How it works
The mini pill, or progestogen-only pill, contains one hormone: progestogen. It thickens the mucus at the neck of the womb so sperm can't reach an egg, and the most commonly used types also stop your ovaries releasing an egg.
Taken correctly, it's over 99% effective. In everyday life, when pills sometimes get missed or taken late, it's around 91% effective.
Because it has no oestrogen, most people can take it, including people who are breastfeeding, who smoke and are 35 or over, who get migraines with aura, or who have a higher BMI.
Three types, three time windows
All mini pills are taken every day at about the same time. What differs is how late you can be before a pill counts as missed.
Desogestrel
The most commonly prescribed mini pill. It mainly works by stopping ovulation.
Cerazette, Cerelle, Zelleta, Desomono, Desorex and generic desogestrel.
12 hours
to take a late pill
Drospirenone
A newer mini pill with 24 active and 4 inactive pills. It mainly works by stopping ovulation.
Slynd.
24 hours
to take a late pill
Traditional
Older pills that mainly work by thickening cervical mucus, so timing matters most.
Noriday (norethisterone) and Norgeston (levonorgestrel).
3 hours
to take a late pill
Whichever you take, pick a time that fits your day and set a phone alarm.
How to take it
Take one pill every day, with no break between packs. Slynd has 4 inactive pills at the end of each pack, but you still go straight on to the next one.
Starting the mini pill
- Start on day 1 to 5 of your period and you're protected straight away.
- Start on any other day and use condoms for the first 2 days.
- Slynd is different: you're only protected straight away if you start on day 1 of your period. Otherwise use condoms for 7 days.
If you've recently had a baby, or you're switching from another method, the pharmacist will tell you exactly what applies to you.
Late pills and sickness
If you're later than your pill's window, take the late pill as soon as you remember, carry on as normal, and use condoms for the next 2 days (7 days for Slynd). If you've had sex since the pill was due, you may need emergency contraception.
Late with a pill? Check what to do
Our missed pill tool covers all three types of mini pill and tells you whether you need emergency contraception.
Use the missed pill toolIf you're sick or have diarrhoea
If you vomit soon after taking a pill, it may not have been absorbed. Take another as soon as you can if you're sick within 2 hours of a traditional mini pill, or within 3 to 4 hours of a desogestrel or Slynd pill. Severe diarrhoea can also stop it working, so use condoms and ask the pharmacist.
Bleeding and side effects
The most common side effect is a change to your bleeding. Your periods may stop, become lighter, irregular or more frequent. This isn't harmful, and it often settles, but if it bothers you, talk to us: a different pill may suit you better.
Benefits
- No oestrogen, so no increased risk of blood clots from oestrogen.
- Can be used while breastfeeding.
- Suitable if you smoke and are 35 or over.
- Periods may become lighter, or stop altogether.
- You can stop at any time, and your fertility returns quickly.
Possible side effects
- Irregular, frequent or absent bleeding.
- Spots, sore breasts or headaches, which often settle.
- Mood changes.
- It doesn't protect against sexually transmitted infections.
Who it isn't suitable for
Far fewer people are ruled out than with the combined pill. It may not be suitable if you:
- have or have had breast cancer
- have severe liver disease
- have had a stroke or serious heart disease
- have unexplained bleeding between periods or after sex
- have severe kidney disease (Slynd only)
Some medicines stop the mini pill working, including some medicines for epilepsy, HIV and tuberculosis, and St John's wort. Always tell the pharmacist what else you take.
Brands
Most desogestrel brands are interchangeable: Cerazette, Cerelle, Zelleta and generic desogestrel all contain the same hormone at the same dose. If you're already on a mini pill, find it in our list and book from there.
Based on NHS guidance and clinical guidelines from the College of Sexual and Reproductive Healthcare (CoSRH, formerly FSRH). Last updated September 2026. This page is general information, not a substitute for a consultation.