The progestogen only pill is different to the combined oral contraceptive because instead of containing oestrogen and progestogen, it only contains progestogen. There are different types of POP, some containing different progestogens.
How effective is it?
If the POP is taken according to the instructions it is over 99% effective.
This means that less than 1 woman in a 100 will get pregnant in a year.
How does it work?
The main way the POP works is by making the mucous at the neck of the womb thick. This means it is difficult for sperm to enter the womb. Sometimes the POP can stop the ovaries releasing eggs. This is more likely to happen with POPs containing the progestogen ‘desogestrel’. In addition, all POPs make the lining of the womb thinner so if sperm did fertilise an egg, the womb is less likely to be able to provide nourishment for this.
Where can I get the POP?
Can anyone use the pill?
The POP is very safe and only a few women are not able to take it.
Conditions which may mean you should not use the POP.
- Now or in the past you have had breast cancer
- You have certain types of liver disease
- You have certain types of rheumatic disease
- You are taking enzyme-inducing drugs
In addition, you should not continue with the POP if you develop ischaemic heart disease or a stroke whilst taking it. However, if you have a history of these conditions before starting the POP then you may still be prescribed it.
Many women who cannot take the combined oral contraceptive pill such as women who are over 35 and smoke are often able to use the POP because it does not contain oestrogen.
How old do I have to be to start the POP?
Once your periods have started you can take the POP.
What are the advantages of the POP?
Some of the good things about the POP are:
- There are no serious side effects
- It is useful if you cannot take oestrogens, like those found in the combined oral contraceptive pill
- You can use it if you are breast feeding
- It may help with pre-menstrual tension and heavy periods
What are the disadvantages of the POP?
- When you start any contraception which contains hormones, you may get spotty skin, sore breasts, put on some weight and have headaches. These symptoms normally stop within a few months. Stay on the POP and speak to your doctor or nurse if you have any concerns.
- It is impossible to predict what your bleeding pattern will be like on the POP. Some women continue with their normal periods while for some other women their periods may become lighter and less frequent, possibly even stopping all together. There are some women who have troublesome frequent bleeding on the POP. Every patient is different and your doctor or nurse will want you to talk to them if you have worries about your bleeding.
- The POP will not protect you from sexually transmitted infections and many women continue to use condoms whilst taking the POP.
- If you did get pregnant whilst taking the POP, there is a chance that the pregnancy may be growing outside of the womb. This is called an ectopic pregnancy.
Ectopic pregnancies usually develop in a Fallopian tube. They are not common but are dangerous. If you think you are or might be pregnant while on the POP it is important you see your doctor or nurse. If you have severe lower abdominal pain you should see a doctor urgently even if think you are not pregnant.
How do I take the POP?
If you start the pill on days 1 to 5 of your period then you will be protected from pregnancy immediately. Speak to a nurse or doctor for advice if you wish to start the pill at any other time.
Most pills come in foil strips of 28 tablets. It is important to take it at the same time every day and take one every day until the pack is finished. You start a new strip the next day with no breaks between the strips.
What should I do if I forget to take a POP on time?
If you take your pill more than 3 hours after your chosen time (or more than 12 hours for pills containing desogestrel) then your pill is less likely to work.
What to do if you are more than 3 hours late (12hours for pills containing desogestrel)
- Take the POP as soon as you remember. If you have missed more than one just take one
- Take your next POP at the usual time even if this means taking two POPs on the same day
- You are at risk of pregnancy until you have been taking your POPs again for 48 hours and you should use additional contraception such as condoms during this time.
- If you have had sex during the 48 hours since the pill was missed and you did not use a condom then you are at risk of pregnancy and should speak to a doctor, nurse or pharmacist about using emergency contraception .
What should I do if I have diarrhoea?
If you have severe diarrhoea continue taking your POP but use an extra method of contraception during the time you are unwell and until the diarrhoea has settled for 48 hours.
What should I do if I am sick?
If you vomit within 2 hours of taking a POP take another as soon as you fell well enough. If this is taken >3 hours (12 hours for desogestrel) later than normal then it may not be effective and you should abstain from sex or use condoms for the next 48 hours whilst continuing to take your POP as normal. If you continue to be sick, seek advice.
Effect of medicines on the POP
Commonly prescribed antibiotics do not affect the POP. However some drugs can reduce the effectiveness of the POP and increase the chance of getting pregnant. These include certain drugs used to treat HIV, TB and epilepsy as well as the herbal preparation ‘St. John’s Wort’. If you are taking any of these tablets you should speak to your doctor about the contraceptive options available to you. The emergency contraceptive pill Ella-One should be avoided if you are on hormonal contraception and if you are given Ella-One because you have missed pills you should not restart your pill for another 5 days. It will then take a further 48 hours until you have effective contraception so you should abstain or use condoms for this time
It is important that you are happy with the type of contraception you choose to use. Doctors and nurses are trained to work with you to find a method of contraception that suits you. Do not be afraid to discuss any concerns you may have.