What it is
Leucine is one of the standard amino acids found in proteins and is used in cosmetics as a conditioning ingredient. In powders and some emulsions, including sunscreen powders, it can also improve adhesion and impart a soft, smooth feel. It is typically used at low concentrations.
Safety & warnings
Leucine is generally well tolerated in topical use and is not a common sensitizer. As with any cosmetic ingredient, finished-product tolerability depends on the overall formulation.
Origin & sourcing
Naturally occurring amino acid; the cosmetic-grade material is generally produced by fermentation or synthesis.
Questions everyone asks
What is leucine used for in cosmetics?
It is an amino acid used as a conditioning agent and, in powders, to improve adhesion and a soft feel.
Is leucine safe on skin?
It is a common amino acid that is generally well tolerated in topical products at the levels used.