Isoleucine

An essential branched-chain amino acid naturally found in skin and used as a humectant to help retain moisture. It is a recognized component of the natural moisturizing factor with a history of safe use in cosmetics at typical concentrations.

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.