Hydrolyzed Keratin
HY-droh-lyzd KAIR-ah-tin
What Is Hydrolyzed Keratin?
Protein derived from animal keratin (typically sheep wool or feathers) that has been broken down for hair penetration. It repairs and strengthens hair by replenishing its natural protein structure.
Source: Sheep wool, feathers, or hooves (hydrolyzed)
Origin: Natural
Also known as: Keratin Protein, Keratin Amino Acids
What Does Hydrolyzed Keratin Do to Your Hair?
Penetrates damaged areas of the hair shaft to fill in gaps in the keratin structure, restoring strength and elasticity. Repairs chemical and heat damage at the molecular level. Reduces breakage and improves hair resilience.
Best For
Damaged hair, chemically treated hair, heat-damaged hair, breaking hair, high porosity hair
Not Recommended For
Protein-sensitive hair, low porosity hair, fine hair (in excess)
Concentration Matters
0.5-5% in hair products
Hair Type Compatibility
Method Compatibility
Safety & Regulation
Safe for cosmetic use with strong evidence of effectiveness. Can cause protein overload in protein-sensitive hair, leading to stiffness and breakage. Use in moderation and balance with moisture treatments.
FDA Status: Generally Recognized As Safe
FDA permits use in cosmetics without restrictions.
EWG Score: 1/10
HairAide Verdict
The most directly relevant protein for hair repair since hair is made of keratin. Delivers real results for damaged hair. Be careful not to overdo it as protein overload is a real concern, especially for fine hair.
Products That Contain Hydrolyzed Keratin
Protein treatments, bond repair products, conditioners, hair masks, strengthening shampoos
Alternatives to Hydrolyzed Keratin
If you want to avoid Hydrolyzed Keratin, look for products with these ingredients instead:
Hydrolyzed Silk, Hydrolyzed Rice Protein, Amino Acids
Frequently Asked Questions
Yes, Hydrolyzed Keratin has a safety rating of 8/10 and is generally considered safe for use in hair products. Safe for cosmetic use with strong evidence of effectiveness. Can cause protein overload in protein-sensitive hair, leading to stiffness and breakage. Use in moderation and balance with moisture treatments.
Hydrolyzed Keratin is not CG-method approved. Curly hair types may want to avoid this ingredient or use products containing it sparingly.
No, Hydrolyzed Keratin is not approved for the Curly Girl method.
Some alternatives to Hydrolyzed Keratin include: Hydrolyzed Silk, Hydrolyzed Rice Protein, Amino Acids
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