AHA is an abbreviation of Alpha Hydroxy Acid. Many AHAs are known as Fruit Acids. The complex used in Eucerin Hyaluron-Filler Night Peeling & Serum combines three different acids – Glycolic Acid, Lactic Acid and Gluconolactone (a Polyhydroxy Acid). Lactic Acid is skin’s own natural moisturising factor, and all three are clinically and dermatologically proven to gently but effectively exfoliate skin and stimulate cell renewal. Gluconolactone also supports the matrix around skin collagen, protects against collagen degradation and helps skin to maintain its elasticity.