PHAs are the gentle hydroxy acid you need to know about

Here at BEAUTYcrew, we’re big fans of the OG hydroxy acids like BHAs and AHAs. And even the new hydroxy acid on the scene, LHA, has earned a firm place in our skin care rotation. 

But there’s another hydroxy acid that deserves a mention, too (yep there’s more). We’re talking about PHAs – AKA polyhydroxy acids.

What’s the big deal with this lesser known member of the hydroxy acid family, you ask?

Well, we spoke to the founders of Glow Recipe, Sarah Lee and Christine Chang, who’ve utilised the ingredient in their cult-favourite Glow Recipe Watermelon Glow PHA+BHA Pore-Tight Toner ($52 at MECCA) for their lowdown on the lowkey member of the hydroxy-acid lineup.

What exactly are PHAs and how do they benefit the skin?

According to Lee, polyhydroxy acids are great for conditioning virgin skin for harsher hydroxy acid formulations that include hard-hitters like AHAs and BHAs.

“[PHAs are] a gentler acid with a larger molecule size that penetrates more slowly and doesn't typically cause dry or sensitive skin to have a reaction,” the Glow Recipe co-founder explains.

“It provides the same great results as AHAs with minimal irritation, antioxidant benefits, and can even hydrate the skin.”

In fact, it’s for that exact reason that Glow Recipe decided to formulate their sold-out toner and their Glow Recipe Avocado Melt Retinol Sleeping Mask ($38 at MECCA) with the stuff. 

“it pairs perfectly with retinol to rejuvenate and plump the skin from the inside out, [and it] also smooths the skin with minimal irritation while even hydrating the skin.”

But what differentiates PHAs from BHAs, AHAs and LHAs?

Well, as Chang puts it, “unlike BHA, PHA is not oil-soluble and focuses on exfoliating the surface of the skin, whereas BHA focuses on decongesting the pore.”

“[AHAs] help to smooth fine lines, soften texture, diminish dark spots, and clarify pores,” she continues. “They also tell your skin cells to turnover in order to remove old, dead skin and reveal a fresh surface.” 

As for LHAs? “Lipo hydroxy acid is a type of BHA that is similar to salicylic acid but more lipophilic,” Chang explains. “They penetrate less deeply into cells and have the same pH as skin.”

Got it? Good. Now onto the important part: Should you be using PHAs in your routine?

Well, according to Lee, the beauty of PHAs is they work for just about anyone because “PHA has a larger molecular size so it doesn’t penetrate as deeply, causing less irritation and making it better suited for sensitive and oily skin.”

“Because of its sensitive nature, it is a great acid for people with acne and pore concerns and is very helpful in getting rid of unwanted blackheads in a gentle manner,” the Glow Recipe co-founder tells BEAUTYcrew..

The brand uses a specific form of the hydroxy acid in their products called gluconolactone, that “attracts water and forms a barrier to protect skin and lock in moisture, on top of functioning as an antioxidant.” This makes it a great entry-level pick for all skin types.

Obviously, as with any hydroxy acid, it always pays to err on the side of caution. Start low and slow with PHA, just like when you introduce any new skin care ingredient into your routine, by alternating days and amping up application once tolerance has been established.

Chang recommends using “acids in the day time, and apply[ing] your acne treatments overnight,” to avoid irritation. She also warns against using “acids on broken or damaged skin, as this can potentially cause irritation.” 

And most importantly, remember to “always wear a broad-spectrum sunscreen of at least SPF 30 during the day, as exfoliating acids can make your skin more sensitive to sun damage.”

We recommend:

Glow Recipe Avocado Melt Retinol Sleeping Mask ($38 at Mecca); SOME BY MI AHA BHA PHA 30 Days Miracle Toner ($35 at Adore Beauty); and LIXIR Night Switch PHA/AHA 10% Serum ($38 at Sephora).

Reckon your skin's tough enough to try BHAs? The skin-perfecting liquid exfoliant that’s so popular it sells every minute.

Main image credit: @jennierubyjane