Semaglutide is a medicine based on GLP-1, a natural protein in your body that helps lower blood sugar and increase insulin production. Studies suggest it may also protect the heart, liver, and lungs, and could even help slow or prevent Alzheimer’s disease. One of its main effects is reducing hunger by slowing how quickly your stomach empties food and how fast your intestines move. It works by helping your body release insulin and lower blood sugar, but only when your blood sugar is too high.