Heroin
Heroin, (diacetylmorphine) is an addictive drug that is processed from morphine and usually appears as a white or brown powder. The white crystalline form is commonly the hydrochloride salt diacetylmorphine hydrochloride, however heroin freebase may also appear as a white powder. As with other opioids, diacetylmorphine is used as both a pain-killer and a recreational drug, and is commonly regarded as a drug with potential for abuse. Frequent and regular administration is associated with tolerance, moderate physical dependence, and severe psychological dependence, with potential to develop into addiction. Popular street names for the drug include: black tar, horse, smack, junk, and others.