Alpha hydroxy acids. Beta hydroxy acids. These sound like complicated and possibly dangerous chemical compounds you would learn about in high-level chemistry classes, right? Have no fear; these organic compounds will make you beautiful.
Both alpha hydroxy acids and beta hydroxy acids are used in many skincare products as chemical exfoliants. Alpha hydroxy acids, or AHAs, when used in low concentrations, can be used to treat dry skin and keratosis pilaris. At higher concentrations, AHAs cause epidermolysis, which causes the top layer of skin to peel away, revealing new and healthy skin underneath. This can improve the appearance of photoaged skin by reducing wrinkles and lightening dark spots. Common AHAs include glycolic acid and lactic acid. Beta hydroxy acids, or BHAs, act as a peeling agent and can be used to treat acne, photoaging, and calluses. Common BHAs include salicylic acid, citric acid, and malic acid.
These chemical exfoliants sound great, but how do these acids work? The top layer of your skin is called the epidermis. The very top layer of the epidermis is the stratum corneum. This layer consists of dead skin cells known as corneocytes that are ready to slough off with exfoliation. These corneocytes are held together by intracellular bonds. Chemical exfoliants such as AHAs and BHAs break these bonds and encourage desquamation, otherwise known as skin peeling. If the stratum corneum consisted of bricks stacked on each other and held together by cement, these acids would dissolve that cement and allow bricks to easily be removed.
When used correctly, chemical exfoliants such as AHAs and BHAs cause very little irritation and have no lasting negative effects. When used incorrectly, however, chemical exfoliants might leave you worse off than you started. If an acid is too strong for your skin, it might penetrate too deep into lower layers of your skin, breaking too many intracellular bonds and causing healthy, living skin cells to slough off. You could be left with chemical burns and scars once your skin heals. Additionally, AHAs and BHAs can increase photosensitivity, causing sun damage to occur faster than usual. However, this effect can be mitigated by wearing sunscreen daily, and as a bonus, you can prevent the need for chemical exfoliants in the future because photoaging will decrease with the use of sunscreen.
Scary-sounding chemical exfoliants like alpha hydroxy acids and beta hydroxy acids are nothing to be afraid of when you understand how they work and the effects they have. Do your research and you too can be beautiful!
Sources:
Alpha Hydroxy Acids. (n.d.). Retrieved October 2, 2018, from https://cosmeticsinfo.org/alpha-hydroxy-acids
Chemical peel. (2018, May 24). Retrieved October 2, 2018, from https://www.mayoclinic.org/tests-procedures/chemical-peel/about/pac-20393473
EJ, V. S., & RJ, Y. (n.d.). Alpha hydroxy acids: Procedures for use in clinical practice. Retrieved October 2, 2018, from https://europepmc.org/abstract/med/2523288
Heathman, C. (n.d.). Skin Exfoliation. Retrieved October 2, 2018, from https://www.dermascope.com/exfoliation/skin-exfoliation
Kornhauser, A., Coelho, S. G., & Hearing, V. J. (2010, November 24). Applications of hydroxy acids: Classification, mechanisms, and photoactivity. Retrieved October 2, 2018, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3047947/
Trench, B. L., & Nesvig, K. (2017, October 23). Your Guide to Alpha Hydroxy Acids (AHAs) and How They Work. Retrieved October 2, 2018, from https://www.allure.com/gallery/what-you-didnt-know-about-lactic-salicylic-citric-glycolic-acid-creams
Van, E. J., & Yu, R. J. (1984, November). Hyperkeratinization, corneocyte cohesion, and alpha hydroxy acids. Retrieved October 2, 2018, from https://www.ncbi.nlm.nih.gov/pubmed/6096420
