Ozempic and Mounjaro: How GLP‑1 and GIP drugs work for diabetes and weight loss

Ozempic (semaglutide) and Mounjaro (tirzepatide) are injectable medicines originally approved for type 2 diabetes. Both mimic the gut hormone GLP‑1; Mounjaro also activates GIP receptors. By stimulating these pathways they increase insulin release when blood glucose rises, suppress glucagon, slow gastric emptying and send strong satiety signals to the brain, often described as reducing "food noise". The combined effects lead to lower appetite, prolonged fullness after small meals and substantial weight loss, with some patients reporting reductions of 15‑20 % of body weight.

Common side effects include nausea, vomiting, diarrhoea, constipation and abdominal fullness, especially when treatment begins or doses are increased. When therapy is stopped, GLP‑1 and GIP activity returns to baseline, appetite rises and the stomach empties at normal speed, so weight can be partially regained unless lasting dietary and exercise changes are adopted. Clinicians advise that the drugs are not standalone solutions but should be part of a supervised, comprehensive weight‑management plan.