Hein began his career at the
Morehouse School of Medicine, where he chaired the Department of
Pharmacology. In 1989, he was appointed as Professor and Chair of the Department of Pharmacology and Toxicology at the
University of North Dakota, where he became a Chester Fritz Distinguished Professor. In 1997, Hein moved to the
University of Louisville, where he serves as the Peter K. Knoefel Professor and Chair of the Department of Pharmacology & Toxicology and Distinguished University Scholar. Additionally, he has presented the Astor Visiting Lectureship at the
University of Oxford and served as a visiting professor at the
University of Paris. He was elected as a fellow of the Academy of ASPET Pharmacology Educators of the
American Society for Pharmacology and Experimental Therapeutics. ==Research==