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Hair Conditioning

CYSTINE

CAS 56-89-3
85

Safety score · 0–100

Good

Derived from EU CosIng regulatory status, PubChem hazard data and published research. How we score.

A natural amino acid (two cysteines linked by a disulfide bond) — a building block of keratin. Excellent safety record at cosmetic levels.

Function

ANTISTATIC, HAIR CONDITIONING, FRAGRANCE

Skin benefits

  • Sulfur-containing amino acid
  • Hair structure component
  • Skin/hair conditioning

Known concerns

  • No significant concerns at cosmetic concentrations
  • Mild rare allergy possible

References

EU

EU CosIng database

European Commission cosmetic ingredient registry: regulatory status, restrictions, authorised functions.

Related hair conditionings

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DIMETHYL CYSTINATE
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GLYCERYL HYDROXYSTEARATE/OLEATE ESTERS
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METHOXY AMODIMETHICONE/SILSESQUIOXANE COPOLYMER
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PALMITOYL TETRAPEPTIDE-132 OLIGOPEPTIDE-258 AMIDE
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POLYSILICONE-18 STEARATE
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SH-DECAPEPTIDE-13
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 84
DISODIUM AMODIMETHICONE DISUCCINAMIDE
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 84
ETHYL BIOTINATE
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This profile is for educational purposes and does not constitute medical advice. Regulatory status and scientific understanding evolve, so always read the physical product label and consult a healthcare professional for personal concerns.