Science
Mixture compounds
Concentrated 7-OH products often contain, or are sold next to, related alkaloids. Here is what published sources say about the main ones.
Related compounds
Mitragynine
Main leaf alkaloid (~66% of alkaloids); low in 7-OH products.
MOR Ki 78-233 nM; weak partial agonist (Emax ~34%); KOR/DOR antagonist; alpha-adrenergic (uM); hERG IC50 0.3-1.6 uM.
Harms noted: Dependence with heavy use; QT prolongation risk at high exposures; liver injury (rare, cholestatic); seizures reported in heavy kratom use.
Refs: PMID 27192616; 31874991; 38474495
Mitragynine pseudoindoxyl (MGPI)
Sold alone or with 7-OH (Hill 2025; White 2025).
Mouse MOR Ki 0.8 nM, DOR 3 nM; MOR agonist EC50 1.7 nM Emax 84%; DOR antagonist; little beta-arrestin (Varadi 2016).
Harms noted: Animal data suggest less respiratory depression than morphine, but human case of severe early withdrawal (Stanciu 2026). Human safety unknown.
Refs: PMID 27556704; 40568898
MGM-15 (dihydro-7-OH)
'Research chemical' tablets (~10.9 mg/tablet, Gour 2025).
Guinea-pig MOR Ki 6.4 nM, DOR 16 nM (Matsumoto 2014); more potent than 7-OH in ileum.
Harms noted: Assume opioid toxidrome; no human data.
Refs: PMID 24345467; 40936282
MGM-16
Emerging 'next-gen' kratom-derived products (DEA/market reports).
Very high MOR affinity in vitro (sub-nM reported; Matsumoto 2014); potent analgesic in mice.
Harms noted: Assume potent opioid; no human data.
Refs: PMID 24345467
How they connect chemically
- 7-Hydroxymitragynine (7-OH) — natural constituent — Mitragynine: Both occur naturally in kratom leaf; 7-OH only in trace amounts
- 7-Hydroxymitragynine (7-OH) — metabolite of — Mitragynine: 7-OH is a liver (CYP3A4) metabolite of mitragynine
- Mitragynine pseudoindoxyl (MGPI / "pseudo") — metabolite of — 7-Hydroxymitragynine (7-OH): MGPI forms from 7-OH in human plasma
- 7-Hydroxymitragynine (7-OH) — lab modified derivative — Mitragynine: Commercial 7-OH concentrates are semi-synthetic, made from mitragynine rather than extracted (no process detail)
- Mitragynine pseudoindoxyl (MGPI / "pseudo") — lab modified derivative — 7-Hydroxymitragynine (7-OH): Commercial MGPI is lab-made in the same family
- MGM-15 (dihydro-7-OH) — lab modified derivative — 7-Hydroxymitragynine (7-OH): MGM-15 is a lab-modified derivative in the 7-OH family
- MGM-16 (fluoro-dihydro-7-OH) — lab modified derivative — MGM-15 (dihydro-7-OH): MGM-16 is a lab-modified derivative in the same family
- 3-Dehydromitragynine and other semi-synthetic by-products — co found — 7-Hydroxymitragynine (7-OH): By-products found alongside 7-OH in semi-synthetic products
- Mitragynine pseudoindoxyl (MGPI / "pseudo") — co found — 7-Hydroxymitragynine (7-OH): 71% of MGPI products also had 7-OH
- MGM-15 (dihydro-7-OH) — co found — 7-Hydroxymitragynine (7-OH): CFSRE found MGM-15 with 7-OH in drug materials
- Mitragynine pseudoindoxyl (MGPI / "pseudo") — marketed substitute — 7-Hydroxymitragynine (7-OH): "Pseudo" products marketed as stronger next step as 7-OH faced bans
- MGM-15 (dihydro-7-OH) — marketed substitute — Mitragynine pseudoindoxyl (MGPI / "pseudo"): MGM-15 tablets kept selling after MGPI scheduling; DEA covered both
- SR-17018 — marketed substitute — 7-Hydroxymitragynine (7-OH): Sold as a "7-OH alternative" after 7-OH scheduling announcement; unrelated chemistry
- Tianeptine — co shelved — 7-Hydroxymitragynine (7-OH): Same gas-station/smoke-shop channel; not found inside 7-OH products
- Phenibut — co shelved — 7-Hydroxymitragynine (7-OH): Same channel; found in a non-kratom smoke-shop product
- Fentanyl — co detected in cases — 7-Hydroxymitragynine (7-OH): Co-use in death cases, not a product ingredient
- Hemp-derived semi-synthetic intoxicants (class label only) — co shelved — 7-Hydroxymitragynine (7-OH): Same retail channel (class label only)