Dark Classics in Chemical Neuroscience: NBOMes

N-Benzylphenethylamines, commonly known as NBOMes, are synthetic psychedelic compounds derived from the phenethylamine class of psychedelics (2C-X compounds), which originally have been derived from the naturally occurring alkaloid mescaline. Analogously to their parent compounds and other classical psychedelics, such as psilocybin and LSD, NBOMes are believed to exert their main pharmacological effects through activation of serotonin 2A (5-HT2A) receptors. Since their introduction as New Psychoactive Substances (NPSs) in 2010, NBOMes have been widely used for recreational purposes; this has resulted in numerous cases of acute toxicity, sometimes with lethal outcomes, leadingto the classification of several NBOMes as Schedule I substances, in 2013. However, in addition to their recreational use, the NBOMe class has yielded several important biochemical tools, including [11C]Cimbi-36, which is now being used in positron emission tomography (PET) studies of the 5-HT2A and 5-HT2C receptors in the mammalian brain, and 25CN-NBOH, one of the most selective 5-HT2A receptor agonists developed to date. In this review, the history, chemistry and structure-activity relationships, ADME properties and safety profiles of NBOMes will be outlined and discussed.