I'm scared to take xanax (alprazolam). What are some side effects?

Depends on what you. Are taking it for. If you have occasional anxiety (like fear of flying) it will calm you down and make it easier to overcome your fears. Taken regularly for generalized anxiety disorder it can improve symptoms as well, but it is short-acting, and only lasts a few hours. There are other ways to treat anxiety including antidepressant meds and psychotherapy. It can produce physical dependency/abuse.