An MS in pharmacology and or toxicology is generally what you will obtain. These are degrees that prepare you for work in the industry or as research assistants. Generally, these are two year degrees and lots of schools have pharmacology programs, and less have toxicology. There are also graduate degrees in industrial pharmacy, pharmacoeconomics, public health, medicinal chemistry, and more. None of these degrees will allow you to do clinical work, only clinical based research at best.
Hope that helps