How does Xanax (alprazolam) calm you down and relax your body. I am prescribed this to calm me down for the night before a procedure.?

Calming receptors. Xanax/alprazolam works on gaba receptors in your brain. These receptors are responsible for calming your brain activity, making your feel less anxious, even sleepy. A calm brain means a relaxed body.
Xanax (alprazolam) Xanax (alprazolam) is a relative of Valium (with fewer side-effects) that depresses certain parts of the brain involved with anxiety. It is commonly used to help patients who get nervous before certain procedures. If you take it at night before a procedure the next day, it may help you get to sleep if the anxiety would have kept you up. But if you are still anxious in the morning, you may need another tablet.