Proteolytic activity of cosmetic enzyme peel products

Our goal was to verify the proteolytic mode of action and activity levels among several commercial cosmetic facial peels advertised by manufacturers as "enzymatic". Eleven enzyme peels were analyzed for their proteolytic activity against casein as a generic substrate and compared to the activity found in pineapple and papaya fruits. The highest specific protease activity was observed in the flesh of a pineapple (5.88 U/g). Only two products demonstrated sufficient activity (0.924 and 0.238 U/g) to be called "enzyme peels". Three products showed trace activity (0.023-0.125 U/g), albeit too low to exert a significant exfoliating effect. Six preparations had no detectable enzyme activity.