Study links GLP-1 weight-loss drugs to rare cases of Wernicke encephalopathy
An Israeli review of FDA adverse-event reports identified 15 instances of Wernicke encephalopathy among users of GLP-1 medications, prompting calls for further investigation.
An analysis of U.S. Food and Drug Administration adverse-event reports and related literature uncovered 15 cases of Wernicke encephalopathy, a severe vitamin B1 deficiency disorder, in patients taking GLP-1 drugs for weight loss or diabetes. The cases, reported between 2023 and 2024, were primarily associated with gastrointestinal side effects such as vomiting, diarrhea and loss of appetite, which can impair thiamine intake.
The condition, which can cause permanent memory loss, was most frequently linked to semaglutide-based products like Ozempic and Wegovy, and tirzepatide-based drugs such as Zepbound. Researchers cautioned that the data do not establish a causal relationship, and they emphasized that the findings should not lead patients to discontinue prescribed therapy.
"Researchers went through adverse event reports and the medical literature and found a small number of cases, 15, of Wernicke encephalopathy in people taking GLP-1 drugs," said Karthik Achari, a Chicago-based clinician not involved in the study. "That's out of millions of people on these medications. So this is rare. But it's real, it's serious, and the mechanism makes sense."
The authors noted that immediate treatment is essential to prevent severe outcomes. They called for additional research to clarify the risk, especially for patients experiencing pronounced gastrointestinal symptoms. Drug manufacturers Novo Nordisk and Eli Lilly were contacted for comment but had not responded at the time of publication.