GLP-1-driven vitamin deficiency linked to rare brain disorder: Study

( NewsNation ) — A new study found that a rare but serious brain condition has been identified in a small number of people taking popular weight-loss drugs such as Ozempic, Wegovy, Mounjaro and Zepbound.

Wernicke encephalopathy is a rare neurological disorder caused by a severe deficiency of vitamin B1, also known as thiamine.

Researchers identified 15 cases reported in 2023 and 2024 among people taking GLP-1 medications containing semaglutide, found in Ozempic and Wegovy, or tirzepatide, found in Mounjaro and Zepbound.

Vitamin B1 is essential for proper nerve function. Without enough of it, patients can develop confusion, problems with balance and coordination, and abnormal eye movements.

If left untreated, the condition can lead to permanent brain damage or death. Physicians consider it a medical emergency.

GLP-1 drugs can contribute to vitamin deficiencies by suppressing appetite and reducing food intake, including foods rich in vitamin B1, such as pork, fish and whole grains.

The study found that most patients who developed the condition also experienced severe vomiting, loss of appetite, poor nutrition or rapid weight loss.

While the disorder remains rare, researchers said the findings should help doctors educate patients about the risk and monitor for warning signs.