This publication presents the data and findings of the risk assessment on MT-45 (1-cyclohexyl-4-(1, 2-diphenylethyl)piperazine), carried out by the extended Scientific Committee of the EMCDDA on 16 September 2014. The main part of the publication, the Risk Assessment Report, examines the health and social risks of the drug, information on international trafficking and the involvement of organised crime, and the potential implications of subjecting the drug to control measures. On the basis of this report the Council decided on 8 October 2015 that MT-45 should be subject to control measures across the Member States.