The skin over a mouse’s shoulders warmed up after a dozen days on tirzepatide. That heat map, taken with an infrared camera, pointed to a familiar patch of tissue between the shoulder blades: brown fat, the body’s calorie-burning depot. In a new mouse study, tirzepatide did what many people already associate it with. It drove weight down mainly by cutting appetite. But the work also suggests something else is happening at the tissue level. Even when the researchers matched food intake between groups, tirzepatide pushed brown fat toward a more active, energy-burning state. There were improvements in blood sugar control that food restriction alone did not fully explain. The research team. From left to right, Albert Mestres, Tania Quesada, Albert Blasco, Marta Giralt, Francesc Villarroya, Anna Planavila and Marion Peyrou. (CREDIT: University of Barcelona) A drug built to hit two targets Tirzepatide, sold as Mounjaro, is approved for weight control in adults with obesity or overweight with comorbidities, and for treatment of poorly controlled type 2 diabetes mellitus. Unlike earlier obesity drugs that focus on …