Pepsin

Table of Contents

Other names

Gastric Pepsin
Stomach Protease
Porcine Pepsin

Synopsis

Pepsin is a proteolytic enzyme (protein-digesting enzyme) produced naturally in the stomach lining as an inactive precursor called pepsinogen, which becomes activated in the presence of gastric acid. It is one of the primary enzymes responsible for breaking down proteins into peptides during digestion. In supplement form, pepsin is typically derived from porcine (pig) gastric mucosa and is often combined with hydrochloric acid (HCl) or betaine HCl to mimic natural stomach acid conditions and aid digestion.

Medicinally, pepsin is used in individuals with low stomach acid (hypochlorhydria) or digestive insufficiency, where the body produces insufficient acid or enzymes to properly break down proteins. This condition can lead to bloating, indigestion, nutrient malabsorption, and food sensitivities. Pepsin supplements help restore digestive function, particularly in older adults or those with chronic stress, autoimmune disorders, or long-term use of antacids and proton pump inhibitors (PPIs).

Pepsin is also sometimes used in digestive enzyme blends for post-surgical recovery, chronic pancreatitis, or convalescence where protein intake needs to be optimized. In addition to supporting digestion, pepsin assists in the absorption of amino acids, vitamin B12, and minerals like iron and zinc, which depend on adequate stomach acid and enzyme activity.

Historical Use in Medicine
Pepsin was first discovered and named in 1836 by Theodor Schwann, a pioneering German physiologist who identified it as one of the earliest enzymes recognized by science. Its discovery marked a major milestone in understanding chemical digestion, and it became one of the first enzymes to be commercially extracted and used therapeutically.

By the late 19th and early 20th centuries, pepsin became a staple in Western pharmacology, included in over-the-counter digestive tonics, bitters, and “pepsin wines”—popular remedies used for dyspepsia, gastric weakness, and convalescence. It was frequently prescribed by physicians for patients recovering from illness or dealing with chronic indigestion.

In early natural and naturopathic traditions, pepsin was included in formulations designed to stimulate digestion, often paired with gentian, ginger, or bile salts to restore gastric function and appetite. It was particularly valued for the elderly, weak, or those recovering from fever or wasting illnesses, where restoring protein digestion was vital.

Uses: Health Conditions

None

Body Systems

Digestive System (Science)
Gastrointestinal Tract (Science)
Stomach (Science)