Kratom: A Comprehensive Systematic Review of Toxicological Issues

Why it matters

This peer-reviewed forensic toxicology systematic review consolidates everything known about kratom's pharmacology, adverse effects, and analytical detection — essential reading for clinicians and policymakers navigating kratom's complex risk-benefit profile.

The big picture

As kratom proliferates in Western markets without regulatory oversight, forensic and clinical toxicologists are grappling with inconsistent data on its safety. This systematic review highlights the urgent need for standardized regulation and more rigorous human studies.

Key findings

• • Kratom contains 50+ alkaloids; mitragynine and 7-hydroxymitragynine are primary compounds with mu-opioid receptor affinity
• • Mitragynine's multimodal mechanism includes adrenergic, serotonergic, and opioid-like effects — making it pharmacologically distinct from classic opioids
• • Adverse effects including fatalities have been associated with kratom use, most commonly in polydrug contexts
• • Lack of regulatory control, easy online access, and low cost have driven escalating use among people with opioid use disorder
• • The "natural = safe" perception drives widespread unsupervised use despite significant toxicological risks

Bottom line

Systematic review by forensic scientists at Sam Houston State University and the San Francisco Chief Medical Examiner's Office; published in WIREs Forensic Science (2022).