While overall drug use in the U.S. dropped sharply through the Eighties, heroin use remained relatively steady. During the Nineties, it started to rise, as the addict population grew and changed. Known on the street as smack, horse, H, junk, or scag, heroin is the most commonly abused of narcotics. Heroin is a morphine derivative , and morphine is opium's most potent active ingredient. First synthesized in 1874, heroin was widely used in medicine in the early part of the 20th Century, until its addictive potential was recognized.
Pure heroin is a white powder with a bitter taste.
Street heroin may vary in color from white to dark brown because of impurities or additives. Produced in Mexico, it is widely available in the western United States. Street heroin is rarely pure. In 1980, the average bag was only 4 percent pure heroin. By the mid-Nineties, however, purity was generally 40 percent or higher.