How Do Abortion Pills Work?

Mifepristone blocks progesterone which is a natural hormone produced in the body during pregnancy and is responsible for keeping the pregnancy attached to the uterine wall. Without progesterone, the pregnancy will stop growing. Mifepristone makes the uterus sensitive to contractions and softens the cervix in preparation for the abortion. 

Mifepristone at 200mg is used to end a pregnancy. At lower doses (around 25mg) it can be used as a contraceptive or the morning-after pill. It will effectively prevent pregnancy and could be called the “pre-sex pill” because it could be effective for up to one week after taking. It is being used for this purpose mainly in Eastern Europe and China. Currently, studies are being done to innovate European, African, and North/ South American countries by offering mifepristone in smaller doses and making this available. 


Misoprostol is needed to start uterine cramping and remove the pregnancy tissue. The uterus will naturally start the process of miscarriage when a pregnancy stops growing, but this could take weeks.  To prevent potential infection, misoprostol is used to start the uterine cramping and remove the pregnancy before the infection can start. 

To pass the pregnancy, your cervix will dilate. Misoprostol helps with this dilation process by softening the cervix, so it can more easily open. You will feel pain and cramping during this part of the process, as the muscle opens. The more a person can relax during this process, the less pain they will feel.

Before taking misoprostol, it is advisable to take ibuprofen. Do NOT take aspirin, as it thins the blood and could make you bleed more. 

Usually, an abortion can be completed with one dose of mifepristone 200mg, followed 24-48 hours later with one dose of misoprostol 800mcg (4 pills, 200 mcg each). However, sometimes not all products of the pregnancy are expelled. In this case, there is a risk of infection or hemorrhaging. 

In some cases, your doctor may recommend a subsequent dose of misoprostol to remove the remaining tissue. In other cases, they will perform a surgical abortion to remove the remaining tissue.

The 2018 World Health Organization Guidelines for Medical Abortion recommend subsequent doses of misoprostol after taking mifepristone in order to complete a medical abortion. This is NOT always necessary, but depending on how your body expels the pregnancy, it may be necessary to have a couple of extra doses of misoprostol on hand.