Anabolic androgenic substances (AAS) increase muscle mass, reduce total body fat and induce a positive nitrogen balance, resulting in higher performance. Therefore the use of AAS in competitive sports is of extreme attractivness but strictly illegal. In animal husbandry the application of AAS is legal in some countries but forbidden in the EU. Also in medical therapies anabolic agents are applied. The residue analysis methods for AAS are mostly based on confirmation of suspected samples via substance identification by mass spectrometry. It is also known that AAS can influence mRNA expression of specific genes. The aim of this thesis was to proof the possibility to detect AAS treatment via mRNA expression analysis. With the identification of biomarkers for anabolic agents using qRT-PCR, a gene expression pattern for AAS and metabolic pathways should be identified. First tissue specific biomarkers and effects on metabolic pathways could be detected. Theses biomarkers can be taken to establish a screening pattern for anabolic agents. Therefore, first steps toward a new screening method for anabolic agents could be done, helping to uncover abuses of anabolic agents in the future.