Information about the Morning After Pill

What is the Morning After Pill?

The Morning After Pill, also called Emergency Contraception, is a form of birth control that is taken up to 72 hours after sexual intercourse.  In New Zealand the brand name is Postinor.

Will the Morning After Pill protect me from STDs?

No, the Morning After Pill will not protect you from contracting a sexually transmitted disease (STD) or infection (STI).

Will the Morning After Pill work if I am overweight?

The Morning After Pill has been found to be less effective in women who are even slightly overweight, and completely ineffective in obese women. [1]

Can I become pregnant after taking the Morning After Pill?

Yes.  No form of birth control is completely effective.  The Morning After Pill is less effective than most other forms of birth control.  Estimates of its effectiveness in preventing pregnancy range from 95% to as little as 58%.  [2]

What are my chances of becoming pregnant?

There are only about six days a month around the time of ovulation where there is a chance you could get pregnant.  There is no significant chance of getting pregnant outside that time.

The Morning After Pill can delay ovulation, so it is possible to get pregnant after sexual intercourse later in the month, even after taking the Morning After Pill.

If you are worried that you may be pregnant you can ring 0800 367 5433 to talk to someone about your concerns.

Are there side effects and risks?

All drugs have side effects and risks.  For the Morning After Pill, the common side effects are nausea, vomiting, diarrhoea, headache, fatigue and bleeding not related to a normal period.

Does the Morning After Pill cause abortions?

One of the stated modes of action is to prevent the implantation of an embryo (newly formed human being) into the uterus (womb).  No one knows how often this happens.  There are only about six days a month that a woman can get pregnant [3] and the Morning After Pill is only effective at stopping ovulation on the first three of these days.  It is unable to stop ovulation on the last two of these six days [4], when the chances of conceiving are highest.  On these days it relies on other means, including preventing implantation and disrupting embryo transport.  Both these mechanisms can lead to the death of embryos.

Those that say the Morning After Pill does not cause early abortions believe that pregnancy only begins at implantation, when the embryo settles into the lining of the womb.  However, science tells us that at the moment of fertilisation (when the sperm meets the egg) defining features such as gender, eye colour and hair colour, among other things, are all determined. [5]

If you are wondering if you are pregnant and are not sure what to do, please phone 0800 367 5433, text 027 448 80 70 or send a message via our Contact page.
Our friendly team offer free and confidential pregnancy tests and can talk through your situation and discuss your options.

Do other forms of emergency ‘contraception’ cause abortions?

The only other method currently available in New Zealand is the Copper IUD.  It would be impossible for the Copper IUD to have its claimed effectiveness as an emergency contraceptive without it causing the deaths of embryos (newly formed human beings). IUDs can be very painful to have inserted or removed, particularly for women who have not had children.

More Information and Downloads:

For more information please see the footnotes below.  You can also download the following documents:

Medsafe Datasheet for Postinor-1
This Datasheet includes information on how the Morning After Pill works, warnings and precautions, contraindications and adverse effects.  Other information is also included.

What you need to know about the Morning After Pill
This mini pamphlet, perfect for your purse or pocket, contains most of the information on the Morning After Pill found on this page.

Information about the Morning After Pill Fact Sheet
A printable version of this page for you to download.


The information presented on this website is intended for general education purposes only and should not be relied upon as a substitute for professional and/or medical advice.


The following are footnotes to the text above.  They also serve as reference material for the pamphlet What you need to know about the Morning After Pill produced by Family Life International NZ.

1. Glasier, Anna, Sharon T Cameron, Diana Blithe, Bruno Scherrer, Henri Mathe, Delphine Levy, Erin Gainer, and Andre Ulmann.  “Can We Identify Women at Risk of Pregnancy despite using Emergency Contraception? Data from Randomized Trials of Ulipristal Acetate and Levonorgestrel.” Contraception 84, no. 4 (October 2011): 363-367. (Accessed 17 June 2014).

Associated Press. “Morning-after Pill Doesn’t Work for Overweight Women, Says French Maker.” The Guardian, November 26, 2013, sec. Society. (Accessed 17 June 2014).

2. Harrison-Woolrych, Mira. “Progestogen-Only Emergency Contraception and Ectopic Pregnancy.” Medsafe, October 2002. (Accessed 17 June 2014)

Trussell, James, Elizabeth G Raymond, and Kelly Cleland. “Emergency Contraception: A Last Chance to Prevent Unintended Pregnancy,” December 2013. (Accessed 17 June 2014).

3. Wilcox, Allen J., Clarice R. Weinberg, and Donna D. Baird. “Timing of Sexual Intercourse in Relation to Ovulation — Effects on the Probability of Conception, Survival of the Pregnancy, and Sex of the Baby.” New England Journal of Medicine 333, no. 23 (1995): 1517–1521. (Accessed 17 June 2014).

4. Gemzell-Danielsson, Kristina, Cecilia Berger, and P.G.L Lalitkumar. “Emergency Contraception — Mechanisms of Action.” Contraception 87, no.3 (March 2013): 300–308. (Accessed 17 June 2014).

5. Kliegman: Nelson Textbook of Pediatrics 18th Edition, 2007 Sauders, an Imprint of Elsevier.  Chap 79 The Human Genome; (Accessed July 16, 2010).