If you find yourself reacting to alphahydroxy acids (AHAs) and betahydroxy acids (BHAs), a lesser-known player in the exfoliating game, known as polyhydroxy acids (PHAs), may be your saving grace.
The world of skin-care acids is a crowded space.There’s the stronger, heavy-hitting alphahydroxy acids (AHAs) on one end of the spectrum, and on the other end are the gentle crowd-pleasers known as betahydroxy acids (BHAs). But, right in the middle of the two lies the under-the-radar and often-overlooked exfoliators known as polyhydroxy acids (PHAs), which deserve a closer look (and some space in your medicine cabinet!).
“PHAs are composed of milk-derived lactobionic acid, maltobionic acid and sugar-derived gluconolactone,” explains Davie, FL dermatologist Mariana Blyumin-Karasik, MD. “While they’re a cousin of both AHAs and BHAs, PHAs are unique due to their larger molecular size. Because of their structure, their exfoliating properties are limited to the most superficial skin layers, which not only makes them suitable for a large variety of skin types, but also allows them to deliver a major glow.”
PHAs are gentle.
Don’t let the word “acid” fool you. Benign enough to be used up to twice per day, PHAs are the most user-friendly exfoliant in the acid game (for comparison, some AHAs can only be used one to two times per week). “PHAs work as a chemical exfoliant by disrupting cellular adhesion to loosen and shed overdue skin cells and keep cell turnover on schedule,” cosmetic chemists Gloria Lu and Victoria Fu explain. However, due to their size, their skin-sloughing properties are limited, and Dr. Blyumin-Karasik says this makes them suitable for a variety of skin types including sensitive and pigment-prone. “Any patient who is trying to minimize breakouts and blemishes, enhance their complexion and boost their skin luster is a solid candidate.” If you’re looking for an extra luminous boost, Fu says PHA can be paired with other aggressive actives to help boost efficacy without irritation.
PHAs play nice with other ingredients.
New York dermatologist Marina Peredo, MD says PHAs are versatile, so not only are they suitable for any skin type, but they can also be mixed with a wide variety of other ingredients. “Many highly efficacious ingredients, such as glycolic acid and retinoids, can be irritating and drying,” says Lu. “PHAs, on the flip side, are gentle, so we add them to our formulas to balance out those harsher ingredients. Most commonly, we pair PHAs with retinoids.” Audrey Bois Nicolai, head of brand for science-backed Noble Panacea, agrees, saying “the exfoliation properties of the retinol increase the penetration of PHA. Furthermore, retinol boosts the cellular renewal process even more by acting as an exfoliant.” While this combination may seem too drying, Noble Panacea’s newest PHA-infused product—it uses innovative OSMV technology to control the release sequence of both actives—allows the ingredients to stay controlled within their therapeutic level.
PHAs are the second generationof alphahydroxyacids (AHAs).
—Marina Peredo, MD
While they may pop up on the ingredient list of some of your vanity staples, not all products are created equal. PHAs are only effective at a percentage of 7 percent and above, and if left on the skin for a long period of time, note Fu and Lu. “We don’t prefer PHAs in our cleansers because they are washed off the skin in a matter of seconds. We do, however, like to add them into aqueous serums, toners, treatments, and sometimes creams for both the face and body.” If you’re on the hunt for PHA-filled products, Dr. Peredo says they’re easy to find, but likely not at your doctor’s office. “We don’t prescribe PHAs in our office because we opt for stronger acids like AHAs, so your best bet is to find them at your favorite retail stores.”
PHAs are multitaskers.
“Another aspect of PHAs that make them unique is that they are multitaskers,” Dr. Blyumin-Karasik says. “They fortify the skin barrier with their antioxidant powers, they unleash a plumping effect by opposing collagen breakdown, and they have a lower sun-sensitivity predisposition than other exfoliating acids, which makes them more desirable for those with an active outdoor lifestyle.” Bois Nicolai adds that PHAs also contain many hydroxyl groups, “meaning they act as a humectant, attracting water to the skin to deliver deep hydration.”
These PHA-infused face and body products guarantee smooth skin sans any harsh side effects.
