Heroin was first synthesized in 1874 from morphine, a naturally occurring substance extracted from the seed pod of certain varieties of poppy plants. Heroin comes in various forms, but pure heroin is a white powder with a bitter taste. Heroin can be injected, smoked, or snorted. Intravenous injection produces the greatest intensity and most rapid onset of euphoria. After ingestion, heroin crosses the blood-brain barrier. While in the brain, heroin converts to morphine and binds rapidly to opioid receptors. Users tend to report feeling a "rush" or a surge of pleasurable sensations. Repeated heroin use produces tolerance and physical dependence, which causes the user's body to adapt to the presence of the drug, and withdrawal symptoms occur if use is reduced. Chronic heroin use can lead to medical consequences such as scarred and/or collapsed veins, bacterial infections of the blood vessels and heart valves, abscesses and other soft-tissue infections, and liver or kidney disease. Poor health conditions and depressed respiration from heroin use can cause lung complications. An approximate estimate of the hardcore addict population in the United States places the number between 750,000 and 1,000,000 users. Heroin users are predominantly White males, over age 30, who live in central city areas. During 2002, the percentage of adult male arrestees testing positive ranged from 0 percent in Woodbury, IA, to 26 percent in Chicago. During 1990 Americans consumed 13.6 metric tons of heroin. Current estimates of heroin consumption remain relatively unchanged and show that 13.3 metric tons of heroin were consumed in 2000. This report provides information and data on production and trafficking, as well as price and purity. Enforcement information addresses arrests, seizures, adjudication, and corrections. Heroin users accounted for 15.2 percent of all treatment admissions in 2000. Methadone has been used to treat opioid addiction for more than 30 years. This synthetic narcotic suppresses opioid withdrawal symptoms for 24 to 36 hours. Although the patient remains physically dependent on the opioid, the craving from heroin use is reduced, and the highs and lows are blocked. This permits the patient to be free from the uncontrolled, compulsive, and disruptive behavior associated with heroin addiction. Currently, heroin falls under Schedule I of the Controlled Substances Act, indicating that it has a high potential for abuse, is not currently accepted for medical use in treatment in the United States, and lacks accepted safety for use under medical supervision. 27 references