The PSA on PHA: Why this new acid may be the key to gentler exfoliation

One of the reasons I enjoy watching K-dramas so much is because they give me #skingoals; both male and female actors always seem to have smooth, glowing complexions! I've always been more of a skincare addict than a makeup junkie, so the Korean beauty concept of glass skin definitely appealed to me. In a jiffy, makeup can be used to mimic the look but I wanted something that was a bit more permanent. Was it at all possible to get my skin to look like glass, without needing a K-idol budget?

There are two key features of the glass skin look: 1) smooth texture without any noticeable pores, and 2) a bright, almost dewy-looking complexion. Regular use of both AHAs and BHAs has helped a lot with improving my skin's texture, but to make it look really glowy, PHAs complete my skincare routine!


Poly Hydroxy Acids (PHAs) are also a kind of chemical exfoliant similar to AHAs, but it's much gentler and more hydrating. They have been clinically proven to have similar anti-aging and skin smoothing effects without as much risk for irritation, so this type of acid can be used even by sensitive and mature skin. This skincare active has actually been around for a long time but until recently, the founders of Neostrata (who discovered both AHAs and PHAs) held the exclusive patent. The most popular type of PHA is gluconolactone.

I regularly use both AHA and BHA in my routine so I stopped them to exclusively try the CosRX Low pH PHA Barrier Mist and the CosRX PHA Moisture Renewal Power Cream for my evening skincare routine after cleansing. 

I'm used to applying a hydrating toner (or two) after cleansing my skin and applying acids, but I only sprayed the CosRX Low pH PHA Barrier Mist (P1,000 from during the first testing week to see what it could do. Well, it felt exactly like water - it had no scent, it wasn't sticky or oily, and it was easily absorbed by my skin. While that might sound unimpressive, I realized that those features are actually important. Because this product is actually meant to be applied on top of other skincare layers, I appreciate that it doesn't add any weight or cause any discomfort. I've also tried using this on top of makeup and its very neutral formula refreshed my skin without interfering with the makeup layers.

The frosted plastic packaging looks gorgeous and is durable enough to tote around in my purse. My favorite feature though is the extremely fine mist it dispenses! It almost feels like an aerosol spray, and I definitely plan to reuse the container when I've used up the product. The instructions say to pat in the mist after spraying though.

I panicked a little after the first time I used this because I simply applied it all over my face before realizing I would be getting an acid product on my eye area as well. I'm happy to report that it didn't cause any irritations or stinging, but to be sure, you may want to cover your eye area when misting.


I'm used to seeing (and using) the CosRX acids in liquid form but it makes sense for the CosRX PHA Moisture Renewal Power Cream (P1,250 from to be formulated this way. It's in this product that I'm best able to appreciate the other star product in the line: 50% coconut fruit extract! It's lightweight but feels richly moisturizing, even feeling a little bit greasy and sticky when I over-apply.

The packaging recommends it for dry skin users but my husband (who has very oily skin) immediately liked this product at first try, claiming that it "makes his skin feel nice". To be honest, his quick reaction was a surprise for me because it wasn't until after a week of usage that I saw or felt the benefits. My skin looked smooth again (after being on acid withdrawal), felt extra bouncy, and looked so dewy that the shine on my forehead got kind of distracting. 

At just 3% PHA, the weak acid content means that it can really take a while to see results but the 2% niacinamide content is good for stimulating collagen production. I also like the faint coconut-y scent that the cream has but as it is pretty rich, I would strictly reserve this for nighttime usage.

After using the PHA products on their own, I incorporated them into a full routine with the CosRX Galactomyces Essence, CosRX BHA Blackhead Power Liquid, and CosRX AHA 7 Whitehead Power Liquid (with the acids used on different days). Unlike in my trial of the CosRX Two-in-One Poreless Liquid, my skin didn't get overexfoliated when I used the PHAs with the AHA Liquid. I don't really see the need to use these two together, but it can be a good pairing if you have dark spots or hyperpigmentation. If that is not a concern for you, I think PHA would be a better acid option because unlike AHAs, it DOES NOT increase skin's sensitivity to the sun so I was able to continue using acids even when I went on a beach trip!

My HG discovery though is the pairing of the BHA Liquid and PHA Cream. I got some clogged pores in the week that I was testing PHA exclusively, but using a BHA in my routine again cleared my pores while the PHA kept my skin hydrated (because BHA is actually drying). The photo below is my bare skin, after a light morning cleanse to ensure that my skin is free from the products I had applied the night before.

Apart from the few red bumps leftover from my BHA-free period, this is pretty much the best state that my skin has been in and the closest I've come to achieving that coveted glass skin look! Let's see if extended use will refine the texture on my cheeks further.

Are you a fan of the glass skin look as well? Have you tried using PHA? What products are you using to achieve this look?

CosRX Low pH PHA Barrier Mist ingredients: Cocos Nucifera (Coconut) Fruit Extract, Gluconolactone, Ethylhexylglycerin, Butylene Glycol, 1,2-Hexanediol, Illicium Verum (Anise) Fruit Extract, Scutellaria Baicalensis Root Extract, Polysorbate 60, Caprylic/Capric Triglyceride, Allantoin, Sodium Hydroxide

CosRX PHA Moisture Renewal Power Cream ingredients: Cocos Nucifera (Coconut) Fruit Extract, Butylene Glycol, Glycerin, Caprylic/Capric Triglyceride, Helianthus Annuus (Sunflower) Seed Oil, Cetearyl Alcohol, Gluconolactone, Niacinamide, Betaine, Dimethicone, Cetearyl Olivate, Sorbitan Olivate, 1,2-Hexanediol, BeesWax, Elaeis Guineensis(Palm) oil, Elaeis Guineensis(Palm) Kernel Oil, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Ethylhexylglycerin, Citric Acid, Xanthan Gum, Sodium Hyaluronate, Allantoin