Emergency contraception

Also known as the morning after pill or the copper IUD

Emergency contraception can be used after unprotected sex if you don’t want to get pregnant. Emergency contraception does not protect you against sexually transmitted infections (STIs).

What is emergency contraception?

Emergency contraception can be used after unprotected sex if you don’t want to get pregnant. Unprotected sex means either:

  • you haven't used protection, such as a condom or a regular contraceptive pill (‘the pill’)
  • your normal contraception/ārai hapū fails, eg, a condom splits
  • you have missed one or more of your regular contraceptive pills (the exact number of missed pills depends on which type of pill you are taking and whether you usually take them every day or have a break each month)
  • you usually take regular contraceptive pills (‘the pill’) but have been vomiting or had diarrhoea 
  • you have missed your contraceptive injection
  • you have been forced to have sex without contraception.

Choosing the right emergency contraception.

There are 2 main types of emergency contraception:

  • copper intra-uterine device (IUD) – a small object that is placed inside your uterus (womb)
  • emergency contraceptive pill (ECP).

When you talk to a nurse, doctor or pharmacist about getting emergency contraception, they will ask you a few important questions. These may seem like personal questions, but they want to make sure you get the emergency contraception that works best for you. The most effective emergency contraceptive is the IUD, but the ECP can be effective and convenient in many situations.

Factors to consider  How they may affect the choice of emergency contraception
How long ago you had unprotected sex
  • A copper IUD can be inserted up to 5 days after unprotected sex, or within 5 days of your earliest expected date of ovulation. To work this out, the nurse or pharmacist might ask when your last period was and how long your cycles are. 
  • The ECP can be taken up to 72 hours (3 days) after unprotected sex, but is most effective when taken in the first 24 hours – it is less effective as time passes.  
Your weight
  • The copper IUD is recommended for women who weigh over 70 kg.
  • The ECP may not be effective for women weighing over 70 kg. You should consider using the IUD or, in some cases, taking double the dose of the ECP. 
  • Talk to your doctor or pharmacist before taking a double dose – it is an unapproved dose and the effectiveness of this option has not been fully studied.
If you are taking other medicines
  • Tell your doctor or pharmacist if you are taking other medicines.
  • Some medicines such as anti-epilepsy medicines, some antiviral medicines and other medicines, can affect the ECP (these include carbamazepine, phenytoin, oxcarbazepine, phenobarbital, primidone, rufinamide, topiramate, rifampicin and ritonivir). 
  • Herbal medicines such as St John’s Wort can also affect the ECP. 
  • The copper IUD is the recommended emergency contraception if you are taking these medicines.
  • Alternatively the dose of the ECP will need to be doubled, but this is an unapproved dose and the effectiveness of this option has not been fully studied.
Where and how can I get the emergency contraception  
  • The copper IUD must be inserted by a trained health professional. 
  • You can get the ECP from a doctor, nurse or pharmacy. You can have a supply at home just in case you need it, but the ECP should not be used as ongoing contraception.
Ongoing contraception protection
  • The IUD can be removed when your next period occurs or it can be left in place for ongoing contraception for several years.
  • An ECP does not give you any ongoing protection against pregnancy. It is only for unprotected intercourse in the past 72 hours. 
  • You may be more likely to get pregnant the week after taking an ECP unless you use a contraceptive.
  • Talk to your health professional if you need regular contraception.

Copper IUD

An IUD is a small object that is placed inside your uterus (womb). A copper IUD can be inserted up to 5 days after unprotected sex, or within 5 days of your earliest expected date of ovulation. To work this out, the nurse or pharmacist might ask when your last period was and how long your cycles are.

The IUD 
works by preventing implantation in your uterus and can be removed when your next period occurs or it can be left in place for ongoing contraception.

The copper IUD is recommended as the most effective form of emergency contraception for women who weigh over 70 kg. It is also preferred if the unprotected sex occurred more than 3 days ago. A healthcare professional needs to insert the IUD, which can be uncomfortable, but while it is in place, it can be used for ongoing contraception.

Emergency contraceptive pill

The ECP is a high dose contraceptive pill with a hormone called progesterone. The ECP works mainly by delaying ovulation, but there is a risk of pregnancy if you have unprotected sex later in your cycle. It doesn’t work once the egg has been fertilised and it doesn’t harm you or a developing embryo. 

The ECP can be taken up to 72 hours (3 days) after unprotected sex, but is most effective when taken in first 24 hours – it is less effective as time passes. The ECP should prevent:  

  • 95% of expected pregnancies when taken within 24 hours of sex
  • 85% of pregnancies if taken within 25–48 hours
  • 58% of pregnancies if taken within 49–72 hours.

The ECP  may not be as effective for women weighing over 70 kg. You should consider using the IUD or taking double the dose (take 2 ECPs together). This is an unapproved dose, and the effectiveness has not been fully studied.

Tell your doctor or pharmacist about any other medication you are taking. Some other medicines affect the way the ECP works, so you may need extra doses or a copper IUD. If you vomit within 3 hours of taking the ECP you’ll need to take another dose. 

How do I take the ECP?

The ECP is a tablet. If you weigh less than 70 kg, take 1 tablet as soon as you can within 3 days (72 hours) of unprotected sex. Your healthcare provider will explain how to take the tablet. Follow their instructions carefully to ensure the ECP works properly. Do the following when taking the ECP:

  • Take it as soon as possible.
  • It helps to take it with food as some women feel sick after taking the ECP.
  • If you vomit within 3 hours, go back to your healthcare provider as you may need to take it again.
  • If you are already using regular contraception, such as the oral contraceptive pill ('the pill'), keep taking this at your regular time.

What happens next?

  • Some women may notice bleeding or spotting after taking the ECP and some may have an early or later start to your next menstrual period.
  • Even if you have a period, it's important to have a pregnancy test 3–4 weeks after taking the ECP to make sure you are not pregnant.
  • There is no evidence that the ECP will affect the unborn baby if you do become pregnant.

Future contraception

The ECP does not give you any ongoing protection against pregnancy. It is important to use condoms or another form of contraception for ongoing protection against pregnancy. You can talk to your health provider about this, as using ECP as a regular method of birth control is not recommended.

Where can I get the ECP?

The currently funded ECP is known as Postinor and this is available through:

Learn more

Emergency contraceptive pill Family Planning, NZ
Postinor consumer information sheet Medsafe, NZ 
Postinor NZ Formulary

Credits: Health Navigator Editorial Team. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 15 May 2020