While many people focus solely on RU 486, the so-called " French abortion pill," the RU 486 technique actually uses two powerful synthetic hormones with the generic names of mifepristone and misoprostol to chemically induce abortions in women five-to-nine weeks pregnant.

Mifepristone can be used alone or in combination with misoprostol to cause an abortion, within 49 days of the first day of a woman’s last menstrual period (LMP.)

• HOW IT WORKS: Mifepristone is given in early pregnancy to block the action of the natural hormone, progesterone.  This hormone prepares the uterine lining to receive a fertilized embryo. Mifepristone in combination with misoprostol (a prostaglandin that causes uterine cramping) produces many changes in a woman’s body.  These changes include an alteration of the uterine lining making it less hospitable for a fertilized embryo, uterine cramping, and softening of the cervix to allow expulsion of the embryo.[1] The FDA gave its final approval for the use of this drug in the US in September of this year.[2]  
  
  Three office visits are normally required; the first to confirm the pregnancy, obtain past medical history, counsel, sign consent forms, perform an ultrasound, and administer the first dose of mifepristone.  Two days later on a second visit, the patient will receive misoprostol. The complete abortion may occur with just the first medication; however, most women are given the misoprostol in 36-48 hours to make the process more efficient.[3]  Usually the patient will need to remain at the clinic for four hours after the second drug administration, as 61% of women will actually abort at this time. [4] If a third visit is required, it will be in 10-15 days, when termination of the pregnancy will be confirmed by ultrasound.[5]
  
  Counsel is an integral part of medical abortion procedures.  It must be ascertained whether the prospective candidate is suitable for the method and the provider needs to know the following.  Is she likely to return for the necessary visits?  Is she anxious to have this procedure over quickly?  Will she report complications promptly and does she have an adequate support system?

• FAILURE RATE: Mifepristone fails in about five of every 100 cases when used up to 49 days LMP.[6] Because this drug is most effective before seven weeks, gestational age of the pregnancy must be firmly established. [7] Some women who fail to abort with the first doses (see above) may need a second dose of the misoprostol, and the few who fail to abort after that are given a mini-suction abortion.[8] 

• SIDE EFFECTS: Bleeding, clotting, cramps, nausea, diarrhea and vomiting have all been reported.[9] The biggest danger however, is sending a woman home that might bleed so heavily she would need a blood transfusion.[10] Other unknown variables include the incidence of septic spontaneous abortion, and post-abortal infections.[11] Negative psychological trauma may occur after a medical abortion if the embryo is aborted late in the window of 7-49 days.  Besides seeing her aborted child a woman may be traumatized by being the active agent in causing the abortion. By ingesting the pills herself, she cannot think of the abortion as something that was done to her.  She was an active participant in the procedure and did not relinquish control to a surgeon.  No randomized study of clinical or psychological outcomes of mifepristone vs. surgical abortion has been done. [12]  

• EFFECTS ON THE DEVELOPING EMBRYO/BABY: Little is known about the effect of mifepristone on a developing embryo.[13] However, abnormalities were reported in several cases where women continued their pregnancies after taking mifepristone.[14]