The Morning-After Pill vs. The Abortion Pill

morning-after pill vs abortion pill
Morning-After Pill vs Abortion Pill. © 2015 Dawn Stacey

A common concern that confuses many people is whether or not the morning-after pill (Plan B One-Step) is the same thing as the abortion pill (RU486). This confusion stems from mistaken beliefs about emergency contraception. It is important to realize that these two medications serve very different purposes and work completely different from one another.

What is the Morning-After Pill?

The morning-after pill is a hormonal contraceptive.

When taken within 72 hours of unprotected sex or contraception failure, it can help to prevent pregnancy. The morning-after pill is sold over-the-counter to people of any age and consists of one pill that contains the progestin, levonorgestrel. It is sold under the following names: Plan B One-Step, Next Choice One Dose, My Way, Take Action, and AfterPill.

Although the exact way that the morning-after pill prevents pregnancy is not clear, how it works depends on where you are in your menstrual cycle. If you are already pregnant, and you take the morning-after pill, it will not harm your pregnancy and does not cause an abortion.

What is the Abortion Pill?

The abortion pill (also referred to as M&M, Mifeprex, RU486, and mifepristone) is used an early medical abortion option. It results in a termination of a pregnancy and is only used after pregnancy is established (and no more than 49 days since a woman’s last menstrual period).

The abortion pill was first used safely in Europe and was FDA-approved to be used in the U.S. in September 2000. The abortion pill usually consists of two medications -- one to cause the uterine lining to shed (so a fertilized egg cannot remain attached), and one that causes the uterus to contract.

When used together, medical abortion is 95-97% effective in terminating a pregnancy.

So Why Are People Confused About the Morning-After Pill and the Abortion Pill?

Much of this confusion stems from beliefs about how the morning-after pill works. Plan B One-Step (as well as the other morning-after pill brands) lowers you chances of becoming pregnant by preventing or delaying ovulation and/or by interfering with sperm movement (causing it less likely that sperm will fertilize an egg). The real misunderstanding has to do with whether or not the morning-after pill prevents a fertilized egg from implantation. Although research shows that Plan B One-Step does not interfere with implantation, the FDA labeling on the morning-after pill says that it “may inhibit implantation.”

Why Does the FDA labeling for the Morning-After Pill Say One Thing When the Research Says Something Else?

It seems that the research the FDA used during the approval process of the morning-after pill mainly focused on the safety and effectiveness of the main ingredient (the progestin levonorgestrel.

Because this research did not examine exactly how the morning-after pill worked, the FDA chose to include that it could affect implantation on the product’s labeling (mainly because the thinking was that because birth control pills may work by changing the lining of the uterus, the morning-after pill does, too). That being said, the FDA now admits that the existing data and research on the morning-after pill indicates that this product does not interfere with implantation.

What Are People Debating About?

Medical experts including the FDA, The American College of Obstetricians and Gynecologists, and The National Institutes of Health agree that the establishment of a pregnancy takes several days and is not completed until a fertilized egg has implanted in the lining of the woman's uterus.

      -->So -- medically, you are considered to be pregnant only after implantation has occurred.

But, many individuals (including pro-life and religious organizations) continue to hold unto to the mistaken belief that the morning-after pill prevents implantation of a fertilized egg. They are quick to debate its use and incorrectly label this type of contraceptive as an abortifacient (something that causes pregnancy to end prematurely and causes an abortion). This inaccurate thinking that the morning-after pill causes abortion has created a barrier to the access and use of the morning-after pill. Women with certain religious backgrounds may not even ask about it because they have been told that it causes abortions. There are even instances where hospital emergency rooms refuse to provide the morning-after pill to women who have been raped.

The Morning-After Pill vs. The Abortion Pill -- Bottom Line:

Advocates of the morning-after pill remain firm about educating people that this medication is not an agent of abortion. Medical authorities define an abortion as the disruption of an implanted fertilized egg. Federal policy, as well, agrees with the medical community, and defines drugs and devices that act before implantation as preventions to pregnancy rather than agents that terminate pregnancy.

The accurate way to understand the difference between these two medications:

  • The abortion pill is method of abortion. It is FDA-approved to terminate a pregnancy in women who are up to 7 weeks pregnant.
  • The morning-after pill is a type of emergency contraception. It is FDA-approved to prevent pregnancy and will not harm an existing pregnancy. Medically, a woman is NOT considered to be pregnant if she has a fertilized egg that has not yet implanted in her uterus. This means that it is impossible for the morning-after pill to terminate a pregnancy since, medically, the pregnancy doesn’t exist.


Marions L, Hultenby K, Lindell I, Sun X, Stabi B, & Gemzell-Danielsson K. "Emergency contraception with mifepristone and levonorgestrel: Mechanism of action." Obstetrics and Gynecology 2002; 100(1): 65-71. Accessed via private subscription.

Prine L. "Emergency contraception: Myths and facts." Obstet Gynecol Clin N Am.. 2007; 34:127–136. Accessed via private subscription.

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