What are they?
Polyhydroxy acids (PHAs), such as gluconolactone and lactobionic acid, are among the newest alpha hydroxy acids (AHAs) to hit the skincare market. Made up of larger molecules than traditional AHAs, PHAs are typically gentler on the skin, causing less peeling, flaking and dryness. Unlike some AHAs, which can dry out the skin, PHAs are ideal for sensitive or dry skin types.
You’ll find them in
PHAs are frequently used in anti-aging and correcting skin treatments, like face lotions, creams, serums and eye products. Additionally, they’re found in acne treatments and products for the body, hands, feet and even hair.
Consistent use of PHA products can improve skin in many ways. PHAs:
- Promote cell turnover. By sloughing off dead skin cells, PHAs reveal smooth, healthy new cells underneath.
- Attract water to skin. PHAs are humectants. By drawing in moisture, they help skin stay hydrated. When skin is sufficiently moisturized, it looks smoother and healthier.
- Reduce wrinkles. In one study, after PHAs were used twice a day for six weeks, results revealed “a decrease in the number, depth and spacing of fine lines, wrinkles and crow’s feet,” Elizabeth Briden, M.D., a dermatologist at the University of Minnesota, tells Skin & Allergy News. PHAs are also effective in combination with retinoids.
- Strengthen skin’s barrier. Our skin barrier, or stratum corneum, plays a vital role in keeping out irritating chemicals and substances. Because PHAs help improve barrier function, they can make skin less vulnerable to irritants.
- Fight free radicals. Gluconolactone is an antioxidant known for its free radical-fighting ability, protecting skin from harmful UV exposure.
- Lighten hyperpigmentation. Especially when used with hydroquinone, PHAs can lighten hyperpigmentation and photodamage.
- Reduce flare-ups in inflammatory conditions. Dr. Briden notes that using complex PHA products can lower inflammatory episodes of acne, rosacea, dermatitis, psoriasis and melasma.
If you’d like to incorporate PHAs in your skincare routine, you have many options:
Who should avoid PHAs?
PHAs are generally considered safe for all skin types. However, check with your doctor before using PHA products if you:
- Have a known allergy or sensitivity to PHAs or AHAs.
- Use prescription acne treatments, (especially topical retinoids or Accutane).
- Are pregnant.
Learn everything you need to know about anti-aging skincare in our Anti-Aging Handbook.