All About Polyhydroxy Acids (PHA) in Skincare

If you have sensitive skin, chances are you may find many chemical exfoliants, depending on the formula, to be too harsh or even stripping. Moreover, depending on how sensitive your complexion is, you might find that the same goes for many physical exfoliators on the market, too. So how does one with a fragile epidermis effectively exfoliate, sans irritation? With polyhydroxy acids, that’s how. 

Also known as PHAs, polyhydroxy acids are chemical exfoliants that are considered to be just as effective as AHAs, but significantly less sensitizing. The most common ones include gluconolactone, galactose, and lactobionic acid, which you can find in various toners, serums, and exfoliating treatments that target sensitive skin types. 

“PHAs work very similar to AHAs and BHAs, but differ in that they have a larger molecule size and therefore take longer to sink in, so they don’t penetrate as quickly or as deeply, thus making them a gentler option compared to other chemical exfoliants,” says New York City board-certified dermatologist, Dr. Robert Finney, MD. “They can be great for people with combination or sensitive skin as a way to gently exfoliate to help keep an even skin tone that’s smooth and bright, but without nearly as much irritation.”

Still, Dr. Finney always recommends starting off slow when it comes to chemical exfoliants, and PHAs are no exception. 

“It’s a good rule of thumb for any product that exfoliates to start off applying it just one to two times a week to see how your skin tolerates it,” he says. “If your skin does well with it, then you can increase the use of that product, but remember that your tolerance may fluctuate according to seasons, so always be sure to listen to your skin and what it needs.”

Exfoliation benefits aside, it’s worth pointing out that PHAs actually double as humectants, meaning they bind to water and help retain healthy moisture levels. Here’s Dr. Finney with a hot tip:

“It’s best to apply PHAs to slightly damp skin and then to moisturize right after to trap in water and boost hydration,” says Dr. Finney.

Written by Kaleigh Fasanella for Youth To The People