Green Xanax bars are one of the various forms of Alprazolam sold under the brand name Xanax. It is a prescription medicine like other drugs in the benzodiazepine family of drugs. http://www.concealpharmacy.com/product/green-xanax-bars-2mg/ They are rectangular tablets imprinted as S 903; contain two mg of active Alprazolam. In the United States, Dava pharmaceutical company is manufacturing this anti-anxiety medicine. Green Xanax bars are mainly prescribed to treat short-term anxiety disorder, generalized anxiety disorder, depression, and panic attacks.