What it is
Semaglutide is a synthetic 31-amino-acid peptide that mimics the body's natural glucagon-like peptide-1 (GLP-1). It was developed by Novo Nordisk as a long-acting GLP-1 receptor agonist and approved by the FDA for type 2 diabetes in 2017 (Ozempic), oral diabetes in 2019 (Rybelsus), and chronic weight management in 2021 (Wegovy). It has become one of the most-prescribed and most-studied drugs in the world.
How it works
- 01
Semaglutide binds and activates the GLP-1 receptor, mimicking the action of the native incretin hormone GLP-1 that the gut releases after meals.
- 02
It stimulates glucose-dependent insulin secretion from pancreatic beta cells — meaning it only triggers insulin release when blood sugar is elevated, which is why hypoglycemia risk is low compared to insulin.
- 03
It suppresses glucagon secretion from alpha cells, reducing hepatic glucose output.
- 04
It slows gastric emptying, prolonging satiety after meals. This is the primary mechanism for weight loss.
- 05
Central GLP-1 receptors in the hypothalamus reduce appetite and food reward signaling — a key reason it produces weight loss beyond what gastric slowing alone would predict.