Progestogen-only oral contraceptive pill (POP)

Also called the 'mini-pill’ or the progestogen-only contraceptive pill (POCP).

Easy-to-read medicine information about the progestogen-only pill (POP) – what it is, how to use it safely and possible side effects.

There are 2 types of oral contraception available in New Zealand. These are:

  • the combined oral contraceptive pill, known as ‘the pill’, which contains the hormones oestrogen and progestogen. Read more about the combined pill.
  • the progestogen-only pill (POP), sometimes known as 'the mini pill', which contains only progestogen.

This page covers information about the progestogen-only pill (POP)

On this page you will find information about:

Examples of the progestogen-only pill

Examples of the progestogen-only pill available in New Zealand include:

  • Cerazette® 
  • Microlut®
  • Noriday®

What is the progestogen-only pill?

The progestogen-only contraceptive pill (POP) is a form of contraception for women, to prevent pregnancy. It contains only progestogen, a hormone similar to one produced by your ovaries. It does not contain oestrogen.

  • POPs work mainly by thickening the mucus in your cervix so sperm can’t travel through it. 
  • Cerazette® also works by stopping you from producing a monthly egg and changes the lining of your womb so it is less likely to accept a fertilised egg.

What are the pros and cons of the progestogen-only pill?

Pros Cons

✔ It doesn’t interfere with sex.

✔ It can be used by women who are breastfeeding.

✔ There are very few side effects.



✘ It must be taken each day at the same time of the day whether you have sex on that day or not.

✘ It does not protect against sexually transmitted infections (STIs), so it’s important to use condoms when you have sex.

✘ It may cause irregular bleeding for a few months after starting. As long as you have not missed any pills, it will still be working as a contraceptive. If the bleeding continues, talk with your nurse or doctor. 

How well does the progestogen-only pill work?

The POP is one of the more reliable forms of contraception.

  • It is usually 92% effective, which means that it prevents pregnancy in 92 out of 100 women who use the POP each year. 
  • If used perfectly (no pills are missed), the POP is more than 99% effective in preventing pregnancy.
  • To ensure that the POP works best, you need to remember to take it every day, at about the same time every day, whether you have sex on that day or not.

How to take the progestogen-only pill

You must take the POP every day with no breaks. There are no inactive pills.

  • The usual dose of the POP is 1 tablet once a day. 
    • Most brands of the POP must be taken within 3 hours of the same time each day.
    • Cerazette® must be taken within 12 hours of the same time every day.
  • You can take the POP with or without food.
  • You can start taking the POP at any time in your menstrual cycle if you are certain you are not pregnant.
    • If you start on the first day of your period it starts working immediately. 
    • If you start at any other time during your menstrual cycle, it will take 48 hours to start working so to be safe you need to use additional contraception such as condoms, or not have sex for 48 hours (2 days) after starting.

What should I do if I miss my doses?

The advice for a missed pill depends on which brand you are taking.

Microlut and Noriday

A dose is considered 'missed' when more than 3 hours have passed since the regular dosing time.

  • If you forget to take the pill, take it as soon as you remember and take the next pill at the normal time (even if this means you take 2 pills within the same day). 
  • If you are more than 3 hours late in taking it then your protection immediately fails. Take your pill as soon as you remember and continue taking your pill each day, but you will also need to use extra contraception (such as condoms) or avoid sex for the next 2 days until the POP becomes effective again.
  • If you have unprotected sex within 48 hours of restarting the progestogen-only pill, contact your doctor, nurse, pharmacist or call Healthline 0800 611 116 for advice. You may need to use emergency contraception.

Cerazette

If you are taking Cerazette, a 'missed' dose is when more than 12 hours have passed since the regular dosing time.

