High‑dose GLP‑1 drugs like semaglutide and tirzepatide can cause severe thiamine deficiency (Wernicke encephalopathy) if they make you vomit or eat far less, especially with rapid weight loss. The study found this risk shows up more often than expected, so you should watch for persistent nausea, keep your food intake adequate, and consider thiamine supplements if you’re on these meds.

Although GLP-1 receptors analogues (RAs) benefits-risks profile has been largely documented in diabetes, higher dosages recently approved in obesity still require further assessment. We describe here the case of a 49-year-old female patient treated with semaglutide for obesity, who presented with Wernicke encephalopathy in a context of iterative vomiting and reduced food intake. Eighteen other cases of Wernicke encephalopathy were reported in literature and in the WHO global safety database (VigiBase). A context of nausea/vomiting or reduced food intake is described in 68% of cases, with weight loss ranging from -3.5 to -13.3 kg/month over 3 to 6 months. Disproportionality analysis in VigiBase showed that Wernicke encephalopathy was disproportionately reported with semaglutide, tirzepatide and the whole GLP-1RAs group. Altogether, this comprehensive analysis supports a safety signal regarding the risk of Wernicke encephalopathy with GLP-1RAs, which requires a prompt assessment, accounting for the growing use of these drugs.