Seized heroin. Gloved hand of a police officer holding a stash of heroin that was found during a drug raid on a flat. Heroin (diacetylmorphine) is an opiate (derived from opium), narcotic (stupor- inducing), analgesic (pain-alleviating) drug, which induces dependence and tolerance in users very quickly. Tolerance leads to ever-higher doses being taken, often leading to fatal overdose. Heroin may be smoked or injected. Gloves are worn by the police when handling evidence to avoid contamination.