Preclinical Review Links Kratom to Epigenetic Changes and Cardiac Risks

As the opioid crisis continues to limit access to traditional analgesics, an increasing number of patients are turning to kratom (Mitragyna speciosa) for the self-management of chronic pain and opioid withdrawal [1, 2]. While marketed as a natural supplement, this botanical contains complex alkaloids such as mitragynine, which functions as a partial mu-opioid agonist (a compound that binds to and activates opioid receptors but with lower maximal efficacy than full agonists like morphine), leading to documented physical dependence and neonatal abstinence syndrome [3, 4]. Clinical reports have linked its use to severe adverse events, including cholestatic liver injury (a condition where bile flow from the liver is slowed or blocked) and a 1,200% increase in poison control center calls between 2015 and 2025 [5, 6]. Despite its widespread availability, the lack of standardized dosing and rigorous pharmacokinetic data (the study of how the body absorbs, distributes, and eliminates a substance) leaves physicians with little guidance on managing patients who use these products [7, 8]. A new systematic review of 20 studies clarifies the underlying molecular landscape, revealing that chronic exposure may increase the expression of histone deacetylase 2 (an enzyme that modifies gene regulation) and identifies Rab35 as a potential protein biomarker for withdrawal [9].