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October 6, 2025/News Releases

Cleveland Clinic Study Demonstrates Safety, Effectiveness of Ketamine for Chronic Pain

Low-dose infusions show significant improvement for patients, in one of the largest studies of its kind

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Halle Bishop | 216.312.5086

Low-dose ketamine infusions are both safe and significantly effective for patients with chronic pain, according to one of the largest real-world studies of its kind published today in Regional Anesthesia & Pain Medicine.

Led by researchers at Cleveland Clinic’s Neurological and Primary Care Institutes, the study analyzed data from over 1,000 patients, providing crucial evidence for this emerging treatment approach.

“We know millions of Americans are suffering from chronic pain and this research addresses critical gaps in pain management and shows a significant step forward in improving care for those patients who have otherwise exhausted all other treatment options,” said Pavan Tankha, D.O., medical director of Comprehensive Pain Recovery in Cleveland Clinic’s Neurological Institute. “The findings of the research represent a meaningful step toward improved quality of life and may accelerate access to this treatment option for patients all over the country.”

The retrospective study followed 1,034 patients through a standardized ketamine infusion protocol – 0.5 mg/kg over 40 minutes for five consecutive days – and demonstrated an 86.1% adherence rate, underscoring the feasibility of outpatient administration.

The outpatient ketamine protocol demonstrated strong feasibility, with over 90% of patients completing all five treatment days. Outcomes were measured using the NIH’s PROMIS tool, which assesses physical, mental, and social health. Patients reported notable improvements in pain symptoms and quality of life. The ketamine protocol, delivered within a comprehensive clinical pain program, helped 20% to 46% of patients achieve meaningful improvements in their daily functioning, sleep, and pain management. Additionally, 80% of patients returned for repeat infusions, demonstrating sustained benefit and patient treatment satisfaction.

“This study provides evidence for ketamine's role in chronic pain management,” said Hallie Tankha, Ph.D., a clinical pain psychologist in Cleveland Clinic’s Primary Care Institute and co-investigator of the study. “This is in line with my clinical experience as a pain psychologist, as patients often describe ketamine infusions as ‘life changing.’ I'm encouraged by treatments that can be integrated into comprehensive care approaches, and this study demonstrates ketamine can be safely and effectively implemented in pain management settings.”

Patients were followed for over six months, providing long-term evidence of sustained benefit. Data showed improvements in pain interference, depression, and physical function lasting up to six months, with nearly half of patients showing clinically meaningful improvement in pain-related anxiety.

The research demonstrated that low-dose ketamine was safe, with minimal side effects. Hallucinations, the most reported side effect, were rare. No serious adverse events were reported across the entire cohort. Key advantages of low-dose ketamine include low tolerance risk, feasibility of outpatient administration, and no requirement for anesthesia.

According to the study’s authors, this research highlights the importance of integrating ketamine therapy within a comprehensive pain program, combining infusions with behavioral therapies and patient education. The findings lay the groundwork for larger controlled trials and adoption in multidisciplinary pain centers. This study offers hope for those living with chronic pain who have not responded to conventional treatments.

Ketamine is currently used off label for pain, underscoring the importance of research like this to support FDA approval and broader hospital availability.

About Cleveland Clinic

Cleveland Clinic is a nonprofit multispecialty academic medical center that integrates clinical and hospital care with research and education. Located in Cleveland, Ohio, it was founded in 1921 by four renowned physicians with a vision of providing outstanding patient care based upon the principles of cooperation, compassion and innovation. Cleveland Clinic has pioneered many medical breakthroughs, including coronary artery bypass surgery and the first face transplant in the United States. Cleveland Clinic is consistently recognized in the U.S. and throughout the world for its expertise and care. Among Cleveland Clinic’s 82,600 employees worldwide are more than 5,786 salaried physicians and researchers, and 20,700 registered nurses and advanced practice providers, representing 140 medical specialties and subspecialties. Cleveland Clinic is a 6,728-bed health system that includes a 173-acre main campus near downtown Cleveland, 23 hospitals, 280 outpatient facilities, including locations in northeast Ohio; Florida; Las Vegas, Nevada; Toronto, Canada; Abu Dhabi, UAE; and London, England. In 2024, there were 15.7 million outpatient encounters, 333,000 hospital admissions and observations, and 320,000 surgeries and procedures throughout Cleveland Clinic’s health system. Patients came for treatment from every state and 112 countries. Visit us at clevelandclinic.org. Follow us at x.com/CleClinicNews. News and resources are available at newsroom.clevelandclinic.org.

Editor’s Note: Cleveland Clinic News Service is available to provide broadcast-quality interviews and B-roll upon request. 

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