INCI · other · CIR review pending · used in 5 products
Leucine
Leucine is an essential branched-chain amino acid (BCAA) used in cosmetic formulations. It is found naturally in proteins and is included in skincare and haircare products as part of amino acid complexes. The source page lists it as an ingredient across a range of moisturizers, serums, toners, and shampoos.
Evidence level
weakEWG score
—Comedogenic
—Category
other● Benefits
As an amino acid, leucine is understood to support the skin's natural moisturizing factor (NMF) and may contribute to barrier function. It is commonly used in formulations targeting hydration and conditioning of skin and hair.
hydratingbarrier-support
● Cautions
