HOW THE DRUGS WORK Mifepristone is taken first, swallowed by mouth. The drug dilates the cervix and blocks the effects of the hormone progesterone, which is needed to sustain a pregnancy. Misoprostol, a drug also used to treat stomach ulcers, is taken 24 to 48 hours later. The pill is designed to dissolve when placed between the gums and teeth or in the vagina. It causes the uterus to cramp and contract, causing bleeding and expelling pregnancy tissue. While the two-drug combination is slightly more effective, misoprostol is sometimes used alone for abortions. That practice is more common in countries...