How long should a person take adipex before it can become harmful? are there cases of it hurting your liver?

As short as possible: Appetite suppressant, speed'like drug. Works best for short-term use (< 3-6 wks), after that less effective, but more likely to cause dependency, risks for cardiovasc problems including high bp, valve disease, angina, pulmonary disease, etc. Can't suddenly stop it if used for a long time. Any drug metabolized by liver can cause liver problems-this can too.