Progestogen-only oral contraceptive 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 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
  • the progestogen-only pill, known as 'the mini pill', which contains only progestogen.

This page covers information about the mini pill. 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.

Advantages

  • It's easy to use – take 1 tablet at the same time each day.
  • It doesn’t interfere with sexual intercourse.
  • It can be taken by women who are breastfeeding.
  • There are very few side effects.

Disadvantages

  • 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. 
  • It doesn't protect against sexually transmitted infections (STIs), so it is still important to use condoms during sexual intercourse. 

How does the mini pill work?

Some mini pills 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.

Who can take the mini pill?

This mini pill 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 mini pill 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.

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 it prevents pregnancy in 92 out of 100 women who use the mini-pill each year.
  • If used perfectly (no pills are missed), the mini pill is more than 99% effective in preventing pregnancy.
  • To ensure that the mini pill works best, you need 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. There are no inactive pills.

  • The usual dose of the mini pill is 1 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

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 sexual intercourse for the next 2 days until the mini pill becomes effective again.
  • If you have unprotected intercourse 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 sexual intercourse for the next 7 days, until the mini pill becomes effective again.
  • If you have unprotected intercourse 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.

Diarrhoea and vomiting

Vomiting (being sick) and ongoing, severe diarrhoea (runny poo) can interfere with the effectiveness of the mini pill. 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 very severe diarrhoea lasting more than 24 hours, use additional contraception (like condoms) 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 unprotected intercourse while you were unwell or 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 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 very severe diarrhoea lasting more than 24 hours, use additional contraception (like condoms) 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 unprotected intercourse 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.

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 ongoing, or if you are vomiting or have severe diarrhoea, tell your doctor or nurse.

Interactions

A few medicines, such as some antiepileptics, antibiotics and herbal supplements, may interact with the mini pill 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 mini pill:

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

References

  1. Progestogen-only oral contraceptives New Zealand Formulary
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 22 Jan 2019