Mifepristone(Mifeprex) is a synthetic steroid compound used as a pharmaceutical. It is used as abortifacient in the first two months of pregnancy, and in smaller doses it is used as an emergency contraceptive. [1]In the presence of progesterone, it acts as a competitive progesterone receptor antagonist (in the absence of progesterone, mifepristone acts as a partial agonist). It is a 19-nor steroid with a bulky p-(dimethylamino)phenyl substituent above the plane of the molecule at the 11β-position responsible for inducing or stabilizing an inactive receptor conformation and a hydrophobic 1-propynyl substituent below the plane of the molecule at the 17α-position that increases its progesterone receptor binding affinity.