ORN Spring 2026: Update on the diversification of kratom-derived products: 7-hydroxymitragynine, pseudoindoxyl, and beyond-Handout - ORN Spring 2026

Handout - ORN Spring 2026 - Smith

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This presentation (May 6, 2026) reviews the rapid diversification of kratom-derived products—especially those containing 7-hydroxymitragynine (7‑OH), and emerging compounds such as mitragynine pseudoindoxyl—focusing on pharmacology, toxicology, use patterns, and abuse-potential indicators.<br /><br />Mitragynine (MG), a major kratom alkaloid (roughly 34–55% of leaf alkaloids), is described as a weak, partially binding mu-opioid receptor (MOR) agonist with additional adrenergic activity and downstream dopaminergic effects; it may act synergistically with other minor alkaloids. Rat oral bioavailability estimates for MG preparations range from ~17–31%. 7‑OH, an MG metabolite/alkaloid, is highlighted as a highly selective MOR agonist with higher binding affinity than MG and morphine, though it may not occupy all MOR subtypes and has been characterized as partial or full agonist; its oral bioavailability is reported as low (~2.7%). Animal studies indicate MG and 7‑OH can be tolerated at certain doses, and both are self-administered by nonhuman animals; translation to human abuse liability remains uncertain, and no formal human abuse-potential studies exist. Respiratory depression has been observed in mice for MG and 7‑OH, with mixed rat findings; human risk is unclear.<br /><br />Clinical/survey data suggest growing 7‑OH use: in one kratom clinical trial, ~16% reported past-month 7‑OH use since July 2024. Using existing kratom-use estimates, the speaker suggests a potential millions-level 7‑OH consumer population. In a sample (N=278; March–May 2025), most first tried 7‑OH after 2022. Common discovery sources were vape shops and Reddit; purchasing often occurred via vape shops and online. Typical reported use was multiple doses daily with rapid onset (~26 minutes) and hours-long effects; 44% reported unwanted effects, with rare medical care seeking. Many viewed effects as habit-forming yet beneficial, and some used 7‑OH as a replacement for kratom products. Toxicology and poison center data are early/limited but include single-substance 7‑OH exposures and a small number of severe cases.<br /><br />Regulatory context is evolving: in July 2025 FDA recommended scheduling 7‑OH as Schedule I; DEA had not publicly acted at the time noted. The talk concludes with clinical assessment/intervention considerations and emphasizes demand is unlikely to disappear solely through scheduling.

Keywords

kratom-derived products

7-hydroxymitragynine (7-OH)

mitragynine (MG)

mitragynine pseudoindoxyl

mu-opioid receptor (MOR) agonist

pharmacology and toxicology

oral bioavailability

abuse potential and self-administration

respiratory depression risk

FDA scheduling recommendation (Schedule I)