thickener
Polyquaternium-51
Generally safe·Moderate evidence
A positively charged conditioning polymer used in hair and skin products to improve texture and feel. It is graded safe by CIR and has a low incidence of reported sensitivities at typical use levels.
References
Cosmetic information for general education, not medical advice. A verdict is a reading of the published evidence, never a guarantee for your skin: any ingredient can irritate someone, so patch test new products and see a professional if you react. Concern is graded on cited evidence, never on hazard-score lists. See how we score.