A Xanax 1 mg tablet contains 1 milligram of alprazolam. Alprazolam enhances the activity of gamma-aminobutyric acid (GABA), a neurotransmitter that reduces activity in parts of the brain involved in anxiety. Depending on the patient's condition and medical history, a healthcare professional may prescribe alprazolam at an appropriate strength and schedule. The strength of a tablet does not automatically indicate that it is appropriate for every patient. Age, medical conditions, other medications, previous exposure to benzodiazepines, and individual response can all influence prescribing decisions. Patients should never change their dose simply because a particular tablet strength is available online.