Category: alkaloid
Aliases: kratom alkaloid, Mitragyna speciosa alkaloid
The principal indole alkaloid of kratom (Mitragyna speciosa); a G-protein-biased partial agonist at the µ-opioid receptor, producing stimulant-like effects at low doses and opioid-like analgesia/sedation at higher doses. Its CYP3A-derived metabolite 7-hydroxymitragynine is a far more potent MOR agonist and contributes substantially to the in-vivo opioid effect. Reported G-protein bias is hypothesized to limit respiratory depression, though dependence and withdrawal still occur.
PO: 23.24h
PubChem CID 3034396. Parent alkaloid of the registry's 7-hydroxymitragynine metabolite. PK: Trakulsrichai 2015 (PMID:25995615), first human PK study, verbatim "terminal half-life (23.24±16.07 hours)". Opioid Ki/EC50 SKIP — real but table/figure-only in every abstract (see AUTHORING_GAPS).