Heroin is typically sold as a white or brownish powder or as the black sticky substance known on the streets as "black tar heroin." Although purer heroin is becoming more common, most street heroin is "cut" with other drugs or with substances such as sugar, starch, powdered milk or quinine. Street heroin can also be cut with strychnine or other poisons.
Heroin is usually injected, sniffed/snorted, or smoked. Typically, a heroin abuser may inject up to four times a day. Intravenous injection provides the greatest intensity and most rapid onset of euphoria (7 to 8 seconds), while intramuscular injection produces a relatively slow onset of euphoria (5 to 8 minutes). When heroin is sniffed or smoked, peak effects are usually felt within 10 to 15 minutes. Although smoking and sniffing heroin do not produce a "rush" as quickly or as intensely as intravenous injection, all three forms of heroin administration are still highly addictive.
Short-term effects include a surge of euphoria followed by alternately wakeful and drowsy states and cloudy mental functioning. Users who inject the drug are more prone to fatal overdose and infectious diseases such as HIV/AIDS and hepatitis. Long-term users may develop collapsed veins, liver disease, and lung complications.
Because heroin abusers do not know the actual strength of the drug or its true contents, they are at risk of overdose or death. Heroin also poses special problems because of the transmission of HIV and other diseases that can occur from sharing needles or other injection equipment.
Injection continues to be the predominant method of heroin use among addicted users seeking drug treatment; however, researchers have observed a shift in heroin use patterns, from injection to sniffing and smoking. In fact, sniffing/snorting heroin is now a widely reported means of taking heroin among users admitted for drug rehab, and younger heroin users often use this method.
With the shift in heroin abuse patterns comes an even more diverse group of users. Older users (over 30) continue to be one of the largest user groups in most national data. However, several sources indicate an increase in new, young users across the country who are being lured by inexpensive, high-purity heroin that can be sniffed or smoked instead of injected.