Emergency contraception

Also known as the morning after pill

If you have sexual intercourse and you do not use contraception, you may become pregnant. By using emergency contraception, you can reduce this risk. You may also need emergency contraception if you have missed taking contraceptive pills or a condom breaks.

What is the emergency contraceptive pill (ECP)?

The ECP is a high dose contraceptive pill containing a hormone called progesterone. It is thought the ECP stops pregnancy by preventing the release of an egg from the ovary. It may also cause changes in the lining of the uterus (womb) that discourages implantation of a fertilised egg. It is most effective if taken within 24 hours. 

The ECP can be taken up to three days following unprotected sexual intercourse (but is more effective when taken in first 24 hours) and can be used at any time during the menstrual cycle. 

The intra-uterine device (IUD) as emergency contraception

If the unprotected sex occurred more than three days ago it is advisable to talk to your healthcare professional as there may be other options (such as an intra-uterine device [IUD]).

Recent research has also shown that the ECP does not work well in women who weigh more than 70kg. If you fall into this category and require emergency contraception, talk to your doctor as soon as possible about having an IUD inserted. 

How do I take the ECP?

The ECP comes in tablet form; normally two tablets are required. Your healthcare provider will explain how to take the tablets. Follow their instructions carefully to ensure the ECP works properly. When taking the ECP:

  • Take the tablets as soon as possible. It helps to take them with food as some women feel sick after taking the ECP.
  • If you vomit within three hours of taking the pills, you should return to your healthcare provider as you may need to take them again.
  • If you are already using a regular method of contraception, such as the oral contraceptive pill, continue to take this at your regular time.

What happens next?

  • Some women may experience bleeding or spotting after taking the ECP and some may experience an early or later start to the next menstrual period.
  • It is important to have a pregnancy test 3 to 4 weeks after taking the ECP to ensure that you are not pregnant even if you have a period.
  • 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 professional about this as using ECP as a regular method of birth control is not recommended.

Sexually transmitted infections

Emergency contraception does not protect you against sexually transmitted infections. Arrange for a check up at your local sexual health clinic or with your family doctor two weeks after you have had unprotected sex.

Where can I get the ECP?

The funded ECP is known as Postinor (Dec 16) and this is available through:

Learn more

Emergency contraceptive pill New Zealand Family Planning (NZ), 2015
Postinor consumer information sheet Medsafe NZ 
Postinor NZ Formulary

Credits: Auckland Sexual Health Service and Health Navigator. Reviewed By: Health Navigator Editorial Team