Facebook Pixel

Morning-After Pill for Emergency Contraception: How Does It Work?

By Expert HERWriter
Rate This
Morning-After Pill Emergency Contraception: How Does It Work? Paul Hakimata/PhotoSpin

If a woman takes this pill just as she is about to ovulate (mid-cycle), ovulation will be delayed for 24-48 hours.

Understand, however, that sperm can live in healthy, fertile cervical mucus for three to five days. Ulipristal acetate is not as effective in women weighing over 195 lbs. This form is not over the counter and does require a prescription.

Common side effects for both can include nausea, vomiting, cycle changes or delay, and abdominal pain.

As neither pill is 100 percent effective in preventing pregnancy, there is always the chance that a woman will still become pregnant despite taking one of these pills. If she vomits within three hours of taking either pill, she will need to repeat the dose.

If a woman has any questions, she is encouraged to talk with either her health care provider or her pharmacist as soon as possible in order to have the greatest preventive effect, should she choose to take either pill.


Bastianelli, C., and Farris, M. Emergency Contraception. Expert Rev of Obstet Gynecol. 2011;6(5):569-576.

Linden, J., Mathews, J. (2014). Emergency Contraception After Rape.
Retrieved from http://www.medscape.com/viewarticle/824148_1

Reviewed July 17, 2014
by Michele Blacksberg RN
Edited by Jody Smith

Add a CommentComments

There are no comments yet. Be the first one and get the conversation started!

Enter the characters shown in the image.
By submitting this form, you agree to EmpowHER's terms of service and privacy policy

We value and respect our HERWriters' experiences, but everyone is different. Many of our writers are speaking from personal experience, and what's worked for them may not work for you. Their articles are not a substitute for medical advice, although we hope you can gain knowledge from their insight.

Emergency Contraception

Get Email Updates

Health Newsletter

Receive the latest and greatest in women's health and wellness from EmpowHER - for free!