Protease is not inherently vegan or non-vegan. It’s a type of enzyme that breaks down proteins, and it can come from animal tissues, plants, or microorganisms. Whether a specific protease is vegan depends entirely on its source, and unfortunately, food labels rarely make that clear.
Three Sources of Protease
Protease shows up in food production, supplements, and household products, and the three main sources sit on very different points of the vegan spectrum.
Animal-derived protease comes from the organs of slaughtered animals. The classic examples are pepsin and chymosin (also called rennin), both extracted from the stomach lining of young calves. Traditional cheesemaking relies on this type of protease to coagulate milk. These are clearly not vegan.
Plant-derived protease is extracted from fruits, roots, and other plant tissues. The most common ones include:
- Papain: from papaya latex
- Bromelain: from pineapple stems
- Ficin: from fig latex
- Actinidin: from kiwifruit
- Zingibain: from ginger root
Less common plant proteases have been identified in cashew fruit, cassava root, mango peel, jackfruit leaves, and wild cantaloupe. All plant-derived proteases are vegan.
Microbial protease is produced through fermentation using bacteria or fungi. One of the most widely used is from a fungus called Aspergillus oryzae, which has a long history in Asian food production and carries a “Generally Recognized as Safe” (GRAS) designation from the FDA. Microbial proteases are typically considered vegan since no animals are involved in the process.
Where You’ll Encounter Protease
Protease is far more common in everyday products than most people realize. Meat tenderizer powders are one of the most recognizable uses. These typically contain papain or bromelain, both plant-based. If you’ve ever noticed that fresh pineapple or kiwi makes your mouth tingle, you’ve felt protease at work, breaking down proteins on contact.
In baking, proteases help modify gluten structure in dough. In brewing, they clarify beer. Laundry detergents use protease to break down protein-based stains like blood and grass. These industrial applications overwhelmingly rely on microbial sources because they’re cheaper and easier to produce at scale than animal-derived alternatives.
Digestive enzyme supplements are where things get trickier for vegans. These blends often list “protease” without specifying the source. Some use microbial or plant-derived enzymes, while others use pancreatin, which comes from pig or cow pancreas. You’ll need to check whether the product is specifically labeled as plant-based or vegan-certified.
The Cheese Problem
Cheese is the food category where animal-derived protease matters most to vegans and vegetarians alike. Traditional rennet, the protease mixture used to curdle milk, comes from calf stomachs. Many heritage European cheeses still use it. Parmigiano Reggiano, Stilton, and traditional Comté all rely on animal rennet.
The industry has largely shifted away from this. Roughly 90% of commercially produced cheese in the United States now uses fermentation-produced chymosin, where microorganisms are engineered to produce the same coagulating enzyme without any animal tissue. Microbial rennet, derived from molds, is another alternative. Some cheesemakers use plant-based coagulants instead, like cardoon thistle, which has a long tradition in Spain and Portugal.
If you’re vegan, cheese is off the table regardless of the rennet source since it contains milk. But for vegetarians trying to avoid animal-derived enzymes, this distinction matters. Look for labels that specify “microbial rennet,” “vegetable rennet,” or “non-animal enzymes.”
How to Tell if a Protease Is Vegan
This is the frustrating part. The FDA does not require manufacturers to disclose whether an enzyme comes from an animal, plant, or microbial source. Allergen labeling rules apply only to the eight major food allergens (like milk, wheat, or soy), so if a protease is derived from, say, a calf stomach, there’s no legal obligation to say so on the label. The ingredient list might simply read “enzymes” or “protease.”
Your best options for identifying vegan protease are to look for third-party vegan certifications on the product, check whether the manufacturer specifies the enzyme source on their website, or contact the company directly. Supplements marketed as “plant-based digestive enzymes” will typically use bromelain, papain, or fungal proteases. Products listing “pancreatin” or “pepsin” are animal-derived.
When a product lists only “protease” or “enzymes” with no further detail, the source is genuinely unknowable without contacting the manufacturer. In processed foods and detergents, microbial sources dominate for cost reasons, making them likely vegan. In supplements and artisan cheese, the odds are less predictable.