MODEL RELEASED. Heroin. Face of an addict behind a hand holding a syringe containing heroin. Heroin (diacetyl morphine) is a white or brownish powder. It can be smoked or sniffed but in this case it has been dissolved in water and will be injected into a vein. Heroin produces feelings of warmth, drowsiness and lack of concern for outside events. Long term use causes tolerance (larger amounts are needed to have the same effect) and dependence (addiction). Infections such as hepatitis B and human immunodeficiency virus can be spread when addicts share needles. Death commonly occurs from accidental overdose.