Ingredient · Surface Film and Hair Protein
Hydrolysed Keratin
INCI · Hydrolyzed Keratin
Related names and forms: Keratin Amino Acids. This list does not indicate synonyms or exact ingredient matches.
Hydrolysed keratin (INCI: Hydrolyzed Keratin) is keratin, the natural structural protein of hair and nails, broken down enzymatically or chemically into a mixture of small peptides and amino acids. Hydrolysis breaks the large protein into pieces small enough to adhere to the strand surface. Its actual cosmetic role is largely superficial: a thin film on the cuticle gives smoothness, temporary body and a better-conditioned appearance, and may soften visible frizz through reduced static. The most common misunderstanding is that keratin permanently repairs or rebuilds hair. In a cosmetic product, hydrolysed keratin's effects remain at the level of surface film and feel; it does not permanently reconstruct the inner cortex. This does not make it non-functional: it is useful for surface smoothness, temporary body and feel in damaged hair, particularly colour-treated or heat-exposed hair. By definition it is a protein and peptide mixture of variable molecular weight, not equivalent to one small-molecule CID record; its reference framework uses general source families. Klaris considers the distance between its actual surface role and marketing narrative alongside the formula's moisture-protein balance.
i. Cosmetic Functions
Frequently Discussed Effects
The following headings summarise areas of effect frequently discussed in the literature; visible results in each area require regular use and a suitable formula.
Surface Film
Leaves a thin film on the strand surface, the cuticle, for smoothness and temporary body.
Antistatic and Frizz Appearance
May soften the appearance of frizz by reducing static at the strand surface.
Damaged Hair Context
Often used for surface smoothness and feel in hair damaged by colour, heat or processing.
Mechanism
What Happens Within the Skin?
The following points summarise mechanisms from dermocosmetic literature in plain English. Klaris presents them as background information to help readers understand the context, not as medical claims.
Step 1
Broken-Down Keratin Protein
Natural keratin broken into small peptide and amino acid fragments; their small size helps them adhere to the strand surface.
Step 2
Surface Film and Temporary Body
A thin film on the strand gives smoothness and temporary body. Effects remain at the surface, without permanently rebuilding the internal structure.
Step 3
Antistatic Properties
Contributing to charge balance at the strand surface may soften static and the appearance of frizz.
ii. Role in the Formula
How Is It Read on a Label?
Its low-molecular-weight peptides adhere to the strand and form a thin film, with some settling superficially along the cuticle. Effects are largely surface-level: smoothness, temporary body and feel, not permanent reconstruction of the hair's internal structure. It appears in shampoos, conditioners, masks and leave-ins and is assessed in balance with humectants and emollients.
Typical Concentration Range
0.5% - 5% (depending on formula context)
Ingredient Family
Proteins
iii. Sensitivity Advisory
A Note on Extra Care in Context
Hydrolysed keratin is generally well tolerated. Layering many protein products without moisture balance can make some hair feel stiff; considering moisture and protein balance together is measured.
A sensitivity advisory is not an instruction for use; where individual health circumstances, pregnancy or known sensitivities are involved, discussing the decision with your doctor may be a more contextual approach.
Scientific Basis
Sources and Their Scope
The following headings indicate areas of research; they are not citations of a specific publication or confirmation that every statement on this page has been verified. The links provided should be read with their individual scope in mind.
- International INCI / CosIng database
- Dermocosmetic research publications
- Formulation chemistry guides
Starting Points for Independent Research
These links lead to official databases and serve as starting points for searches.
iv. Related Ingredients
Ingredients Often Read Together
v. Proteins Family
Other Ingredients in the Same Family
Explore ingredients in the same functional family to deepen your reading of formulas.
vi. Academy · Related Reading
For a Closer Look
6 Min Read
How to Read an INCI List on a Hair Product
Familiar ingredient families in shampoo, conditioner and masks, and how the context of the same list changes with your Hair Identity.
6 Min Read
Colour-Treated Hair: How to Read the Ingredients
Colouring changes hair's porosity and moisture balance: key ingredient families, colour-fading tendencies and the context of sulphates and heat.
6 Min Read
Fine and Thick Hair: How to Read the Ingredients
Strand thickness, tolerance for weight and the appearance of volume: key ingredient families for fine and thick strands.
vii. Related Concern Guides
Guides That Include This Ingredient
Klaris · Example Analyses
How Does Hydrolysed Keratin Feature
in Your Products?
Explore product examples to see the ingredient list, general assessment and match score that changes with the example profile together.
Masked products and example profiles, not a personal analysis. Profile matching in the app is part of Klaris Premium. The app is currently available in Turkish. An English version is in preparation.