Scientists may have discovered why GLP-1 weight-loss drugs eventually plateau — and how to make them work longer. Credit: Shutterstock Researchers at the National Institutes of Health (NIH) have uncovered new details about how GLP-1 weight loss drugs such as semaglutide affect brain cells, revealing internal signaling processes that scientists have only begun to understand. The findings, based on experiments in mice, shed light on why these medications work differently from person to person and