Everything you need to know – Progesterone only pill (POP)

What is the progesterone only pill?

The progesterone only / mini pill (POP) is a small tablet you swallow daily that (unlike the combined pill) only contains one hormone – progesterone, and is often used by women that can’t tolerate oestrogen. This means fewer than 1 in 100 women who use the progestogen only pill as contraception will get pregnant in 1 year.

How effective is the progesterone only pill?

The progesterone only pill is 99% effective if taken as directed at the same time each day. But, if this mini pill is taken in a ‘typical’ way, i.e not strictly at the same time each day, its effectiveness drops to 92%.

How does the progesterone only pill work?

It prevents pregnancy by making the fluid in your cervix thicker (which makes it more difficult for sperm to enter the womb) and preventing the lining of your womb thickening enough for an embryo to grow in it. The progestogen-only pills with desogestrel in them (so all of them except Micronor, Noriday and Norgeston) can also stop ovulation.

How do I get started on the progesterone only pill?

Your doctor or nurse will do some tests to make sure that you can take the pill. They check your medical history, make sure that you’re not pregnant and take your blood pressure.

Most women can start the pill at any time in their period cycle. However unless you start the combined pill on the first day of your period, you won’t be protected from pregnancy straight away. Make sure you read the packet carefully and use condoms or other methods until you’re covered. There are special instructions for starting the pill if you have just had a baby, abortion or miscarriage.

There are normally 28 pills in a pack, and unlike the combined pill you don’t have a break between packs. It’s really important you reliably take the progestogen pill at the same time every day (more important than with the combined pill). There are two different types of progestogen only pill:

If it helps, keep your pill packet somewhere you use or look at every day (like your makeup bag) to remind you to take it, or set an alarm on your phone. You will normally be given a prescription for the pill for a couple of months, and will need to go back to your doctor for regular check-ups (e.g. blood pressure tests). If you want to read experiences from our Lowdown users, check out our progesterone only pill reviews.

How do I come off the progestogen only pill?

Stopping the pill is easy – you just stop taking it. As soon as you stop taking it, you’re no longer protected from pregnancy. If you have periods, you may prefer to wait until you reach the end of your current pill packet before stopping, so you can keep your cycle more regular. Check out our survey results to see how long it took most women’s cycles to return to their definition of ‘normal’, and read up about after effects they’ve experienced.

What if I miss taking a pill?

Missing or forgetting to take a pill has happened to the best of us. Check out the NHS guide which will help you with what to do, depending on how many you’ve missed and where you are in your menstrual cycle. If you have any doubt, then make sure you use alternative contraception such as a condom or don’t have sex until you’re protected.

Pros of the progestogen only pill

  • Doesn’t interrupt sex
  • Can use it when breastfeeding
  • Can use at any age – even if you smoke and are over 35
  • It’s useful if you can’t take the hormone oestrogen, which is the combined pill, contraceptive patch and vaginal ring.

Cons of the progestogen only pill

  • Vomiting and diarrhea will impact on how the pill is absorbed into your body. If you’re sick within two hours of taking the pill you’ll need to take another pill straight away and the next pill at the usual time. If you’re sick or have severe diarrhea for longer than this, check your pill packet for what to do next – and use condoms or abstain if you have any doubts.
  • Some medicines and antibiotics (like rifampicin and rifabutin, St John’s wort and anti-epilepsy drugs) change the way your body digests the pill.
  • With any combined type of hormonal contraception there is a slightly increased risk of developing blood clots in your veins and arteries.We are developing a full guide to the medical research on the serious and potentially life threatening side effects of contraceptives here.

How quickly does the mini pill protect me from pregnancy?

The mini pill can be started at any time during your cycle, but your protection from pregnancy varies depending on when you start it.

If you start at the beginning of your menstrual cycle (days 1 to 5 of your period) then it is effective immediately and you’ll be protected against pregnancy.

If you start on any other day of your menstrual cycle you won’t be protected immediately from pregnancy until you’ve taken the pill for two days (allowing the mucus in your cervix to thicken), so you will need to use additional contraception such as condoms. 

Will the progesterone only/mini pill affect my periods?

The progesterone-only pill can affect your periods by causing spotting between periods, or in some cases, your periods may stop altogether.

Progestogen only pill side effects

The progestogen only pill generally goes down quite well with users, and side effects are rare. However they could include:

  • Acne
  • Breast tenderness and breast enlargement
  • An increase or decrease in sex drive
  • Mood changes
  • Headaches and migraines
  • Nausea or vomiting
  • Small fluid-filled sacs (cysts) on your ovaries – they are usually harmless and disappear without treatment.

Who should use it?

  • Females over 35 that smoke
  • Females that can remember to take a pill regularly
  • Females that don’t want an internal contraception
  • Females that can’t take oestrogen based contraceptives

Who shouldn’t use it?

  • Females that think they might be pregnant
  • Females that don’t want their periods to change
  • Females that take other medicines that may affect the pill
  • Females that have unexplained bleeding in between periods and sex

What if I miss taking a pill?

Missing or forgetting to take a pill has happened to the best of us. Check out the NHS guide which will help you with what to do, depending on how many you’ve missed and where you are in your menstrual cycle. If you have any doubt, then make sure you use alternative contraception such as a condom or don’t have sex until you’re protected.

Where can you get the progestogen only pill?

In the UK, you should be able to get the progestogen only pill in most contraception clinics, sexual health clinics, some GP’s surgeries, some young people’s services.

This guide was brought to you by The Lowdown. We are the world’s first contraception review platform, providing real-life experiences from thousands of reviews collected from our community of men and women.

Why not leave us a review of your contraceptive experience? Whether you’ve got good things to say about the Mirena coil or had trouble with implant removal, we want to hear about it! Tell us about your experience and help people around the world find the right method for them.