What makes GLP1 receptor agonist drugs so effective for obesity?

What makes GLP1 receptor agonist drugs so effective for obesity? Michael W. Schwartz, MD, discusses the effectiveness of GLP1 receptor agonist drugs, such as semaglutide and tirzepatide, in treating obesity as well as the role of gut-brain signaling in maintaining energy homeostasis. Over the past decade, the treatment of obesity and its closely related metabolic disorder, type 2 diabetes (T2D), has been revolutionized by the introduction of so-called GLP1 receptor agonist drugs. These drugs, which include semaglutide and tirzepatide, work by activating GLP1 receptors distributed throughout the body. While some of their effects involve peripheral tissues, the brain is the primary target for their anti-obesity action. Of particular importance are neurons that express the GLP1 receptor and are located in two key hindbrain areas: the area postrema (AP) and the nucleus of the solitary tract (NTS).