Green Xanax bars are typically used for short-term treatment of acute anxiety, generalised anxiety disorders and panic disorders with or without agoraphobia. Green Xanax bars are green in color with 90 3' imprinted on them. It is similar to any other colored Xanax, and you can easily Buy Green Xanax Bars Online. It is the trade name for a drug called alprazolam. Alprazolam belongs to the family of benzodiazepines, and it works by enhancing the activities of several neurotransmitters in the brain.