Asking for a Friend: What Is a PHA?

Acid. The biggest thing to happen to our faces since we all discovered the absolute glow up that is vitamin C, right?

It feels like the entire skin-curious collective has fallen hook, line, and sinker for acid-infused skincare formulas, and that's largely due to the fact that few ingredients can resurface, exfoliate, clarify and make skin gleam quite like them.

If you're properly clued up (and you should be-acids aren't toys), you'll understand that there are a variety of acids that each serve a different role. Sorting your salicylic acid serums from your glycolic acid toners is vital in ensuring you're using the acid that's right for your skin type. But just as we got to grips with the difference between AHAs and BHAs (clueless? Don't worry, as there's a refresher course coming up), a new breed of acid has crept up to the fore to offer its own set of persuasive benefits: PHAs.


Okay, so let's take this from the top.

First, you've got your AHAs (alpha-hydroxy acids), and that covers your glycolic, citric and lactic acids. They all have their own strengths, but they mainly work by nibbling away at skin cells to reveal the glowier skin hiding underneath. AHAs can be pretty hardy, so depending on the concentration of your product, you probably want to limit your usage to once or twice a week. As always, start off slow and see how you go.

Then you have your BHAs, or beta-hydroxy acids, which is where salicylic acid can be found. This type of acid is brilliant at flushing out blocked pores, which is why you always hear it recommended for things like acne or keratosis pilaris.

And then comes PHAs or poly-hydroxy acids-the new-gen AHAs if you will. Yes, this acid moonlights in exfoliation, but their real claim to fame is that they come armed with tones of antioxidants and anti-inflammatory properties "They're a special type of AHA that strengthen the skin's barrier function and fight the signs of aging without the irritation of the classic AHA," explains dermatologist Frances Prenna Jones.

And that's their real pull-PHAs are a lot gentler on the skin because they have a larger molecule size. That means they take a little longer to properly sink in, and they'll never travel quite as deep as say, a straight-up AHA. But if you have sensitive skin, that's great news, as it's likely that you'll be able to apply a PHA with little to no sting.

Then add in the fact that PHAs are humectants (meaning they retain moisture reserves) and you definitely have a recipe for the most glowing of complexions.

Want in? Below you'll find a handful of our favorite skincare products containing PHAs.

Lixir Night Switch PHA/AHA 10% $28Shop

We were massive fans of Lixir when it first launched (and not only because it's the most Instagrammable brand since Glossier) because it offers pared-back formulas without a load of fluff or filler ingredients. This night serum chips away at the build-up of dead skin cells on the surface, so it is perfect if your skin appears to be wearing a winter coat of dullness.

Glossier Solution $24Shop

There's a lot going on in this formula, so I wouldn't recommend using it every day-and definitely not if your skin is super sensitive. But it contains a blend of AHAs, BHAs, and PHAs that seem to be having a remarkable effect on clearing up cases of acne. Just go steady.

Zelens PHA+ Bio-Peel Resurfacing Facial Pads $95Shop

By buffing away layers of dead skin and encouraging skin density, these pads do a great job at making skin look and feel evener. They'll also help lock in water from the atmosphere to amp up that glossy smoothness of supermodel skin.