Buy Xanax Online is the brand name for a medication called alprazolam, which belongs to a class of drugs known as benzodiazepines. This medicine is used to calm the brain. It is commonly prescribed to treat anxiety disorders, panic disorder, and sometimes insomnia. Xanax works by enhancing the effects of a neurotransmitter called gamma-aminobutyric acid (GABA), which helps to calm the brain.