Not Medical Advice: Aside from the color, green and white xanax bars have different manufacturers. Green xanax bar (such as pill with imprint S 90 3) and white xanax bars (like pills with imprints GG 249, G 372 2 and X ANA X 2) are all Alprazolam 2mg.
Manufacturers:
Green Xanax bar with S 90 3 imprint - Dava Pharmaceuticals Inc.
White Xanax bar with GG 249 imprint - Sandoz Pharmaceuticals Inc.
White Xanax bar with G 372 2 imprint - Greenstone Limited
White Xanax bar with X ANA X 2 imprint - Pfizer U.S. Pharmaceuticals Group
Xanax is the trade name of Alprazolam, a short-acting anxiolytic of the benzodiazepine class of psychoactive drugs.
Alprazolam is a short-acting anxiolytic of the benzodiazepine class of psychoactive drugs. It works by slowing down the movement of chemicals in the brain that may become unbalanced. It is associated with treatment of anxiety, depression, panic disorder, tinnitus and dysautonomia.
Find tips for Anxiety and Panic Disorder prevention at WebMD.