Heroin is a common illicit opioid.
Heroin , also known as diamorphine among other names , is an opiate most commonly used as a recreational drug for its euphoric effects . It is generally illegal to make , possess , or sell heroin without a license . Opiate is a term classically used in pharmacology to mean a drug derived from opium . Opioid , a more modern term , is used to designate all substances , both natural and synthetic , that bind to opioid receptors ( including antagonists ) .