What Is the Mini Pill?

Reviewed by Usama Ali, MPharm (GPhC: 2224726). Last reviewed: October 2026.

What is the mini pill?

The mini pill is a daily contraceptive pill containing one hormone: progestogen. It is also called the progestogen-only pill, or POP. You may see it written as the progesterone-only pill, and in the US it is known as the progestin-only pill; these all mean the same thing. 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.

In the UK the mini pill is free from GP surgeries, sexual health clinics and pharmacies providing the NHS Pharmacy Contraception Service.

What is the difference between the mini pill and the combined pill?

The mini pill contains a progestogen only, while the combined pill also contains an oestrogen. That one difference means the mini pill is not thought to raise blood clot risk, needs no blood pressure check and is suitable while breastfeeding, while the combined pill gives a more predictable bleed and can be used to skip periods.

For a side-by-side guide to choosing between them, read combined pill vs mini pill. If you are not sure which suits you, a pharmacist can talk it through at a free consultation.

How does the mini pill work?

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.

What types of mini pill are available in the UK?

There are three types of mini pill available through the NHS Pharmacy Contraception Service, each with a different active ingredient and timing window.

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 a good 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.

How effective is the mini pill?

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. Our guide to how effective the contraceptive pill is covers what else can reduce your protection.

How do you take the mini pill?

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 (7 days for Slynd) and check the patient information leaflet for specific advice on what to do.

Who can take the mini pill?

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 from menarche up to age 54 (49 for Slynd). At Contraception Direct, we supply to patients aged 16 to 54 (16 to 49 for Slynd).

It is a good option if you are breastfeeding, have a BMI of 35 or above, smoke and are 35 or over, have high blood pressure, have had a blood clot, or get migraine with aura. Most of these are reasons the combined pill would not normally be prescribed (breastfeeding only in the first 6 weeks), 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.

What are the benefits of the mini pill?

The mini pill has several advantages. Because it contains no oestrogen, it can be used by many people who cannot take the combined pill. It is not thought to raise the risk of blood clots in the way the combined pill does. 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.

What are the side effects of the mini pill?

Mini pill side effects are usually mild, and most settle within 3 months. The most common is a change in bleeding pattern. For desogestrel, the most used mini pill, the patient leaflet also lists altered mood, reduced sex drive, headache, nausea, acne, breast pain and weight increase as common, affecting up to 1 in 10 people.

The table compares the common side effects listed in the patient information leaflets for Cerelle (desogestrel) and Slynd (drospirenone). Common means up to 1 in 10 people, and uncommon means up to 1 in 100.

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. Get medical help straight away if you have sudden or severe pain low in your abdomen, which can rarely be a sign of an ectopic pregnancy.

Does the mini pill stop your periods?

The mini pill can stop your periods, but it does not do so for everyone. FSRH guidance estimates that after about a year on desogestrel, 2 to 3 in 10 users have no bleeding, about 3 in 10 bleed infrequently and about 4 in 10 bleed at a normal frequency (FSRH, 2022). Irregular bleeding is common at first.

These changes are not a sign that anything is wrong, and absent periods are not harmful. For many people, lighter or absent periods are a benefit. If bleeding becomes heavy or persistent, or you have concerns, speak to your pharmacist or GP. Our guide on whether the pill stops your period compares all pill types.

How do you get the mini pill?

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.

This information is for general guidance only and does not replace advice from a clinician, pharmacist, or doctor. A clinician will review your consultation before any medication is supplied.