pepsinogen

Pepsinogen is the inactive precursor to pepsin, a powerful enzyme found in gastric juice that digests proteins. Pepsinogen is produced by glands in the stomach lining and is released into the stomach when stimulated by nerve impulses and hormones like gastrin and secretin. In the acidic environment of the stomach, mixed with hydrochloric acid, pepsinogen is rapidly converted into its active form, pepsin.12

Pepsin is most effective at a pH between 1.5 and 2.5. It breaks down proteins into smaller units called peptides, which are then further processed in the intestine. Pepsin also plays a role in certain health conditions, such as gastroesophageal reflux disease and peptic ulcer disease, due to its presence in stomach acid.1