
Heroin is a semisynthetic substance derived from morphine. Among the most powerful painkillers known, it is a highly dangerous drug because it causes severe psychological and physical addiction.
Upon entering the brain, heroin acts in areas involved in pain perception and gratification, producing a surge of euphoria ("rush") accompanied by dry mouth, hot red skin, heavy limbs and mental confusion with a sensation of flying, which alternates between being fully awake or asleep.
Short- and long-term risks are: