Issue link: https://www.ascpskindeepdigital.com/i/1495571
New member benefit! Get the ASCP SkinPro app at ascpskincare.com/skinpro 41 Alpha Hydroxy Acids AHAs are organic carboxylic acids with one hydroxyl group attached to the α-position (or alpha position) of the carboxyl group. These acids are derived from natural sources such as fruits, milk, and sugarcane, and are used in a variety of skin care products. Soluble in water, these molecules work by exfoliating the top layers of the epidermis to reduce the appearance of wrinkles, hyperpigmentation, and uneven skin texture. 3 Molecular size and carbon chain in addition to product pH determine depth of desquamation initiation. Overuse of AHAs could result in photosensitivity and in ammation, so care must be taken when selecting the speci c AHA. 4 Beta Hydroxy Acids BHAs are organic carboxylic acids with one hydroxyl group attached to the β-position (or beta position) of the carboxyl group. BHAs are oil-soluble, making them well suited for treating oily skin conditions. They also have antimicrobial properties, so they can be used to combat bacteria that contribute to breakouts. 5 Recently, it's also been claimed that BHAs reduce the appearance of aging skin with less irritation seen from AHA treatments. This has resulted in a growing selection of AHA- and BHA-infused products. 6 POLYHYDROXY ACIDS It is well known that topical use of AHAs and BHAs have grown to be antiaging and acne- ghting standard ingredients. In the wake of DIY pandemic skin care, consumer demand for alternative acids with less opportunity for in ammation has allowed for a lesser-known group to shine. PHAs are organic carboxylic acids with two or more hydroxyl groups in the molecule attached to carbon atoms of an aliphatic or alicyclic chain. PHAs provide both hydrating and exfoliating properties. 7 They are often used to reduce in ammation and irritation caused by acne and other skin conditions. PHAs provide similar e ects as AHAs, but with the bonus that they do not cause sensory irritation, making them safe for clinically sensitive skin and for use after cosmetic procedures. PHAs also provide additional humectant and moisturization properties compared with AHAs, and can even enhance stratum corneum barrier function. 8 Most PHAs also possess antioxidant properties, making them useful to combine with other products, ingredients, or procedures like laser treatment and microdermabrasion. ESSENTIAL FATTY ACIDS The term essential fatty acids (EFAs) refers to polyunsaturated fatty acids that cannot be synthesized in the body but are necessary for health. There are two families: omega-3 and omega-6—which are both carboxylic acids. 9 EFAs are crucial for healthy skin function and appearance. When a de ciency of EFAs occurs (known as essential fatty acid de ciency), it can result in hyperproliferation of the epidermis and dermatitis, and increased transepidermal water loss caused by a disproportionate abundance of omega-9 fatty acids in the absence of omega-6 and omega-3 fatty acids. Supporting skin health requires both internal and topical EFAs. CONCLUSION As a large group of organic compounds, carboxylic acids have a long history of histological bene t. With advancing science and understanding of skin health, new acids will likely surface to support skin function just as much as their cousins glycolic acid, gluconolactone, and grape-seed oil. Notes 1. Britannica, "Carboxylic Acid," accessed February 2023, britannica.com/science/carboxylic-acid. 2. Ruey J. Yu and Eugene J. Van Scott, "Alpha-Hydroxyacids and Carboxylic Acids," Journal of Cosmetic Dermatology 3, no. 2 (April 2004): 76–87, onlinelibrary.wiley.com/doi/10.1111/j.1473-2130.2004.00059.x. 3. Barbara A. Green, Ruey J. Yu, and Eugene J. Van Scott, "Clinical and Cosmeceutical Uses of Hydroxyacids," Clinics in Dermatology 27, no. 5 (September-October 2009): 495–501, sciencedirect. com/science/article/abs/pii/S0738081X09001564. 4. Green, Yu, and Van Scott, "Clinical and Cosmeceutical Uses of Hydroxyacids." 5. Green, Yu, and Van Scott, "Clinical and Cosmeceutical Uses of Hydroxyacids." 6. US Food and Drug Administration, "Beta Hydroxy Acids," accessed February 2023, fda.gov/cosmetics/ cosmetic-ingredients/beta-hydroxy-acids. 7. Yu and Van Scott, "Alpha-Hydroxyacids and Carboxylic Acids." 8. Barbara Algiert-Zielińska, Paulina Mucha, and Helena Rotsztejn, "Lactic and Lactobionic Acids as Typically Moisturizing Compounds," International Journal of Dermatology 58, no. 3 (March 2019): 374–9, onlinelibrary.wiley.com/doi/10.1111/ijd.14202. 9. Oregon State University Linus Pauling Institute, "Essential Fatty Acids and Skin Health," accessed February 2023, lpi.oregonstate. edu/mic/health-disease/skin-health/essential-fatty-acids. INGREDIENT DECK