  • If you forget to take your pill, take it as soon as you remember and take the next pill at the normal time (even if this means you take 2 pills within the same day). 
  • If you are more than 12 hours late in taking it then your protection immediately fails. Take your pill as soon as you remember and continue taking your pill each day, but you will also need to use extra contraception (such as condoms) or avoid sex for the next 7 days, until Cerazette becomes effective again.
  • If you have unprotected sex within 7 days of restarting Cerazette, contact your doctor, nurse, pharmacist or call Healthline 0800 611 116 for advice. You may need to use emergency contraception. 
If you are unsure about what to do if you have missed one or more pills, contact your doctor, nurse, pharmacist or call Healthline 0800 611 116 for advice.

What if I have diarrhoea (runny poo) and vomiting (being sick)?

Vomiting (being sick) and ongoing, diarrhoea (runny poo) can interfere with the effectiveness of the POP. The advice on what to do depends on the brand you are taking.

Microlut and Noriday

  • If you vomit within 2 hours of taking your pill, take another pill as soon as possible.
  • If you do not take a replacement pill within 3 hours of the normal time, or if you have ongoing vomiting or diarrhoea lasting more than 24 hours, use additional contraception (like condoms) or avoid having sex while you are unwell.
  • Continue using additional contraception until you have taken your regular doses for at least 2 consecutive days and continue your daily doses as normal. 
  • If you have had unprotected sex while you were unwell or within 48 hours of restarting the POP contact your doctor, nurse, pharmacist or call Healthline 0800 611 116 for advice. You may need to use emergency contraception.

Cerazette

  • If you vomit within 2 hours of taking your pill, take another pill as soon as possible.
  • If you do not take a replacement pill within 12 hours of the normal time, or if you have ongoing vomiting or diarrhoea lasting more than 24 hours, use additional contraception (like condoms) or avoid having sex while you are unwell.
  • Continue using additional contraception until you have taken your regular doses for at least 7 consecutive days and continue your daily doses as normal. 
  • If you have had unprotected sex while you were unwell or within 7 days of restarting Cerazette, contact your doctor, nurse, pharmacist or call Healthline 0800 611 116 for advice. You may need to use emergency contraception. 
If you are unsure about what to do if you have diarohhea and vomiting, contact your doctor, nurse, pharmacist or call Healthline 0800 611 116 for advice.

Who cannot take the progestogen-only pill?

This POP is especially recommended if you are breastfeeding or cannot use the combined pill for medical reasons such as having a history of:

  • blood clots
  • migraines
  • heavy smoking
  • very high blood pressure or heart disease
  • diabetes with complications
  • not being able to tolerate oestrogen.

The POP is not recommended if you:

  • have had breast cancer
  • are pregnant
  • are taking some medicines, over-the-counter medicines or herbal remedies — check with your doctor if you take these
  • have ischaemic heart disease or stroke or a past history of these conditions
  • have liver tumours or cirrhosis
  • have trouble remembering to take your pill each day.

There are different brands of POP available in New Zealand, each containing a different progestogen. Your doctor will discuss the best pill for you. If you experience side effects, or if you keep forgetting to take your pill, you may need to try another brand or another type of contraception before you find one that is suitable for you.

Side effects

Like all medicines, the POP can cause side effects, although these are very rare and not everyone gets them.

Side effects What should I do?
  • Breast discomfort
  • Headaches
  • Mood changes
  • Skin changes such as acne
  • Feeling sick (nausea) 
  • These are very uncommon and often go away with time.
  • If severe and ongoing, or if you are vomiting or have severe diarrhoea, tell your doctor or nurse.

Interactions

A few medicines, such as some antiepileptics, a few antibiotics and herbal supplements, may interact with the POP and lessen its effectiveness, so always check with your doctor or pharmacist before starting this and any new medicine.

Learn more

The following links provide further information about the POP:

Progestogen-only oral contraceptive pill Family Planning, NZ
Progesterone-only contraceptive pill Ministry of Health, NZ
 
More detailed information on specific brands of the POP:
Cerazette
Microlut
Noriday

References

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland and Dr Alice Miller, FRNZCGP, Wellington Last reviewed: 23 Mar 2021