I ran out of Xanax. What's the Xanax withdrawal like?

The withdrawal is not going to be the same for everyone.  A dosage of 0.5 mg once nightly is fairly low.  There may be little or no withdrawal, particularly if the drug has been taken for only a few weeks or months.  Sometimes withdrawal can be more uncomfortable, but this is a dosage not usually associated with serious complications such as seizures.  I know that there are a lot of scary stories about Xanax withdrawal on the Internet, but the people who had little difficulty are not going to be motivated to post on a message board.  Because expectation and placebo play a large part in the Xanax withdrawal experience, you want to hope for the best and have a positive attitude.