The Progestogen-Only Pill: What to Know
The progestogen-only pill, often called the mini pill or POP, is a daily tablet that contains just one hormone. It is an excellent option for women who cannot take oestrogen, such as those who smoke, are over 35 or have migraines with aura. Because it gets less attention than the combined pill, the timing rules and quirks of the mini pill often come as a surprise. This guide sets out what you need to know before you start.
What the mini pill is
The progestogen-only pill comes in a few strengths. Older types, such as norethisterone, work mainly by thickening cervical mucus and must be taken at almost exactly the same time each day. Newer types containing desogestrel also stop ovulation in most cycles and offer a slightly wider window if a dose is late. Both are taken every day with no break, which means your period may become lighter, irregular or stop altogether.
How it works
The daily progestogen keeps the mucus at the neck of the womb thick, making it hard for sperm to reach an egg, and keeps the womb lining thin. In desogestrel formulations, it usually also stops the release of an egg. Unlike the combined pill, there are no hormone-free days, so you do not have a withdrawal bleed, and the protection does not pause at any point in the month.
Timing and missed pills
Timing is the most important part of taking the mini pill. Older mini pills have a three-hour window, meaning if you are more than three hours late you are not protected. Desogestrel pills allow 12 hours. If you are late, use condoms and seek advice on whether you need emergency contraception. A daily alarm, or keeping the pack with something you never forget, is the simplest way to stay on track. If you are sick within two to three hours of taking a pill, treat it as missed.
Side effects and what to expect
Most women notice little at all, but common early effects include irregular bleeding, breast tenderness, headaches, mood changes and spots, which usually settle within three months. The progestogen-only pill does not affect the risk of blood clots the way the combined pill does, which is why it is a popular choice for older women and smokers. If bleeding patterns are bothering you or your periods have not settled, check with a pharmacist or GP.
| Consideration | Progestogen-only pill | Combined pill |
|---|---|---|
| Hormones | Progestogen only | Oestrogen and progestogen |
| Timing window | 3 or 12 hours depending on type | Less strict, up to 24 hours |
| Pack break | None, taken daily | Usually 7 days each month |
| Suitable if you smoke over 35 | Usually yes | Usually no |
| Periods | Often lighter or absent | Regular withdrawal bleed |
Who the mini pill suits
The progestogen-only pill is a sensible option if you want a daily method but cannot use oestrogen, if you are breastfeeding, or if you want to avoid the small blood clot risk of the combined pill. It is not the best choice for everyone, and some women prefer the reliability of an implant, injection or coil so they never have to remember a tablet.
Starting and stopping
You can start the mini pill on any day of your cycle, and you are protected immediately if you start on days 1 to 5 of your period. Otherwise you need seven days of correct use before you are protected. When you stop, your normal cycle usually returns quickly, and you may ovulate within a few days, so use a barrier method if you are not ready for pregnancy. The pill is prescription-only in the UK, supplied after a consultation with a GP or registered UK online pharmacy.
If a daily tablet fits your routine and you cannot or would rather not use oestrogen, the mini pill is a reliable, low-risk choice worth discussing with a professional.