Ingredient · Surface Film and Silk Protein
Hydrolysed Silk
INCI · Hydrolyzed Silk
Related names and forms: Silk Amino Acids · Serica. This list does not indicate synonyms or exact ingredient matches.
Hydrolysed silk (INCI: Hydrolyzed Silk; some labels show Silk Amino Acids or Serica) is the water-soluble form of protein from silk fibres produced by the silkworm Bombyx mori, particularly fibroin and sericin, broken down enzymatically or chemically into small peptides and amino acids. Hydrolysis makes the large silk protein small enough to adhere to hair and skin surfaces. Its actual cosmetic role is largely superficial: a thin film gives smoothness, slip and softness, plus temporary body and shine in hair. Water binding also contributes to a moist, conditioned surface feel. The most common misunderstanding is that silk protein permanently repairs hair or skin; hydrolysed silk in a cosmetic product acts at the level of surface film and feel. This does not make it non-functional: it is useful for surface smoothness and feel. Silk is an animal-derived protein, so labels can inform vegan preferences. As a peptide mixture of variable molecular weight, hydrolysed silk has no single small-molecule CID record; its reference framework uses general source families. Klaris considers its actual surface role alongside the distance from the marketing narrative.
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 and Smoothness
A thin film on hair or skin provides smoothness, slip and a conditioned feel.
A Moisturised Feel
Its water-binding tendency supports a soft, moist surface feel.
Hair Body and Shine
A film on the strand contributes to temporary body and a shinier appearance.
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 Silk Protein
Silk fibre proteins, fibroin and sericin, broken into small peptides and amino acids; their size helps surface adhesion.
Step 2
Surface Film and Feel
A thin film on hair and skin provides smoothness, slip and a moisturised feel. Effects remain at the surface.
Step 3
Temporary Surface Effects
Gives hair temporary body and shine without permanently changing its internal structure.
ii. Role in the Formula
How Is It Read on a Label?
Hydrolysed silk is the water-soluble form of silk protein broken into low-molecular-weight peptides and amino acids. Their small size helps adhesion to hair and skin surfaces. Haircare shampoos, conditioners, masks and leave-ins use it for smoothness and feel; skincare moisturisers and serums use it for surface feel. Effects are largely superficial and temporary.
Typical Concentration Range
0.5% - 3% (depending on formula context)
Ingredient Family
Proteins
iii. Sensitivity Advisory
A Note on Extra Care in Context
Hydrolysed silk is generally well tolerated. With known animal-protein sensitivity, patch testing a new product is measured. Silk is animal-derived, so labels can inform vegan preferences.
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
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.
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.
vii. Related Concern Guides
Guides That Include This Ingredient
Klaris · Example Analyses
How Does Hydrolysed Silk 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.