Xanax (alprazolam) is a benzodiazepine used as an anti-anxiety medication prescribed to treat panic attacks and anxiety disorders. Treatment for patients with anxiety should be initiated with a dose of 0.25 to 0.5 mg Xanax given three times daily. Treatment of many panic disorders in patients has required the use of Xanax at doses greater than 4 mg daily. Anyone who needs this treatment can buy Xanax without a prescription. It has different variants available. The doses are Xanax 1mg, Xanax 2mg, and Xanax XR 3mg.