Category: alkaloid
Aliases: 7-OH, 7-OH-mitragynine, 7-hydroxy mitragynine, 7-OHM, 7-hydroxymitragynine
Active μ-opioid metabolite of mitragynine (the principal kratom alkaloid, Mitragyna speciosa). 7-OH is a partial agonist at μ-opioid receptor (MOR) with substantially higher affinity and potency than the parent — published Ki values are in the low-nM range vs mitragynine's hundreds of nM, and animal antinociception is reported at ~10× lower dose than morphine. As a kratom metabolite it accounts for a small fraction of total alkaloid exposure, but commercial "7-OH" tablets and strips concentrate it as the dosed compound (typical serving sizes 5–15 mg). Mixed effects: opioid analgesia + euphoria at higher doses; biased agonism literature suggests reduced respiratory depression vs classical opioids but clinical confirmation is limited and dependence/withdrawal patterns mirror MOR agonists.
PO: 2.5h