A-Z of AHAs
In the wide world of skin care, it can be hard to keep track of which ingredients do what. But, in the age of “trending” skin-care routines and easily influenced buyers, it’s more important than ever to understand what’s inside your products. Enter alphahydroxy acids (AHAs), one of the trendiest skin-care ingredients as of late. While most beauty and self-care aficionados understand what it means to incorporate acids into a skin-care routine, having a solid grasp on when and why to use different acids can make all the difference in creating a glowing, healthy complexion. Ahead, skin-care experts walk us through all things AHAs, from what they are, to how to use them and products to try.
99k: The average monthly searches for ‘AHAs’ alongside skin care, up 3.7 percent since last year.
Source: SPATE
What Are AHAs and How Do They Work?
“Alphahydroxy acids are a group of water-soluble acids that are naturally found in various foods,” says Omaha, NE dermatologist Joel Schlessinger, MD. “In essence, they work to exfoliate the skin by breaking down the bonds or ‘glue’ that hold dead cells to the skin’s surface. This facilitates the cells’ shedding and makes way for newer, fresher skin cells.” However, as Dr. Schlessinger explains, the word “AHA” on a skin-care label serves as a blanket term for any one of dozens of alphahydroxy acids, all of which serve different purposes. “All acids are of different weights and sizes and penetrate different levels in the skin’s structure,” adds celebrity aesthetician Nerida Joy. “The most common alphahydroxy acids found in skin-care products are glycolic acid, lactic acid and citric acid. They each have their own unique purpose.”
While there is a wide array of AHAs, Joy explains that combining them is a great way to treat countless skin issues simultaneously. “Having two or three different acids in one formula provides a more effective result on the skin’s structure, as each acid reaches a different layer of the skin based on its weight and size,” she says. “AHAs reach live cells in the skin—our fibroblast cells—which is why we often feel tingling when using them. But, as a result, AHAs can tighten skin, reduce pore size, lighten brown spots and melasma, improve scarring and pitting, and lessen the depth of wrinkles all at once.”
Victoria Fu and Gloria Lu, the cosmetic chemists and cofounders behind Chemist Confessions, say the most common misconception about AHAs is that sensitive and dry skin types shouldn’t use them. “In fact, AHAs at lower levels can function as hydrators for dry or sensitive skin, and some exfoliation can actually help with dry skin.”
Glycolic acid is searched an average of 255.3K times per month alongside skin care, with searches up 21.1 percent since last year.
Source: SPATE
The Most Popular AHAs Used in Skin Care
Glycolic Acid: Derived from sugar cane and boasting a small molecular size, glycolic acid is considered the most potent AHA in skin care because of its ability to deeply penetrate the skin, Dr. Schlessinger explains.
Lactic Acid: “This acid can be derived from sour milk products or vegan sources like fermented foods,” says Dr. Schlessinger. “It’s known to be gentler than glycolic acid because of its larger molecular size. In addition to exfoliation, it also has humectant (water-attracting) properties.”
Citric Acid: Joy explains that citric acid, which is derived from citrus fruits like lemons and limes, is the AHA with the heaviest molecular weight, which impacts how deeply it can penetrate the skin. “Citric acid also features antioxidant properties, helping to neutralize the known aging effects of environmental factors like pollution,” adds Dr. Schlessinger.
Mandelic Acid: Dr. Schlessinger explains that mandelic acid stands out among the other AHAs because it “also features a larger molecular size. This makes it potentially less irritating, and unlike any other AHAs mentioned here, it also has antibacterial properties.”
Dos and Don’ts: Incorporating AHAs Into a Skin-Care Routine
As with all skin-care ingredients, there are better and worse ways to go about incorporating AHAs into a skin-care routine. It all boils down to understanding the makeup of the acid you’re dealing with. “The pH of an acid is crucial,” says Joy. “If the pH is too low—below 2.5—it can burn the skin, causing issues such as hyperpigmentation and melasma. The delivery system of the product containing the AHA is equally as important, and combined ingredients must have synergy so that irritation doesn’t occur. For example, products that contain an acid combined with niacinamide are known to cause irritation on many people. Active formulas must be respected, as they are not designed for all skin types and skin colors.”
Regarding Joy’s note on delivery systems, she recommends integrating AHAs into a routine through serums and moisturizers. “I prefer to use AHAs in serum or moisturizer forms, as I like the idea of the active benefits staying on my skin, rather than washing off,” she says. Fu and Lu explain further that there are several ways to use AHAs, and it comes down to what concentration of AHA works best for each skin type. “If you’re a beginner, we recommend looking at the 5 to 7 percent AHA range to use nightly. Most users fall into the 10 to 15 percent range and use AHAs as a nightly serum. But, if you’re a pretty seasoned AHA user, a once-a-week at-home peel with 15-percent AHAs and a pH of 3.0 or higher can be efficient for tackling concerns like hyperpigmentation and wrinkles.”