Entactogens

Their own subject because both neighbours would be half right. Entactogens release serotonin by reversing the transporter that normally clears it, with noradrenaline and dopamine released alongside; the prosocial effect the class is named for follows from that release and the signalling downstream of it, not from 5-HT2A agonism as in Psychedelics and not from reuptake blockade as in Stimulants. Three structural families sit here: the methylenedioxy phenethylamines, their β-keto cathinone versions, and the benzofurans.

What varies is the ratio — how much serotonin against how much dopamine a member releases, and whether it carries psychedelic or stimulant character on top. The class-level harms come straight from the mechanism: serotonin syndrome with MAOIs, SSRIs and the β-carbolines filed under Psychedelics; hyperthermia once heat and exertion are added; hyponatraemia when water is drunk against the fluid retention these drugs cause; and cardiovascular strain.