Study of 156 Kratom-Associated Deaths Finds Polysubstance Use in 87% of Cases, Kratom Alone Implicated in Just 23%

Why it matters

This systematic analysis of 156 kratom-associated fatalities is one of the most detailed examinations of who is dying and why — and it finds that the vast majority involve other drugs, complicating the assignment of causation to kratom alone.

The big picture

The finding that kratom alone was implicated in only 23% of cases is a key data point in ongoing regulatory debates: it challenges narratives that kratom is straightforwardly lethal while also highlighting the danger of polysubstance combinations. Understanding these deaths accurately requires toxicological reporting that distinguishes kratom as a contributing factor versus a cause.

Key findings

• • 156 kratom-associated deaths analyzed; 80% male, mean age 32.3 years
• • 95% of decedents had a drug abuse history prior to death
• • Polysubstance use was present in 87% of cases, typically involving controlled/recreational drugs, therapeutic medications, or alcohol
• • Mitragynine was identified as the sole substance implicated in only 23% of cases
• • Reasons for kratom use included self-medication, recreation, relaxation, bodybuilding, and attempting to avoid positive drug tests
• • IV LD50 of mitragynine in rats is similar to that of heroin (27.8 vs 23.7 mg/kg), but oral LD50 is much higher (547.7 mg/kg)

What they say

University of Hertfordshire and University of London research team; cases identified from UK mortality registers and global media/database searches; descriptive statistical and thematic analysis; Journal of Psychopharmacology, 2019.

Bottom line

Kratom's role in overdose deaths is rarely straightforward — the overwhelming majority of cases involve other substances, and the rare kratom-only deaths remain poorly characterized, underscoring the need for standardized toxicological reporting.