Beauty Skincare This Is the Best Exfoliating Ingredient for Sensitive Skin — and You've Never Even Heard of It By Erin Lukas Erin Lukas Instagram Twitter Erin is a Brooklyn-based beauty editor and has been with InStyle since 2016. She covers all facets of beauty for the site. InStyle's editorial guidelines Updated on February 4, 2019 @ 02:00PM Pin Share Tweet Email Photo: Copyright 2019 Matt And Tish/Stocksy For anyone whose skincare hangups include acne, aging, pigmentation, and dullness, acids can be great for your face. In their various formulations, AHA and BHA acids are the two most common chemical exfoliants used in products. Both remove dull skin from the surface of the face and promote cell turnover. With continued use of these ingredients, skin can become more clear, even, and glowy over time. Despite the benefits of chemical exfoliation, acid, as in the word itself, can be triggering for sensitive skin types. Using AHAs and BHAs can be a recipe for redness, dryness, and flaking for skin that's super reactive. Luckily, PHAs are alternative gentler acids that might be the solution for sensitive skin types who've yet to experience how effective regular chemical exfoliation can be. What Type of Exfoliator Should You Be Using? These "super acids" are starting to pop up more and more on skincare product ingredients, but how are PHAs different from AHAs and BHAs, and what makes it the best acid option for sensitive skin? Keep scrolling for the complete breakdown on PHA acids. WHAT ARE PHA ACIDS? PHAs is an acronym for polyhydroxy acids. They are a second generation of alphahydroxy acids, or AHAs as they're more commonly known. If you're curious as to whether or not PHA acids are in some of the products you're already using, gluconolactone, galactose, and lactobionic acids are the most common PHAs found on ingredient lists. "As a category, they [PHAs] act as an exfoliant, plus stimulate the process of cellular turnover," says Ava Shamban, MD, Beverly Hills dermatologist and founder of SKIN FIVE. "This may improve clogged pores and breakouts, as well as the appearance of fine lines." These acids can also minimize pigmentation caused by photo aging, sun damage, or exposure to UV rays that have directly effected the melanocytes [skin cells that form melanin]. Similar to AHAs, Dr. Shamban says that PHAs also attract and bind water molecules to the skin which can help keep skin hydrated. HOW ARE THEY DIFFERENT THAN AHA AND BHA ACIDS? PHAs are larger in molecular size than AHAs and BHAs, which means that they're only able to exfoliate the outer layers of the skin. "AHAs are the middle of the road," explains Dr. Shamban. "BHAs really dive deeper into the skin, dissolving sebum and dead skin cells down in the pores, so they are often more suitable for oily skin and keeping acne at bay." While PHAs might not be the ideal acid to use if acne is your main concern, they are great for hydration and signs of aging. "These acids are humectant, so they have the ability to support moisture retention in the extracellular matrix, giving a firmer, plumper appearance to the skin," says Dr. Shamban. "They also render excess iron in the skin 'inactive,' purging an element that is often in overdrive as we age and can speed up the cellular aging process." Melatonin Is the Anti-Aging Ingredient You're About to See Everywhere WHY SHOULD YOU USE PHA ACIDS? PHA acids are a great addition to a skincare routine focused on anti-aging, or sensitive skin types that react to other chemical exfoliants. "Even those with more sensitive skin or who are highly reactive can easily tolerate PHA more readily," says Dr. Shamban. "PHA products are also known to be safe for people with roseaca or some skin conditions like eczema, which is not possible with AHA and the BHA acid groups." Another reason to switch PHAs: Sun sensitivity isn't an issue. Many products with AHAs and BHAs in them recommend applying them at night or limiting your sun exposure if used in the morning. Dr. Shamban says that PHAs are completely safe to use in your daily skincare routine, but don't skip on wearing sunscreen and a hat if your plans for the day include being outside. HOW DO YOU USE PHA ACIDS? From masks, serums, to moisturizers, you can incorporate PHA acids into virtually any step of your skincare routine. Dr. Shamban says that the ingredient is safe to use everyday, but suggests introducing a new PHA acid product into your routine three times a week and building the frequency up from there. Don't expect to see miracles overnight, but stick with it to see the best results. As for products, there's a handful of options out there that can suit a variety of different skincare routines. Glossier's Solution is an Instagram-popular exfoliating toner that includes AHA, BHA, and PHA acids to clear pores and reduce breakouts, Glow Recipe's Avocado Melt Sleeping Mask combines the firming, moisturizing power of PHAs with everyone's favorite fruit, Zelens PHA+ Bio-Peel Resurfacing Facial Pads are a quick-and-easy way to exfoliate, and PCA's Hydrating Serum boosts moisture levels and plumpness, to name a few. VIDEO: Beauty School: How to Properly Cover A Pimple SO, WHY HASN'T ANYONE HEARD OF PHA ACIDS UNTIL NOW? If this is the first time you've ever heard of PHA acids, you're not alone. Salicylic, glycolic, ferulic, and lactic acids are all extremely effective, which is why dermatologists and brands alike have considered them the gold standard of chemical exfoliants. Dr. Shamban says that thanks to research in product developments and more reasonable market prices, the skincare industry is finally starting to utilize PHA acids by formulating products with them.