Xanax XR is an extended-release formulation of alprazolam. Alprazolam belongs to a group of medicines called benzodiazepines, which influence activity involving gamma-aminobutyric acid (GABA) in the central nervous system. This produces a calming effect that can reduce excessive anxiety and related symptoms.​ It is important to understand that Xanax 3 mg XR (alprazolam extended-release) is a prescription benzodiazepine used for certain anxiety and panic disorders. Searches such as “buy Xanax 3 mg XR online” may lead people to websites offering medication without appropriate medical oversight, but purchasing controlled prescription medicines from unverified sources can create serious safety and legal concerns.