Progestogen-only pill
The progestogen-only pill (POP) is used to prevent pregnancy. It's made from only one hormone (progestogen). Every pill in the packet is the same. It is also known as the mini pill.
How does the progestogen-only pill work?
The progestogen-only pill works by:
- making the mucus (sticky fluid) at the entrance of the uterus thicker so sperm can't get through
- changing the lining of the uterus so a fertilised egg can't grow
- sometimes stopping the release of an egg by the ovary
How effective is the progestogen-only pill?
If taken correctly, it is 95-99% effective.
What are the good things about the progestogen-only pill?
The progestogen-only pill:
- can be safely used during breastfeeding as it does not interfere with the milk supply
- is less likely to cause nausea (feeling sick), weight gain and headaches than the combined Pill
- can be used by women who cannot take oestrogen, which is the other hormone found in the combined Pill
What are the side effects of the progestogen-only pill?
There might be changes to your periods such as:
- spotting
- irregular periods
- heavy periods
- absent periods
When does it start working?
It's immediately effective if started during the first 5 days after a period starts.
The POP is effective after 2 days (48 hours) if it is started at any other time in the menstrual cycle. Other contraceptive measures such as condoms should be used for these 2 days.
If changing from the Pill or another method of contraception, or after having a baby, discuss the best time for starting with your doctor.
Remember...
- It's important to take the progestogen-only pill at the same time every day for maximum effectiveness. Choose a time when you are most likely to remember taking it, and keep to it. If you are more than 3 hours late you may not be protected.
- Make daily pill taking a routine - you are less likely to forget it.
- You must take the progestogen-only pill continuously. There are no sugar pills to take, or a 7-day break as with some combined pills.
- If you have breakthrough bleeding (vaginal bleeding at times other than period bleeding) while taking the progestogen-only pill don't stop, continue the packet as usual. Consult a doctor if this persists.
- Some women may have less problems with some side effects if they change the type of progestogen-only pill they use.
What can stop the progestogen-only pill from working?
- Vomiting or diarrhoea
The POP may not work if vomiting occurs within 2-3 hours of taking a pill. Severe diarrhoea can also sometimes interfere with the POP. If you have vomiting or diarrhoea, keep taking the progestogen-only pill, but remember that you might not be protected. Use another method of contraception (e.g. a condom) until you have been able to take the progestogen-only pill for 48 hours. - A missed pill
If you forget to take a pill, or are more than 3 hours late, take it as soon as you remember and carry on with the next pill at the right time. Continue normal pill taking and use another method of contraception (e.g. a condom) for the next 48 hours. - Other medication
Some medication and non-prescribed medication (e.g. St John's Wort) may interfere with the progestogen-only pill. Discuss with your doctor any medications you are taking.
For women who are breastfeeding a baby...
The progestogen-only pill can be started shortly after the birth of your baby, often before leaving hospital. Research has shown that the amount of hormone that might pass through the breast milk is extremely low, and will not harm the baby.
Important information
If you feel you may be pregnant while taking the progestogen-only pill, see a doctor.
Am I at risk of sexually transmitted infections?
The progestogen-only pill does not protect you against sexually transmitted infections. Condoms are the only form of contraception that will help protect you from infection.
This information is available to download in leaflet format as Progestogen-only pill (PDF).