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. NIDA researchers have confirmed that all forms of heroin administration are addictive.

Route of Administration Among Heroin Treatment Admissions in Selected Areas Source: Community Epidemiology Work Group, NIDA, December 2003, Vol. II.
*Includes first half 2003 data from treatment facilities.

Injection continues to be the predominant method of heroin use among addicted users seeking treatment; in many CEWG areas, heroin injection is reportedly on the rise, while heroin inhalation is declining. However, certain groups, such as White suburbanites in the Denver area, report smoking or inhaling heroin because they believe that these routes of administration are less likely to lead to addiction.

With the shift in heroin abuse patterns comes an even more diverse group of users. In recent years, the availability of higher purity heroin (which is more suitable for inhalation) and the decreases in prices reported in many areas have increased the appeal of heroin for new users who are reluctant to inject. Heroin has also been appearing in more affluent communities.