Reviewed by Usama Ali, MPharm (GPhC: 2224726). Last reviewed: April 2026.
The mini pill is a daily contraceptive pill containing one hormone: progestogen. It is also called the progestogen-only pill, or POP. Unlike the combined pill, it does not contain oestrogen. That single difference is what makes it suitable for people who cannot or prefer not to take oestrogen, including those who are breastfeeding, have migraines with aura, smoke and are over 35, or have raised blood pressure.
Around 1.5 million women in the UK use the progestogen-only pill (FSRH, 2022). It is one of the most commonly prescribed forms of contraception through the NHS Pharmacy Contraception Service.
The mini pill prevents pregnancy in two or three ways, depending on the type you take.
All mini pills thicken the mucus at the entrance to the womb, making it harder for sperm to get through. They also thin the womb lining, which reduces the chance of a fertilised egg implanting.
Newer types of mini pill, specifically those containing desogestrel or drospirenone, also stop your ovaries from releasing an egg in most cycles. Traditional mini pills containing norethisterone or levonorgestrel do not reliably stop ovulation. This is an important distinction because it affects both effectiveness and the timing window you need to follow.
There are three types of mini pill available through the NHS Pharmacy Contraception Service, each with a different active ingredient and timing window.
| Type | Active ingredient | Late window | Stops ovulation? | Brands |
|---|---|---|---|---|
| Desogestrel | Desogestrel 75 micrograms | 12 hours | Yes, in most cycles | Cerelle, Cerazette, Feanolla, Zelleta |
| Drospirenone | Drospirenone 4 milligrams | 24 hours | Yes, in most cycles | Slynd |
| Traditional | Norethisterone 350mcg or levonorgestrel 30mcg | 3 hours | Not reliably | Noriday, Norgeston |
Desogestrel is the most commonly prescribed mini pill in the UK and is usually the first option offered. Slynd (drospirenone) is newer and has the widest timing window at 24 hours. It also has anti-androgenic properties, which can help with acne, and is taken as 24 active pills followed by 4 inactive pills per pack. Traditional mini pills are less commonly prescribed now because of the stricter 3-hour timing window.
"For most people starting the mini pill, we'd begin with desogestrel because it has the best balance of effectiveness and flexibility," says Usama Ali, MPharm (GPhC: 2224726), pharmacist at Contraception Direct. "If there's a reason that doesn't suit you, we'll talk through the alternatives."
For a closer look at the differences between desogestrel brands, read our guide on Cerelle vs Cerazette.
The mini pill is more than 99% effective with perfect use, meaning fewer than 1 in 100 people would become pregnant over a year. With typical use, where pills are sometimes taken late or missed, effectiveness drops to around 91% (FSRH, 2022).
That gap between perfect and typical use matters. The mini pill works best when you take it at the same time every day. Setting a daily alarm or using a pill reminder can help.
You take one pill at the same time each day. For most types (desogestrel, norethisterone, levonorgestrel), you take a pill every single day with no break between packs. Slynd works slightly differently: each pack has 24 active pills and 4 inactive pills, so you still take one daily but the last four contain no hormone.
The timing window depends on your pill type. If you take a desogestrel pill more than 12 hours late, it counts as missed. For traditional pills, the window is just 3 hours. Slynd gives you 24 hours. If you miss your window, use condoms for the next 48 hours and check the patient information leaflet for specific advice on what to do.
The mini pill is suitable for a wider range of people than the combined pill because it does not contain oestrogen. Through the NHS Pharmacy Contraception Service, it is available to people aged 16 to 54 (or 16 to 49 for Slynd).
It is a good option if you are breastfeeding, have a BMI over 35, smoke and are over 35, have high blood pressure, have a history of blood clots, or experience migraines with aura. All of these are reasons why the combined pill would not normally be prescribed, but the mini pill is still suitable.
Your pharmacist will check your medical history, current medications, and any conditions that might affect suitability before supplying the mini pill. Not everyone is suitable for every type, and some medications (such as certain epilepsy medicines, rifampicin, or St John's Wort) can reduce the pill's effectiveness.
The mini pill has several advantages. It does not contain oestrogen, so it avoids oestrogen-related side effects like headaches, nausea, and bloating. It does not increase the risk of blood clots, unlike the combined pill. It is safe from birth for breastfeeding mothers.
Many people find their periods become lighter or stop altogether, which can be a welcome change if you previously had heavy or painful periods. You can start the mini pill at most points in your menstrual cycle. And if you decide to stop, your natural fertility returns quickly, usually within days.
Like all hormonal contraception, the mini pill can cause side effects. Not everyone gets them, and for many people they are mild and settle within the first three months.
The most common side effects reported in clinical studies include irregular bleeding or spotting, changes to your usual period pattern, acne, breast tenderness, headaches, mood changes, and nausea. These are listed in the Cerelle summary of product characteristics and apply to all desogestrel mini pills.
Some people worry about weight gain on the mini pill. Current UK guidance does not show a clear link between the mini pill and significant weight gain, though some people do notice changes.
If side effects bother you or persist beyond three months, your pharmacist can discuss switching to a different type or formulation.
Bleeding pattern changes are one of the most common effects of the mini pill. Your periods may become lighter, less frequent, more irregular, or stop altogether. Some people get spotting between periods, particularly in the first few months.
These changes are not a sign that anything is wrong. They usually settle as your body adjusts to the hormone. For many people, lighter or absent periods are actually a benefit. If bleeding becomes heavy, persistent, or you have concerns, speak to your pharmacist or GP.
You can get the mini pill from your GP, a sexual health clinic, or a pharmacy through the NHS. All routes are free.
With Contraception Direct, you book a free phone consultation with a pharmacist who checks your suitability, discusses your options, and posts your pill in discreet packaging. Most deliveries arrive within 1 to 3 working days. The service covers both people starting the pill for the first time and those who need a repeat supply.
Not sure which type of pill suits you? Read our guide on which contraceptive pill is right for me or book a consultation and your pharmacist will talk it through with you.