Enzymes and Acids in Skin Care

Skincare products have become increasingly more effective over the years as estheticians and formulators continue to search for the best active ingredients for their client's skin. Two of the most common (and results-oriented) active ingredient categories for exfoliation, used in professional skincare products today, are enzymes and acids.  Understanding the difference between these two components is key in providing effective results for clients.


Enzymes and acids can both be beneficial as exfoliants in skincare. Enzymes are proteins that catalyze biochemical reactions and act as gentle exfoliators for sensitive skin types. They also play an important role in digestion, metabolism, cellular repair, and inflammation. In skin care products, enzymes act as exfoliants to rid the skin of dead skin cells and debris, promoting a smooth and even complexion. Common enzymes used in skin care products are found in cacao seeds, cranberries, and papain from papaya, along with protease, amylase, lipase, and cellulose.
Acids, on the other hand, work by breaking down the bonds between dead skin cells to reveal healthier skin underneath. Both have their place in skin care regimens, and in the treatment room, and estheticians need to understand the differences between them and the intricacies of each specific type of enzyme and acid to provide optimal results for clients. With proper care and attention, enzymes and acids can both be effective treatments for achieving healthier, brighter skin. 

Before applying either exfoliant type to the skin, it is recommended to conduct a proper consultation with each client to be aware of any known allergies a client may have so they can be avoided. Always test-patch the enzyme or acid in a hidden area like behind the ear or behind the neck, prior to a full treatment to make sure the client can tolerate the enzyme or acid. Keep in mind, enzymes and acids can both increase the skin's sensitivity to the sun, therefore it is vital to apply SPF (and reapply often throughout the daytime).

When using enzymes in skin care products, estheticians must be mindful of the pH balance of the product, as each specific enzyme works best with a particular pH. The pH of a product is a contributing factor that affects how deep the product will work and can also attribute to the healing process. The lower the pH, the stronger the product can be. Keep in mind, products below 3.5 pH are for professional use only, not to be sold to end consumers in order to protect from possible damage to the skin from improper use. A daily-use product containing enzymes and/or acids will likely sit around 4.0 - 5 pH, however, a professional-use product can be lower in order to achieve a stronger, more efficient exfoliation.

Molecular weight also needs to be considered in the same consideration as pH does, as it affects the depth of penetration of the product and the recovery timeframe. For example, due to its molecular weight being the largest, making it work only superficially (not deep down to the dermal layers), Mandelic Acid is considered the most gentle acid whereas lower molecular weight acids like TCA and Polyphenol work deepest into the skin.  The FDA does not allow concentrations beyond 2% of salicylic acid in OTC skincare, compared to Mandelic & Lactic Acids  which are allowed in percentages up to 5% in OTC skincare. That is because Salicylic Acid molecules are smaller, meaning they're able to penetrate deeper into the skin making it a more aggressive acid than Mandelic and Lactic Acids (even when the Mandelic & Lactic Acid percentage is higher than the Salicylic Acid).

It is imperative for Estheticians and end-consumers to check the label of the product for directions, or contact the manufacturer of the product for guidance on how long to leave the enzyme or acid on the skin, how often it should be used, learn of any contraindications, and how to follow proper post-care.