Vast group of protein molecules, produced by all living things, that act as catalysts in chemical and biological reactions. Enzymes are divided into six main categories: oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases. The names of most, but not all, enzymes end in –ase. [1,2]
Enzymes are used in skincare products to facilitate exfoliation. Most enzymes are finicky about how and under what conditions they will act. Sometimes several enzymes are required to carry out a particular chemical reaction, and their actions are affected by temperature and pH. Some enzymes depend on the presence of other enzymes, called coenzymes, to function, or they depend on a specific body temperature. It would require an exceptionally complicated process to stimulate enzyme activity via topical application to skin. 
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- Lods L, Dres C, Johnson C, Scholz D, Brooks G. The future of enzymes in cosmetics. Int J Cosmet Sci. 2000;22(2):85-94.