Hans Geyer is based at the Institute for Biochemistry which is part of the German Sports University in Cologne. He is internationally recognises as one of the world’s leading experts on doping in sport and has been responsible for many of the advances in analytical methods in recent years. He was the first to draw attention to the problem of contamination of dietary supplements with pharmaceuticals that could cause an adverse analytical finding in an athlete’s urine. He was also the first to identify the problem of drug residues in meat products leading to positive doping outcomes.