Last Updated July 16, 2004

Heroin is processed from morphine, a naturally occurring opiate extracted from the seedpod of certain varieties of poppies. Street heroin is rarely pure and may range form a white to dark brown powder of varying consistency. Such differences typically reflect the impurities remaining from the manufacturing process and/or the presence of additional substances. These "cuts" are often sugar, starch, powdered milk and occasionally other drugs, which are added to provide filler.

Heroin is manufactured from opium poppies cultivated in four primary source areas: South America, Southeast and Southwest Asia, and Mexico. High purity, South American (Colombian) white heroin has become the most prevalent type available in the United States, particularly in the Northeast, South and Midwest. The particular form known as "black tar" from Mexico, a less pure form of heroin, is more commonly found in the western and southwestern United States. This heroin may be sticky like roofing tar or hard like coal, with its color varying from dark brown to black.

Heroin can be sniffed, smoked or injected. Mexican black tar heroin, however, is usually injected (once dissolved) or smoked because of its consistency. Like other opiates, heroin is a sedative drug that slows body functioning. users describe a feeling of warmth, relaxation and detachment, with a lessening sense of anxiety. Initial use can result in nausea and vomiting, but these reactions fade with regular use.

Injection poses the greatest risk of lethal overdose by enabling large amounts of heroin (and additional contaminants if any) into the bloodstream at once. Smoking and snorting heroin can also result in overdose, especially if a non-tolerant user ingests a large amount of potent heroin and/or combines it with other depressant drugs, such as alcohol. Symptoms of a heroin overdose include slow and shallow breathing, convulsions, coma and possibly death.

The use of "dirty" or shared needles when injecting heroin can spread deadly infectious diseases such as HIV and Hepatitis B and C.