New weight loss drugs based on semaglutide, marketed under names such as Ozempic, Wegovy, and Rybelsus, are showing both promise and concern. Semaglutide works by mimicking the action of an internal peptide called GLP-1. Scientists have modified the amino acid sequence of GLP-1 to create semaglutide. Our bodies naturally degrade GLP-1 with something called DPP-4. In semaglutide, the peptide is altered so that it cannot be broken down by the body’s natural process of DPP-4. This is why semaglutide will stay active for 7 days in the bloodstream.