Ingredient review
Keratinase
INCI: Keratinase
Keratinase is a gentle enzyme exfoliant that targets dead skin cells and rough skin without harsh scrubbing.
In plain English
Keratinase is an enzyme that breaks down keratin, the protein that makes up the outer layer of your skin and hair. In skincare, it helps gently remove dead skin cells, smooth rough patches, and soften calluses. Unlike physical scrubs or strong acids, it works by dissolving the bonds between dead cells, so they slough off naturally. It's often used in exfoliating serums, foot peels, and hair removal products to make skin feel smoother and look more even.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- biotech
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Keratinase is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Keratinase.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
Keratinase is a type of enzyme produced by certain bacteria and fungi that specifically breaks down keratin protein. In cosmetics, it is produced via biotechnology for use as a gentle exfoliant.
How it works
Keratinase works by cleaving the peptide bonds in keratin, the structural protein in the outermost layer of skin (stratum corneum). This loosens and dissolves dead skin cells, allowing them to be rinsed away, revealing fresher, smoother skin underneath.
Pros
Gentle exfoliation
Keratinase dissolves dead skin cells without the friction of scrubs or the sting of acids, making it suitable for sensitive areas like feet or elbows.
Targeted action
It specifically breaks down keratin, so it works on rough, thickened skin without affecting healthy skin cells.
Cons and cautions
pH sensitivity
Keratinase works best at a specific pH range (usually around 5-8), so product formulation matters. If the pH is off, it may not work effectively.
Potential irritation with overuse
Leaving keratinase on the skin for too long or using it too frequently can cause mild redness or irritation, especially on sensitive skin.
Best for
- People with rough, dry, or calloused skin
- Those seeking gentle exfoliation without acids or scrubs
Use caution if
- Individuals with open wounds or active skin infections
Usage tips
Safety summary
Keratinase is considered safe for topical cosmetic use at typical concentrations. Mild irritation is possible with prolonged contact or on compromised skin. Avoid contact with eyes and open wounds.
Research notes
Studies show keratinase effectively degrades keratin in the stratum corneum, leading to exfoliation. Research is moderate, with most evidence coming from dermatological and cosmetic science journals.
Common label clues
- Typical concentration
- 0.1% to 1% in leave-on products
- Regulatory status
- Approved for cosmetic use in the EU and US. Not a drug ingredient; regulated as a cosmetic exfoliant.
- Common uses
- Exfoliating serums, Hair removal creams, Anti-aging treatments
- Environmental note
- Keratinase is produced via fermentation using microorganisms, which is generally considered more sustainable than animal-derived enzymes.
Good to know
- Keratinase is often used in foot peels and callus removers because it softens thick skin without cutting.
- It is also used in some hair removal creams to weaken hair keratin for easier removal.
Common questions
What is Keratinase in beauty products?
Keratinase is an enzyme that breaks down keratin, the protein that makes up the outer layer of your skin and hair. In skincare, it helps gently remove dead skin cells, smooth rough patches, and soften calluses. Unlike physical scrubs or strong acids, it works by dissolving the bonds between dead cells, so they slough off naturally. It's often used in exfoliating serums, foot peels, and hair removal products to make skin feel smoother and look more even.
What does Keratinase do in a beauty product?
Keratinase works by cleaving the peptide bonds in keratin, the structural protein in the outermost layer of skin (stratum corneum). This loosens and dissolves dead skin cells, allowing them to be rinsed away, revealing fresher, smoother skin underneath.
Is Keratinase safe for most people?
Keratinase is considered safe for topical cosmetic use at typical concentrations. Mild irritation is possible with prolonged contact or on compromised skin. Avoid contact with eyes and open wounds.
Who should be careful with Keratinase?
Individuals with open wounds or active skin infections
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.