Common Name(s): Dodecyl pg-aminoethyl disulfide keratin,keratin protein hair bond repair,disulfide cross-linking active
CAS Number: N/a
DESCRIPTION
What It Does: Forms new disulfide bonds with the exposed free thiol groups of bleach-damaged hair keratin — rebuilding the broken protein crosslinks that cause brittleness, not just masking the damage with a conditioning surface film.
Why It's Used: Unlike conventional conditioners that coat hair surface, this ingredient forms covalent disulfide bonds with hair keratin — genuine chemical repair at the protein crosslink level supporting measurable breakage reduction claims.
How It Works: Cationic groups electrostatically deposit the keratin on negatively charged damaged hair cortex. disulfide groups undergo thiol-disulfide exchange with free -sh (from oxidatively broken cystine): r-ss-r' + hs-keratin forms a new covalent r'-s-s-keratin crosslink. this restores the structural integrity of the protein network damaged by bleach, perm, or heat.
Typically Found In: Bond repair treatments,damaged hair,chemical hair care
TECHNICAL DETAILS
Primary Category: Active ingredient – 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: 0.5%–5%
SOURCING & ETHICS
Vegan Status: No - animal-derived
Halal Status: Conditional - halal slaughter certificate required (species declaration and slaughter method)
Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier. [audit 2026-07-29 rev2: name declares rendered fat or animal tissue; halal status depends on species and slaughter, neither of which is in the record. determination requires shariah-panel sign-off.]
SKIN COMPATIBILITY
Irritancy Rating: 1/5 – very low
Comedogenicity Rating: 0/5 – 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: 1–2.
Works Well With: Standard skincare actives
Avoid Combining With: No known significant incompatibilities
SCIENTIFIC NOTE
This ingredient bridges cosmetic conditioning and chemical hair treatment — disulfide bond formation provides genuine chemical hair repair supporting clinical claims of reduced breakage that surface-depositing conditioners cannot substantiate.
Last Verified: 2026-03-12
Primary Sources: Cosing database,keratin disulfide protein hair bond repair review