Many pharmaceutical companies manufacture various alprazolam (Xanax) pills in various sizes, doses, shapes, and colors. People Buy White Xanax Bar Online to treat anxiety and panic disorder. White alprazolam pills are commonly branded Xanax, which is manufactured by the pharmaceutical company Pfizer. Usually, Xanax bars come in the form of a long rectangular "bar" with three grooves that allow them to be easily broken into up to four pieces for dosing. White Xanax bars are popular among drug users because they contain higher doses of alprazolam than many other Xanax pills. White Xanax bars typically contain 2 mg of alprazolam, which is a fairly high dose. The bars are frequently prescribed as an anxiety medication and are intended to be broken up into Xanax 0.25 or Xanax 0.5 mg doses.