For decades, medications for obesity typically delivered only modest reductions in body weight. That changed with the arrival of Ozempic and other GLP-1 therapies, which can produce sustained weight loss of 10 to 15% or more. Yet despite their remarkable effectiveness, scientists still do not fully understand what these medications are doing inside the brain.
New research from Yale has now uncovered an unexpected mechanism that challenges a long-standing view of the brain circuits involved in hunger and weight control. Scientists had generally thought that agouti-related peptide (AgRP) neurons, which are well known for stimulating hunger, worked mainly against weight loss. The new findings suggest something very different. During treatment with GLP-1 drugs such as Ozempic, these neurons appear to be recruited to help maintain fat loss.
"This completely changes how we think about the mechanism involved in these medications and provides new insight into the biology underlying their long-term effects, opening an avenue for the development of more efficient drugs," said Mateus d'Ávila, a Ph.D. candidate in neuroscience working in Tamas Horvath's lab in the Department of Comparative Medicine at Yale School of Medicine (YSM) and first author of the study.
