Lactose is a disaccharide composed of galactose and glucose molecules. Fresh milk contains around 3–7% lactose thus this sugar got its name from "lactis" (means milk in Latin). This natural saccharide has beneficial properties for the skin and is used in many skincare products.
Lactose is good probiotic as it's a nutrient for Lactobacillus and Bifidobacteria. Meanwhile, the majority of harmful bacteria and yeast unable to hydrolyze (into galactose and glucose) and consume it. It changes and improves skin microbiota balance providing a healthy, youthful, and refreshed appearance.
Lactobacillus consumes lactose and produces Lactic acid, which is a natural moisturizing factor (NMF) an alpha-hydroxy acid (AHA) that eliminates dead or dull cells from the surface of the skin and enhances the renewal rate revealing a fresh and radiant complexion.
This multifunctional disaccharide also has water-binding property. It stimulates skin hydration providing volume and elasticity and smoothing fine lines and wrinkles.