6monoacetylmorphine

6-Monoacetylmorphine, commonly abbreviated 6-MAM, is an opioid metabolite derived from diacetylmorphine (heroin). It is the acetyl ester of morphine at the 6-position, formed when heroin is metabolized by body esterases. Because the 6-acetyl group increases lipophilicity, 6-MAM crosses the blood–brain barrier rapidly and contributes to heroin’s quick onset of effects. It is subsequently hydrolyzed to morphine, which extends the duration of action.

Pharmacologically, 6-MAM acts as a μ-opioid receptor agonist and shares analgesic and sedative effects with other opiates. Its pharmacokinetic profile is characterized by rapid appearance after heroin administration and swift decline as it is converted to morphine; the intact compound can be detected in blood and urine shortly after use and contributes to the overall opioid effect.

In forensic toxicology, 6-MAM serves as a specific biomarker for heroin exposure because it is produced from heroin and not from most other opioids. Drug screening often includes assays for 6-MAM, with confirmation by GC-MS or LC-MS/MS identifying its presence and distinguishing heroin use from other opiate use.

Legal status generally treats 6-MAM as a metabolite of heroin rather than as a separate scheduled substance, though its detection indicates heroin exposure and is routinely used in toxicology to confirm heroin use.

Safety considerations reflect the risks associated with all opioids, including dependence, tolerance, and potentially life-threatening respiratory depression. 6-MAM’s role is primarily as a pharmacologically active metabolite that contributes to heroin’s rapid and potent effects.