What is green Xanax Bars S903 2mg? Buy green Xanax bars S903 online in USA 2mg as a prescription medication that belongs to a medicine class called Benzodiazepines. The bars marked with R039 are blue, and Actavis Pharma Inc supplies rectangular pills with size 15 mm and weight 2 mg. Uses of green Xanax Bars 2mg Buy green Xanax Bars S903 2mg online in USA as a medication for the treatment of anxiety, panic disorder, and other medical conditions. Doctors most commonly prescribed these bars to treat anxiety in adults.