Heroin

What is Heroin?

Heroin is a powerful illegal opioid derived from morphine and sold in several forms, including powder and tar. Because it enters the brain rapidly, heroin produces a strong euphoric “rush,” followed by deep relaxation and sedation. The absence of any medical use and the high risk of addiction classify heroin as a Schedule I substance under U.S. federal law.

Recreational use involves injecting, snorting, or smoking the drug, each carrying significant health dangers—including infection, collapsed veins, severe withdrawal, and a high likelihood of overdose. The increasing prevalence of fentanyl-laced heroin has further elevated overdose deaths, as users often have no awareness of the added potency. Long-term heroin use alters brain chemistry, leading to compulsive drug-seeking behavior and profound physical dependence.

In drug-monitoring environments, heroin presents unique challenges because its metabolites, particularly 6-monoacetylmorphine (6-MAM), have a short detection window. Nevertheless, its legal status and public health impact ensure that heroin remains a core target in nearly all modern toxicology programs.

Effects:

• Intense euphoria followed by heavy sedation

• Warm, flushed skin and slowed breathing

• “Nodding off” — alternating drowsiness and wakefulness

• Severe itching

• Nausea and vomiting

• Constricted (“pinpoint”) pupils

• Slowed heart rate and decreased blood pressure

• High risk of overdose and respiratory arrest

• Rapid development of tolerance and dependence

• Long-term cognitive decline and impaired decision-making