Ozempic does something unexpected to the brain’s hunger neurons

Decades of obesity medications have only yielded modest weight loss reductions. However, the advent of Ozempic and similar GLP-1 therapies has produced sustained weight loss of 10 to 15% or more. Scientists have not fully comprehended the brain mechanisms behind these medications' effectiveness. A new Yale study reveals an unexpected mechanism that challenges the conventional view of hunger neurons.

Previously, it was believed that agouti-related peptide (AgRP) neurons, which stimulate hunger, primarily worked against weight loss. The new findings suggest the opposite: during treatment with GLP-1 drugs like Ozempic, these neurons are recruited to help maintain fat loss. This paradigm shift in understanding could lead to more efficient drugs for obesity treatment.

The research, published in the journal Proceedings of the National Academy of Sciences (PNAS), was conducted using mouse models and genetic techniques. When mice lacking AgRP neurons were treated with GLP-1 drugs, the weight loss was no longer sustained. The researchers found that rather than being suppressed by semaglutide, AgRP neurons were activated.

The findings indicate that cells traditionally seen as barriers to weight loss may become part of the biological machinery that enables GLP-1 therapies to sustain fat loss. Further research is needed to determine if this mechanism applies to humans, but identifying how GLP-1 medications influence the brain could pave the way for more effective obesity treatments with fewer side effects.