screening test when you’re first prescribed the POP

Most women can use the POP. A doctor or nurse will ask you about your own and your family’s medical history. Do mention any illness or operations you’ve had. Some of the conditions which may mean you shouldn’t use the POP are:

  • you think you might already be pregnant
  • you take certain medicines.

You have now or had in the past:

  • heart disease or a stroke
  • disease of the liver
  • breast cancer.

If you’re healthy and there are no medical reasons for you not to take the POP, you can take it until your menopause or until you’re 55 years old.

Some of the advantages of the POP are:

  • it’s useful if you can’t take estrogens, like those found in the combined pill, contraceptive patch or contraceptive vaginal ring
  • you can use it at any age, but it’s especially useful if you smoke and are 35 or over
  • it may help with premenstrual symptoms and painful periods
  • you can use it if you’re breastfeeding.

There are no serious side effects with the POP. However:

  • It’s common for your periods to change while you’re taking the POP. Bleeding may be irregular, light, more frequent, last longer or stop altogether. This may settle down and isn’t harmful. If you have any concerns, see your doctor or nurse. Changing to a different POP may help.
  • The POP doesn’t protect you against sexually transmitted infections, so you may need to use condoms as well.
  • You have to remember to take the pill at the same time every day.
  • You may get some side effects when you first start taking the POP, such as spotty skin, breast tenderness and headaches. These may stop within a few months.

The POP is a very safe pill to take but there are some risks.

  • Some POP users may develop small fluid-filled cysts on their ovaries. These aren’t dangerous and don’t usually need to be removed. Often there are no symptoms, but some people may have pelvic pain. These cysts usually disappear without treatment.
  • Research about the risk of breast cancer and hormonal contraception is complex and contradictory. Research suggests women who use hormonal contraception may have a small increase in the risk of being diagnosed with breast cancer compared to women who don’t use hormonal contraception.
  • If you do become pregnant while you’re using the POP there’s a risk of you having an ectopic pregnancy (see below, What should I do if I think I'm pregnant?).

You can start the POP any time in your menstrual cycle if it’s certain you’re not pregnant.

If you start the POP on the first day of your period you’ll be protected from pregnancy immediately.

You can also start the POP up to and including the fifth day of your period and you’ll be protected from pregnancy immediately.

However, if you have a short menstrual cycle with your period coming every 23 days or less, starting the POP as late as the fifth day of your period may not give you immediate contraceptive protection. This is because you may ovulate (release an egg) early in your menstrual cycle. You may wish to talk to your doctor or nurse about this and whether you need additional contraception for the first two days.

If you start the POP at any other time in your menstrual cycle, use another contraceptive method, such as condoms, for the first two days of pill-taking.

The POP can be started any time after the birth. If you start the POP after day 21 you’ll need to use additional contraception for two days. You can breastfeed while you’re taking the POP. A tiny amount of hormone enters your breast milk, but research has shown this won’t harm your baby.

You can start taking the POP immediately after a miscarriage or abortion. You’ll be protected from pregnancy immediately.

When taking your first pill choose a convenient time to take it. This can be any time of the day. Once you’ve chosen a time you must then take one POP each day at this same time until you finish all the pills in the pack.

You then start a new pack the next day so there are no breaks between packs.

For your pill to work it’s important not to take it more than three hours (12 hours for POPs with desogestrel) after your chosen time. If you remember later than this, see below section What do I do if I miss a pill?.

If you’re changing to another POP (or from the combined pill) you may be advised to start the new pill immediately or start the day after you take your last pill. Don’t have a break between packs. There’s no need to wait for your period. You’ll then continue to have protection from pregnancy.

If you vomit within two hours of taking the POP, it won’t have been absorbed by your body. Take another pill as soon as you feel well enough. As long as you’re not sick again your contraception won’t be affected. Take your next pill at the normal time. If you continue to be sick, seek advice.

If you have very severe diarrhoea that continues for more than 24 hours, this may make the POP less effective. Keep taking your pill at the normal time, but treat each day that you have severe diarrhoea as if you’d missed a pill. Follow the missed pill instructions below.

If you’re more than three hours* late:

  • Take a pill as soon as you remember. If you’ve missed more than one, only take one.
  • Take your next pill at the usual time. This may mean taking two pills in one day. This isn’t harmful.
  • You’re not protected from pregnancy. Continue to take your pills as usual but use an additional method of contraception, such as condoms, for the next two days.
  • If you’ve had unprotected sex during this time you may need emergency contraception. Seek advice immediately.

If you're less than three hours* late:

  • Take a pill as soon as you remember. Take your next pill at the usual time. You’re protected from pregnancy.

*12 hours if you’re taking a desogestrel POP

If you’re given medicines by a doctor, nurse or hospital always say you’re taking the POP. Commonly used antibiotics don’t affect the POP.

Medicines such as some of those used to treat epilepsy, HIV and TB, and the complementary medicine St John’s Wort may make the POP less effective. These types of drugs are called enzymeinducers. If you take these medicines, talk to your doctor or nurse about how to take the POP. You may need to use a different method of contraception.

If you took all your pills correctly and you didn’t have an upset stomach or take any other medicines which might affect the POP, then it’s unlikely you’re pregnant. Continue to take your pills as normal. There’s no evidence that if you take the POP when you’re pregnant it will harm the baby. If you’re worried, ask your doctor or nurse for advice or do a pregnancy test.

Taking the POP doesn’t affect a pregnancy test. If you do become pregnant there’s a risk of ectopic pregnancy (where the pregnancy develops outside your uterus (womb), usually in a fallopian tube). Seek medical advice as soon as possible if you have a sudden or unusual pain in your lower abdomen (this might be a warning sign of an ectopic pregnancy) or if you think you might be pregnant.

You can try to get pregnant as soon as you stop taking the POP. You can stop taking it at any time. Ideally you should wait for one natural period before trying to get pregnant, so you’ll need to use another method of contraception, such as condoms. This means the pregnancy can be dated more accurately and you can start pre-pregnancy care such as taking folic acid and stopping smoking. You can ask your doctor or nurse for advice. Don’t worry if you get pregnant sooner, it won’t harm the baby.

When you first start the POP you can be given up to a 12 months’ supply. You should go back to the doctor or nurse if you have any problems or concerns and when you need to get a new supply of the POP.

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This website can only give you general information. The information is based on evidence-guided research from the World Health Organization and The Faculty of Sexual and Reproductive Healthcare of the Royal College of Obstetricians and Gynaecologists. All methods of contraception come with a Patient Information Leaflet which provides detailed information about the method.

Remember – contact your doctor, practice nurse or a contraception clinic if you're worried or unsure about anything.