Common Name(s): Chitosan,deacetylated chitin biopolymer,cationic film-former
CAS Number: N/a
DESCRIPTION
What It Does: Forms a substantive cationic film on skin and hair through electrostatic attraction to negative surfaces, provides antimicrobial activity against gram-positive bacteria and fungi, and promotes wound healing via keratinocyte and fibroblast stimulation.
Why It's Used: The only natural cationic biopolymer from shellfish providing simultaneous substantive deposition and antimicrobial activity โ preferred over synthetic quats for clean-label hair and skin conditioning.
How It Works: Protonated amine groups (pka ~6.5) in chitosan electrostatically bind hair cuticle and skin corneocytes (net negative charge at ph >5.5), depositing a film that reduces friction and provides conditioning. cationic character disrupts bacterial membranes providing antimicrobial activity.
Typically Found In: Hair conditioning,wound care,film-forming
TECHNICAL DETAILS
Primary Category: Active ingredient โ cosmetic active
Secondary Functions: Skin conditioning
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.1%โ3%
SOURCING & ETHICS
Vegan Status: Conditional - crustacean or fungal route; fungal chitosan is vegan
Halal Status: Conditional - crustacean or fungal route; feedstock declaration required
Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: chitin family; a fungal route exists that is both halal-simpler and vegan, so origin must be declared. determination requires shariah-panel sign-off.]
SKIN COMPATIBILITY
Irritancy Rating: 1/5 โ very low
Comedogenicity Rating: 0/5 โ non-comedogenic
Sensitivity Concerns: Well-tolerated by most skin types.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Good safety profile at recommended concentrations. ewg score: 1โ2.
Works Well With: Standard skincare actives
Avoid Combining With: No known significant incompatibilities
SCIENTIFIC NOTE
Chitosan's partial structural identity with hyaluronic acid (shared n-acetylglucosamine backbone) provides biocompatibility with skin extracellular matrix proteins and partial cross-reactivity with cd44 hyaluronan receptors.
Last Verified: 2026-03-12
Primary Sources: Cosing database,chitosan cationic biopolymer conditioning review