Compounds classified as “Designer Drugs” have been synthesized for several decades.  This is not a precise scientific term and should only be applied to those drugs that are synthesized from common chemicals and skillfully marketed under attractive, often exotic names. The ingredients used to create these drugs and their potency vary widely, due to the illegal labs and it is nearly impossible to know what, including dangerous contaminants, such as ephedrine or ketamine, are contained in the drugs – leading to dangerous side effects (seizures, coma, and even death). Because of many designer drugs are novel or designed to evade detection, they can be overlooked or difficult to detect or characterize. The last decade has seen a proliferation of such substances, such that keeping abreast of this huge number of new drugs is a difficult task for forensic chemists and toxicologists. The last decade has seen a proliferation of such substances, commonly known as ‘club drugs’ due to their use in night clubs and at parties. Designer Drugs 2013 covers the entire range of known designer drugs up to December 2012.  Compiled by a team originating from the Regional Departments of Criminal Investigation in Kiel, Hamburg, and Wiesbaden, Germany, Mass Spectra of Designer Drugs has been developed to help forensics and toxicology labs combat this epidemic. Approximately 70% of the compounds covered in the Designer Drugs do not appear in either NIST 2011 or the Wiley Registry of Mass Spectral Data, 10th Edition.