Heroin is a drug and member of the opiate family; the substances taken from the opium poppy. Cutting the unripe seedpods of the opium poppy with a knife and drying the milky juice leaves raw opium. One of the main constituents of opium is morphine from which heroin is synthesized. By the time the heroin gets to the user, dealers have cut it with all kind of other substances like caffeine, sugars, starch or licorice tablets. heroin, as sold on the street, consists of approximately 20-80% of pure heroin. Its appearance varies from crude white powder to yellow brownish chunks. heroin is also called dope, junk or smack.