Cholecystokinin (CCK)

Cholecystokinin, or CCK, is a hormone released by the gut after eating. It signals the brain that you are full, helping to slow digestion and reduce appetite.

Cholecystokinin is a peptide hormone secreted by enteroendocrine cells of the duodenum and jejunum in response to fat and protein. It stimulates gallbladder contraction and pancreatic enzyme secretion and acts as a satiety signal via vagal afferents and the hypothalamus, contributing to meal termination.

Satiety hormones like CCK are part of the complex system that regulates appetite. Understanding them helps explain why medical weight-loss therapies can be more effective than willpower alone.