Lancet 397(10271):293304
Robert Kushner: Well, the BMI classifications, the cut points you mentioned, have actually now been removed by the FDA for semaglutide and the other drug called tirzepatide, the two major drugs on the market
Endocrinology, 134, 21562164
GLP-1 receptor agonists slow gastric emptying and suppress appetite, which can reduce energy intake and cause fatigue Fatigue is most common during initial weeks and dose increases, often improving as the body adapts over several weeks to months Nutritional deficiencies in protein, iron, vitamin D, and B vitamins may develop when food intake drops significantly Optimising nutrition with nutrient-dense foods, maintaining hydration, and gentle physical activity can significantly reduce tiredness Contact your GP if fatigue is severe, worsening, or accompanied by signs of dehydration, hypoglycaemia, or persistent gastrointestinal symptoms Table of Contents Why GLP-1 Medications Can Cause Tiredness Glucagon-like peptide-1 (GLP-1) receptor agonists are increasingly prescribed medications for type 2 diabetes and weight management, including semaglutide (Ozempic, Wegovy) and liraglutide (Victoza, Saxenda)