MODEL RELEASED. Heroin addict. Young man injecting himself with a heroin solution using a hypodermic needle. Heroin is an addictive, tolerance-building narcotic drug derived from opium. It is a strong painkiller (analgesic) when used medically, but uncontrolled recreational use can rapidly lead to addiction. It produces a feeling of extreme relaxation and warmth. Injecting the drug carries a high risk of infection. Needles are often shared between users, encouraging the spread of diseases such as AIDS (acquired immune deficiency syndrome) and hepatitis. Overdoses can easily be fatal, and giving up the drug is difficult due to the unpleasant side-effects withdrawal entails.