Dipyanone (CAS Number 60996-94-3) is a synthetic opioid compound belonging to the class of 4,4-diphenylheptanone derivatives, making it structurally and pharmacologically related to methadone . It functions as an agonist at the µ-opioid receptor (MOR), κ-opioid receptor (KOR), and δ-opioid receptor (DOR) . Recent pharmacological profiling demonstrates its strong agonistic effect at MOR, with an EC50 of 96.8 nM and 106% maximum effect compared to fentanyl, indicating a potency and efficacy profile similar to methadone that is useful for studying potent analgesic effects . Its activation pattern at opioid receptors also suggests a significant potential for abuse and dependence, making it relevant for research on addiction . Research applications for this compound include fundamental neuropharmacology studies, investigating the mechanisms of opioid receptor activation and signaling, and serving as a comparator substance in studies of opioid receptor binding and affinity . Metabolism studies in humans have shown that this compound is primarily metabolized through the opening of the pyrrolidine ring, leading to specific biomarkers such as 4′-[2-ethylidene-5-methyl-3,3-diphenylpyrrolidin-1-yl]butan-1′-ol (EMDPB) and 4′-[2-ethylidene-5-methyl-3,3-diphenylpyrrolidin-1-yl]butanoic acid (EMDPBA), which are critical for toxicological and forensic analysis . Other metabolic pathways include hydroxylation, reduction, and O-glucuronidation . As a novel synthetic opioid (NSO) first identified on the illicit drug market in 2021, this compound provides a valuable tool for researchers monitoring and characterizing emerging psychoactive substances . This product is provided for Research Use Only (RUO). It is not intended for diagnostic or therapeutic use in humans or animals.