No, misoprostol cannot work without mifepristone. These two drugs are needed to perform specific functions throughout the abortion pill process. Mifeprex (mifepristone) blocks progesterone, a naturally produced hormone that prepares the lining of the uterus for a fertilized egg and maintains pregnancy. By blocking progesterone, Mifeprex causes the lining of the uterus to soften and break down, then bleeding and cramps begin. Mifeprex is also used in second trimester abortions. Cytotec (misoprostol) is a prostaglandin commonly used to protect the stomachs of people who need to take daily doses of anti-inflammatory medication. When used in the abortion pill, Cytotec causes the uterus to contract, which helps to expel the pregnancy.