Progestogen-only oral contraceptive pill

Commonly known as 'the mini-pill'

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

Type of medicine Also called
  • Contraceptive pill (prevents pregnancy)
  • Progesterone
  • Also known as 'the mini-pill’, or the progestogen-only pill (POP) or progestogen-only contraceptive pill (POCP)
  • Cerazette®
  • Microlut®
  • Noriday®

There are two 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
  • the progestogen-only pill, known as 'the mini-pill', which contains only progestogen.

This page covers information about the mini-pill. Click to read more about the pill.

What is the mini-pill?

The mini-pill is a form of contraception for women, to prevent pregnancy. It contains only one hormone, progesterone. It does not contain oestrogen.


  • Easy to use – one tablet at the same time each day.
  • It doesn’t interfere with sexual intercourse.
  • Can be taken by women who are breastfeeding.
  • There are very few side effects.


  • If you are not good at remembering to taking a pill each day, then this is not right for you.
  • The mini-pill must be taken each day at the same time of the day whether you have sex on that day or not.
  • Some women can have irregular bleeding for a few months after starting the mini-pill. So 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 does the mini-pill work?

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

Who can take the mini-pill?

This mini-pill is especially recommended for women who are breastfeeding and women who 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 mini-pill is not recommended for women who:

  • have had breast cancer
  • are pregnant
  • are taking some medications, over-the-counter preparations or herbal remedies — check with your doctor if you take regular medicine.

There are a few different brands of mini-pill available in New Zealand, each containing a different progesterone. Your doctor will discuss the best pill for you. If you experience side effects, you may need to try another brand, before you find one that is suitable for you.

How well does the mini-pill work?

The mini-pill is one of the more reliable forms of contraception.

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

How to take the mini-pill

You must take the mini-pill every day with no breaks and no inactive pills.

  • The usual dose of the mini-pill is one tablet once a day. 
    • Some mini-pills 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 mini-pill with or without food.
  • You can start taking the mini-pill at any time in your menstrual cycle.
    • If you start on the first day of your period it is effective immediately.
    • If you start at any other time during the menstrual cycle, the mucus effect will provide protection 48 hours later.
    • To be completely safe you may want to use other contraception, such as condoms, or not have sex for 7 days after starting.

Missed pill

If you forget to take a mini-pill, take it as soon as you remember.

  • If you are more than 3 hours late in taking it (or more than 12 hours with Cerazette®) then your protection immediately fails.
  • Continue taking your pill each day, but you will need to use extra contraception (such as condoms) for 2 days until the mini-pill becomes effective again.

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.  

Diarrhoea and vomiting

Vomiting and ongoing, severe diarrhoea can interfere with the effectiveness of the mini-pill.

  • If you vomit within two hours of taking your mini pill or have severe diarrhoea, the pill will not be absorbed, so take another pill as soon as possible.
  • Carry on taking the mini-pill as usual, but use other forms of contraception (such as condoms) for the duration of the illness plus for a further two days after the vomiting or diarrhoea has stopped.

If you are unsure about what to do if you have vomiting and diarrhoea, contact your doctor, nurse, pharmacist or call HealthLine 0800 611 116 for advice.

Possible side effects

Like all medicines, the mini-pill 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 persistent, or if you are vomiting or have severe diarrhoea, tell your doctor or nurse


A few medications and herbal supplements may interact with the mini-pill and lessen its effectiveness, so always check with your doctor or pharmacist before starting any new medication.

Learn more

The following links provide further information about the mini pill:

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

Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 22 Jan 2019