Kratom Hospitalizations Rose 15% Per Year at Mass General Brigham System, Harvard Study Finds

Why it matters

A Harvard-affiliated academic medical center documented a statistically significant 15% annual increase in kratom-related hospitalizations over seven years, signaling that clinicians nationwide need to screen for kratom use more systematically.

The big picture

Kratom use in the U.S. is widespread, with estimates of past-year users ranging from 1.6 million (NSDUH 2023) to as many as 9% of adults. Despite this, most health systems lack systematic data on kratom's clinical burden. This study provides one of the first longitudinal looks at kratom's trajectory within a large academic hospital system. The authors also raise concern about the proliferation of 7-hydroxymitragynine (7-OH) products, which the FDA in July 2025 recommended scheduling under the Controlled Substances Act.

Key findings

• Kratom mentions in hospitalizations at Mass General Brigham increased at a statistically significant average annual rate of 14.9% from 2017 to 2024 (95% CI, 8.3%–22.0%; p=0.001)
• The sharpest increase was from 2017 to 2020, with a 45.4% annual percentage change (p<0.001), followed by a slower increase through 2024
• 224 emergency department encounters and 1,098 hospitalizations mentioning kratom were identified via free-text search of clinician notes
• Most encounters involved male patients (79% of ED visits, 70% of hospitalizations) and adults aged 20–49
• Authors express concern about the growing availability of 7-hydroxymitragynine (7-OH), a potent mu-opioid agonist now recommended for federal scheduling

What they say

Clinicians should routinely inquire about kratom use and inform patients of its risks and benefits. While additional research on kratom's therapeutic potential may be warranted, a focus on the serious adverse effect profile from kratom, 7-hydroxymitragynine, and other kratom alkaloids is urgently needed. — Kopczynski A et al., JAMA Network Open, March 17, 2026

Bottom line

Kratom-related hospitalizations at one of the nation's largest academic medical center systems grew nearly 15% annually over seven years — a trend researchers say demands routine clinical screening and urgent research into adverse effects.