7-Hydroxymitragynine
7-OH · CAS 174418-82-7
Formula
C₂₃H₃₀N₂O₅
Molecular Weight
414.5 g/mol
Abundance in Leaf
≤2%
Last Reviewed
2026-03-12
What Is 7-Hydroxymitragynine?
7-Hydroxymitragynine (7-OH) is a trace alkaloid in kratom leaves, typically making up less than 2% of total alkaloid content. Despite its low concentration, it is roughly 13 times more potent than morphine at the mu-opioid receptor and is considered a major contributor to kratom's analgesic effects. It is formed partly through oxidation of mitragynine, both in the plant and during human metabolism (CYP3A4 converts mitragynine to 7-OH in the liver). Like mitragynine, 7-OH is a G-protein-biased agonist — it preferentially activates pain-relief signalling while producing less beta-arrestin-2 recruitment than classical opioids, which may translate to reduced respiratory depression and constipation. If you see "7-OH" on a Certificate of Analysis, this is the compound being measured. Regulatory attention has focused on 7-OH due to its potency, and several states have enacted concentration limits for it in consumer products.
Dose-Dependent Effects
As part of whole-leaf kratom
- Contributes significantly to analgesia even at low leaf doses
- At higher leaf doses, increases sedation and euphoria
- Effects are modulated by co-occurring alkaloids (especially mitragynine)
As reported in Kruegel & Grundmann 2018; Matsumoto et al. 2004, not a recommendation.
Receptor Activity
Safety & Adverse Effects
Potency warning
7-OH is significantly more potent than mitragynine at the mu-opioid receptor. Concentrated or synthetic 7-OH products carry higher risk of adverse effects including respiratory depression, especially when combined with other CNS depressants.
Source: Kruegel & Grundmann 2018; FDA advisory 2021
Dependence potential
Due to its high mu-opioid potency, 7-OH may contribute disproportionately to dependence development from regular kratom use, despite being present in low concentrations in leaf material.
Source: Matsumoto et al. 2005; Hemby et al. 2019
Regulatory status
Several U.S. states have enacted concentration limits for 7-OH in consumer kratom products under the Kratom Consumer Protection Act framework. Some jurisdictions treat concentrated 7-OH products differently from whole-leaf kratom.
Source: AKA KCPA model legislation
Drug Interactions
CYP3A4 inhibitors (ketoconazole, grapefruit juice)
major7-OH is produced from mitragynine via CYP3A4. Inhibitors may alter the mitragynine-to-7-OH conversion ratio, potentially affecting potency and duration.
CNS depressants (benzodiazepines, alcohol, opioids)
majorAdditive sedation and respiratory depression risk. The high mu-opioid potency of 7-OH makes this combination particularly dangerous.
MAOIs
majorTheoretical risk of serotonin syndrome and unpredictable potentiation of opioid effects. Avoid combination.
COA Connection
Appears on Certificates of Analysis as: 7-OH. Graded under P_acc (Potency Accuracy) (Key safety metric).
View graded productsCited Literature
Kruegel AC, Grundmann O (2018). The medicinal chemistry and neuropharmacology of kratom: A preliminary discussion of a promising medicinal plant and analysis of its potential for abuse. ACS Chem Neurosci.
DOI: 10.1021/acschemneuro.7b00579Váradi A, Marrone GF, Palmer TC, et al. (2016). Mitragynine/corynantheidine pseudoindoxyls as opioid analgesics with mu agonism and delta antagonism, which do not recruit β-arrestin-2. J Am Chem Soc.
DOI: 10.1021/jacs.6b00360Matsumoto K, Horie S, Ishikawa H, et al. (2004). Antinociceptive effect of 7-hydroxymitragynine in mice: Discovery of an orally active opioid analgesic from the Thai medicinal herb Mitragyna speciosa. Life Sci.
DOI: 10.1016/j.lfs.2003.10.006Hemby SE, McIntosh S, Leon F, et al. (2019). Abuse liability and therapeutic potential of the Mitragyna speciosa (kratom) alkaloids mitragynine and 7-hydroxymitragynine. Addict Biol.
DOI: 10.1111/adb.12639