What Is Lactoperoxidase?
Lactoperoxidase is an enzyme that naturally occurs in milk, where it helps protect the milk from harmful bacteria by using hydrogen peroxide to break down unwanted substances. Chemically, it belongs to the peroxidase family and contains a heme group, which is an iron based structure that lets the enzyme carry out its protective reactions. For cosmetic use the enzyme can be sourced from purified bovine milk or produced through controlled fermentation, a lab process that lets manufacturers create the same protein without relying on large amounts of animal material.
The cosmetic world first took notice of lactoperoxidase in the 1960s when researchers explored its preservative power in dairy. Over time formulators realized the enzyme could also help keep light sensitive ingredients stable, a property that has grown more valuable as products pack in delicate vitamins, plant extracts and modern actives.
Commercial production starts with culturing microorganisms that have been given the gene for lactoperoxidase. After fermentation the mixture is filtered, purified and dried into a stable powder that can be easily blended into creams and liquids. This biotech route delivers consistent quality while limiting the risk of impurities.
You will most often find lactoperoxidase in products like daily moisturizers, anti aging serums, sheet and rinse off masks, eye creams and leave on treatments geared toward sensitive or redness prone skin. It is also a handy addition to sunscreens and natural themed formulas that avoid strong synthetic stabilizers.
Lactoperoxidase’s Cosmetic Benefits/Uses
In skincare formulas lactoperoxidase serves one primary role that benefits both the product and the user.
Light Stabilizer: The enzyme helps protect other ingredients from breaking down when exposed to light. By minimizing photo degradation it keeps the color, scent and performance of a cream or serum consistent throughout its shelf life. This means the active ingredients you paid for stay potent longer, the texture stays smooth and the product is less likely to develop off odors or lose effectiveness before you finish the bottle.
Who Can Use Lactoperoxidase
Lactoperoxidase is generally considered friendly for all skin types including oily, combination, normal and dry skin because it is used at very low levels and is non comedogenic. Sensitive or redness prone skin usually tolerates it well since the enzyme is not an irritant on its own. Those with a known dairy allergy should check with a professional before use as the ingredient is originally sourced from milk even though the final enzyme is highly purified.
Vegans and vegetarians may need to verify the source. Some suppliers produce lactoperoxidase through fermentation with no animal derived material while others still rely on bovine milk. Brands that label the product as vegan typically use the fermentation route so checking for that claim or asking the company can clear up any confusion.
Current data shows no specific concerns for pregnant or breastfeeding users when the enzyme is applied topically at cosmetic levels. Because research in this group is limited it is best to consult a doctor before adding any new product during pregnancy or nursing. This is not medical advice and individual guidance from a healthcare provider is recommended.
Lactoperoxidase does not make skin more sensitive to sunlight so there is no added risk of photosensitivity. It also plays well with common active ingredients and preservatives meaning it fits into most routines without conflict.
Potential Side Effects/Adverse Reactions
Responses to topical lactoperoxidase vary from person to person. The points below list potential side effects but most users will not experience them when the ingredient is correctly formulated and used as directed.
- Mild redness or irritation in very sensitive skin, usually temporary and limited to the application area
- Contact dermatitis in rare cases where an individual has a specific allergy to milk proteins or to the enzyme itself
- Stinging or tingling if applied to broken or compromised skin barriers
If you notice persistent discomfort stop using the product and consult a healthcare professional for advice.
Comedogenic Rating
Rating: 0 / 5
Lactoperoxidase is a water soluble enzyme used at very low percentages, so it sits on the skin without leaving an oily film that might clog pores. It does not add heavy waxes or fatty acids to a formula, which is why it earns a solid zero on the comedogenic scale.
Because of this, the ingredient is generally fine for people who break out easily and for those with acne prone skin. Formulation factors such as the overall oil content of the product will matter more than the presence of lactoperoxidase itself.
Worth noting: some formulas blend the enzyme with creamy or oil rich bases to improve texture, so always consider the full ingredient list when assessing pore clogging risk.
Summary
Lactoperoxidase is used in cosmetics as a light stabilizer that keeps delicate actives and colorants from breaking down when exposed to daylight. By converting small traces of hydrogen peroxide, the enzyme helps neutralize free radicals created by light, which in turn preserves the look and performance of the product.
While it offers a smart solution for protecting modern formulas, lactoperoxidase is still a niche ingredient compared with big name antioxidants like vitamin C or E. You will mostly spot it in higher end or clean beauty lines that aim for gentle preservation without heavy synthetic additives.
Current safety data rates topical lactoperoxidase as low risk for irritation or allergy in the general population. Still, every skin is unique, so it is wise to patch test any new product that contains this enzyme before full use.