6-monoacetylmorphine (6-MAM)

6-monoacetylmorphine (6-MAM) is a pharmacologically active intermediate metabolite of heroin (diacetylmorphine). Following heroin administration, the parent drug is rapidly deacetylated by esterases in the blood and brain to form 6-MAM, which is then more slowly metabolized into morphine. 6-MAM is significantly more lipophilic than morphine, allowing it to cross the blood-brain barrier with high efficiency and contribute to the rapid, intense euphoria or "rush" associated with heroin use. It exerts its effects primarily as a potent agonist at the mu-opioid receptor, leading to profound analgesia, sedation, and potentially lethal respiratory depression. In forensic and clinical toxicology, 6-MAM serves as a definitive biomarker for recent heroin consumption because it is not produced by the metabolism of other common opioids like codeine or morphine. While it is a bioactive molecule, it is classified as a drug metabolite rather than a therapeutic target.

Other names

6-MAM6-AcetylmorphineO6-MonoacetylmorphineHeroin metabolite

6-monoacetylmorphine acts as a potent agonist at the mu-opioid receptor (MOR) in the central nervous system, mimicking the effects of endogenous opioids.