INCI: Silk Amino Acids | Function: Moisturizer, Film Former, Conditioning | Type: Hydrolyzed protein (amino acid blend)
What Is Silk Amino Acids?
Silk Amino Acids are obtained by complete hydrolysis of natural silk fibroin. They are a blend of 18 amino acids, primarily glycine, alanine, and serine. In skincare, they provide excellent moisture-binding, form a protective film, and impart a luxurious silky feel. Also used in hair care for shine and conditioning.
Key Skin Benefits
+ Excellent moisture-binding (amino acids are NMF components)
+ Forms protective, breathable film on skin/hair
+ Imparts silky, smooth after-feel
+ Small molecular size allows some penetration
+ Adds shine and manageability to hair
Pros
+ Natural-derived from silk protein
+ Full spectrum of 18 amino acids
+ Lightweight, non-greasy conditioning
+ Good film-forming and moisture retention
+ Works in both skin and hair care
Cons
− Animal-derived (not vegan — silk worms)
− May not suit those avoiding animal ingredients
− Some grades can be sticky
− Scent can vary between suppliers
− Less potent than synthetic peptides for anti-aging
Specifications
Property
Value
Usage Areas
Face, Eye, Body, Hair
Product Type
Leave-On, Rinse-Off
Source
Animal (silk) / Biotech
Natural Level
Natural
Safety Ratings
Metric
Rating
Skin Sensitivity
0/5 (none)
Comedogenic Rating
0/5
EWG Score
1/10
Regional Regulatory Limits
Region
Leave-on %
Rinse-off %
Status
EU (CosIng)
No limit
No limit
Allowed
US (CIR/FDA)
No limit
No limit
Allowed
Japan (MHLW)
No limit
No limit
Allowed
ASEAN
No limit
No limit
Allowed
China (NMPA)
No limit
No limit
Allowed
Typical Usage % by Product Type
Product Type
Typical %
Moisturizer / Serum
0.1 - 2%
Hair conditioner / mask
0.5 - 3%
Toner
0.1 - 1%
References
Aramwit P et al. (2012) — Silk sericin applications in cosmetics. PMID: 23135778