The market for synthetic drugs has always been characterised by a large variety of substances. Historically, novel (new) psychoactive substances (NPS) have always appeared in this market. However, in recent years, the pace at which these substances have emerged has increased considerably. As the number of NPS increases, so do the potential health problems that some of these substances entail. Often, their appearance is accompanied by an increase in reported health problems, emergency room visits and even fatalities. National and local authorities face numerous challenges when trying to address the issue. Drug analysis laboratories struggle to identify the active ingredients of the substances, as conventional analytical techniques methods often do not provide reliable results. Health care professionals in particular find it difficult to provide proper care as there are few resources on the pharmacology and toxicology of these substances when they first emerge. The present publication narrows this information gap and is the first book to provide a wide spectrum of facts on everything one has always wanted to know about NPS, including information on their chemical structure, their availability, supply and their epidemiology of use.