Pepsin

CAS 9001-75-6

Pepsin is a protein-digesting enzyme used in cheesemaking, often blended with rennet, and in producing protein hydrolysates. It is obtained from the stomachs of pigs and cattle.

Where it is and isn’t permitted

Status of Pepsin by jurisdiction. Every jurisdiction this site covers is listed, including those where the substance does not appear.
JurisdictionStatusScope and limitsCitation
United StatesFood and Drug AdministrationPermitted21 CFR 184.1595retrieved 2026-09-07
Codex AlimentariusCodex Alimentarius Commission / JECFANot listedDoes not appear on this jurisdiction’s permitted list. That is not the same as being prohibited.

What it is made from

Extracted from the glandular layer of porcine or bovine stomachs. The porcine source is why pepsin raises a specific concern under halal and kosher rules beyond the general question of animal derivation.

  • Not vegan
  • Not vegetarian
  • May raise a halal question
  • May raise a kosher question
CAS registry number
9001-75-6

Every name it appears under

2 recorded names. A label may use any of them.

CAS registry number

  • 9001-75-6

As it appears in regulation

  • Pepsin

Hazard reference values

No reference value for this substance in the sources we hold.

Evidence and how bodies read it

Studies, and the differing conclusions regulators drew from them, are curated by hand rather than machine-read, and none has been written for this substance yet.

Sources for this page

  • ecfr retrieved 2026-09-07

Full licence terms and publisher details on Sources. How this page is built and updated: Method.

Machine-readable:/api/v1/additives/pepsin.json