GLP-1’S AND WERNICKE ENCEPHALOPATHY, WERNICKE-KORSAKOFF SYNDROME

Wernicke-Korsakoff Syndrome is an organic brain disorder that is usually a late sequela of chronic alcoholism. It is a degenerative disease of the brain, and occurs when the brain has been subjected to repeated assault by alcohol and/or severe deficiency of thiamine, or vitamin B1. Thiamine converts food into energy and is protective of the brain and spinal cord tissues. Alcoholics and GLP-1 users are both prone to have a deficiency of thiamine because alcoholism and weight loss both reduce thiamine stores through severe restriction of dietary intake. Alcoholics drink alcohol and frequently skip meals, and thus develop thiamine deficiency. GLP-1’s users find they are eating significantly less food, especially those containing thiamine, so they become deficient, as well.  

There was a recent report in Obesity of 6 middle-aged adults in their 40’s who after taking semaglutide for nearly 5 months developed loss of appetite, weakness, nausea, vomiting, and constipation followed by mental status changes (confusion, memory loss, decreased alertness), involuntary eye movements called nystagmus, and unsteady, or ataxic, gait. MRI images then showed changes consistent with Wernicke’s encephalopathy. The diagnosis was conclusively made later at postmortem autopsy study. 

This is a disturbing result of taking the GLP-1, semaglutide. Although there were only 6 patients, they all had significant co-morbidities, and one of them died. Four of the other five were left with permanent memory impairment and crossed over to the more serious and chronic Wernicke-Korsakoff syndrome. The concern is that more cases of this encephalopathy may occur. So far, there has been no indication that it couldn’t happen more often. 

So doctors are being warned to be on the alert for mental status changes in GLP-1 users and to be certain they have an adequate intake of vitamins and minerals, and protein. Developing this encephalopathy, which is potentially irreversible, can make for a very unpleasant life. 

Reference: Bhattacharya S. Semaglutide Linked to Rare Brain Illness Medscape.com;2026 July 14.