Systematic Review: Kratom-Associated Liver Injury Cases Documented in Published Literature

Why it matters

Liver injury is one of the most serious adverse effects associated with kratom use, with documented cases including progression to transplantation. Clinicians need better understanding of causality and risk factors.

The big picture

Kratom has been marketed as a natural dietary supplement for pain, anxiety, and opioid withdrawal. However, accumulating case reports raise concerns about hepatotoxicity. This systematic review synthesizes published evidence on kratom-associated liver injury to characterize patterns and inform clinical decision-making.

Key findings

• Thirty-one studies identified 32 cases of kratom-associated liver injury; most were single-patient case reports from the US; patients were predominantly adult males with polysubstance use and comorbidities; liver injury patterns were predominantly cholestatic; in most cases, liver enzymes improved after kratom cessation; in 4 cases, liver function progressed to transplantation; exposure details (dose, frequency, duration) were incompletely reported in most cases

What they say

Researchers stated: "Further research is needed to better characterize kratom's mechanisms of liver injury and to inform clinical decision-making and public health policy."

Bottom line

**Kratom's association with liver injury is established, but incomplete reporting of exposures and limited mechanistic understanding complicate assessment of causality and risk factors.**