How can the peptide CCK be effective for weight loss?

One of the most promising drug therapies involves the injection of the peptide CCK (cholecystokinin, or what I like to call the Crucial Cravings-Killer peptide) or things that have a chemical structure similar to CCK.

CCK causes your stomach to hold onto food for a long time, and sends messages to the brain to say you're full. The body produces specific enzymes in the small intestine to degrade CCK, but new developments show that you can stop that action. Ingesting or inhaling CCK that can access the bloodstream may help increase satiety levels.