In a blind subjective test, 10 panelists were asked to apply formulations containing either 5.6% Glycolic Acid (at pH 4.0) or 5.6% L-Carnitine (pH 7.0) to an area immediately beneath the eyes, and then to indicate at which site (if any) they experienced a stinging sensation. It showed that L-Carnitine based formulation was rated by the panelists to be superior to the Glycolic Acid based formulation in terms of sting.