How does the progestogen-only pill (POP) work?
The progestogen-only pill, also known as the mini pill or POP, is a contraceptive pill you take daily. It thickens the mucus in the cervix so that sperm can't get to the egg to fertilise it and thins the lining of the womb making it difficult for a fertilised egg to implant there.
There are two types:
- 3-hour progestogen-only pill – must be taken within 3 hours of the same time every day.
- 12-hour progestogen-only pill – must be taken within 12 hours of the same time every day. This pill contains a progestogen called desogestrel. This type also works by stopping an egg from being released (ovulation).
Mini pill effectiveness
When used perfectly, the mini pill is over 99% effective, meaning fewer than 1 in 100 people who use it will become pregnant within a year. With typical use, which can mean someone forgot to take a pill or took it at the wrong time, it’s around 92% effective 1 which means 8 in 100 people who use it will become pregnant every year.
Taking the mini pill
The progestogen-only pill needs to be taken every day, without a break between packs.
If you can start your mini pill on day 1 (when your period starts) up to day 5 of your menstrual cycle, you will be protected from pregnancy straight away. If you start taking it on any other day of your cycle, you’ll need to use condoms or other contraception until you’ve taken it for 2 days.
Once you’ve finished a pack start a new one the next day.
Taking your pill at the same time every day is the most effective way to use the mini pill
Common mini pill brands
There are different brand names of mini pill, some are the traditional 3-hour pill and some are 12-hour mini pills:
3-hour - Norgeston, Noriday
12-hour (desogestrel) - Cerelle, Cerazette
Things to consider when taking the POP pill
- The POP pill doesn’t prevent you from getting sexually transmitted infections (STIs) so you may want to use condoms too.
- If you’re sick (vomit) within 2 hours of taking your pill it might not have been absorbed properly. Take another pill. If you continue to vomit you should use condoms until you’ve had 7 days without being sick.
- You will need to have a consultation before being prescribed the progestogen-only pill to ensure it’s suitable for you medically. This can be done by a GP, at a sexual health service or through the SHL.UK website.
- The progestogen-only pill might not be suitable for you if you’re taking other medicines, or have or have had some health conditions including breast cancer, liver or heart disease. Give as much detail about your health and any conditions you have/have had during your consultation.
- Some people get ovarian cysts while taking the mini pill. Other contraceptives may reduce ovarian cysts.
- It can be a good option if you’re unable to use contraceptives containing oestrogen.
- If it fails and you become pregnant there is a 1 in 10 chance the pregnancy could become ectopic
Potential side effects
Some people experience side effects when taking the progestogen-only pill, these include:
Spotty skin (acne), mood swings, breast tenderness and headaches - these usually settle within a few months.
Missing a pill
Less than 3 or 12 hours late
If you miss a 3-hour pill and are less than 3 hours late taking it you should take it immediately and take your next pill as usual. You’ll still be protected against pregnancy.
If you miss a 12-hour pill and are less than 12 hours late taking it you should take it immediately and take your next pill as usual. You’ll still be protected against pregnancy.
More than 3 or 12 hours late
Take a pill as soon as you remember – only take 1, even if you've missed more than 1 pill. Take your next pill at the usual time even if this means taking 2 pills on the same day. From then on, take the rest of your pills at your usual time.
Use additional contraception such as condoms for the next 2 days (48 hours) after you remember to take your missed pill, or don't have sex.
If you have unprotected sex from the time between your missed pill(s) and 2 days after you start taking it properly again, you may need emergency contraception.
Mini pill and periods
The mini pill can help with premenstrual symptoms and painful periods.
It can make your period lighter, more irregular, longer, more frequent or stop altogether. There’s no way to know which of these will happen for you so it helps if you’re comfortable with there being some change to your period.
Coming off the mini pill
If you are planning to come off the mini pill (POP) it’s better to finish your current pack first. Talk to your doctor or healthcare professional before coming off the mini pill so you can plan for your contraception needs after stopping.
Where can I get it free?
You can get the progestogen-only pill for free at NHS sexual health clinics, contraception clinics, GP surgeries and some young people’s services.
If you live in an eligible borough, you can take a consultation and order the progestogen-only pill from SHL.UK. It will be delivered to you by post or be made available for collection at a local Lloyds Pharmacy branch within an hour of your prescription being approved. Register or Login to see if the service is available to you.
Other contraception options
If the mini pill is not right for you, you might be interested in long-acting reversible contraception which is more effective and protects against pregnancy for longer, these include the intrauterine device, the intrauterine system, the contraceptive implant or the contraceptive injection.
There are also other contraceptives available like the pill that offer a bit more flexibility including the combined pill, the contraceptive patch and the vaginal contraceptive ring.
Reviewed by our clinical team: December 2020 (next review date: April 2022)
1. Source: NHS The progestogen-only pill - NHS (www.nhs.uk)