Are They Dupes?: Paula’s Choice Skin Perfecting 2% BHA Liquid Exfoliant VS Cosrx BHA Blackhead Power Liquid

Last Updated on February 25, 2026 by Giorgia Guazzarotti

Ask any skincare guru what the best BHA exfoliant for oily, acne-prone skin out there is and they’ll say Paula’s Choice Skin Perfecting 2% BHA Liquid Exfoliant (I personally agree). For years, it literally had no competition. Everything else either had too little BHA or a pH that deactivated it. Now, Cosrx BHA Blackhead Power Liquid is threatening to knock its off its throne. Those who tried it swear the Korean newcomer does a better job: it unclogs pores faster, it’s gentler and doesn’t leave your skin an oily mess. But, only those of these claims are true. The false one? A big reason why I won’t switch. Here’s the truth about these two dupes and which one can really fight acne:

What Ingredients Do These BHA Exfoliants Have In Common?

BHA TO EXFOLIATE SKIN AND PORES

Technically, Paula’s Choice Skin Perfecting 2% BHA Liquid Exfoliant and Cosrx BHA Blackhead Power Liquid are both BHA exfoliants. But, they DON’T use the same form of BHA. Paula’s Choice uses Salicylic Acid, an oil-soluble exfoliant that dissolves the “glue” that holds skin cells together, so they can slough off your skin instead than getting stuck in your pores and clogging them up.

While it’s at it, it also gets inside the pores to get rid of all the crap that’s accumulating in there. That’s what makes it such a good fighter against blackheads, whiteheads and pimples. Plus (yep, salicylic acid has more than one superpower), it has anti-inflammatory properties that reduce irritations and redness.

Salicylic acid is commonly used everywhere… apart from Korea. The country has very strict laws about salicylic acid use in skincare (funny when you think Koreans put literally anything – from snail slime to jellyfish – into their products!). Brands get around them by using a different version of salicylic acid: betaine salicylate. (FUN FACT: Paula’s Choice uses betaine salicylate in the BHA exfoliants it sells in Korea. 🙂 )

But is betaine salicylate as effective as salicylic acid? We don’t know. The manufacturer swears it is – if you use double the amount! So, to get the results 2% salicylic acid gives you, you need to use 4% betaine salicylate.

FYI, some websites that sells Cosrx BHA Blackhead Power Liquid proudly boast that it has 4% BHA. This is to trick you into thinking that’s more powerful than Paula’s Choice and other exfoliants that use 2%. But if this study is true, that’s BS. It has more because you need to use more to get the same results. Don’t fall for it!

Related: Why Salicylic Acid Is The Key To Spot-Free Skin

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What Else Is In These BHA Exfoliants?

COSRX BHA BLACKHEAD POWER LIQUID INGREDIENTS

• Salix Alba (Willow) Bark Water: So this is basically water that’s been infused with white willow bark extract instead of plain H2O – it’s like the formula’s base but make it functional. Willow bark naturally contains salicin, which is a gentler, plant-derived cousin of salicylic acid, so it’s supposed to have mild exfoliating and anti-inflammatory properties. Mild is the key word here. Don’t expect it to do much.
• Butylene Glycol: This is a humectant and solvent – it pulls moisture into the skin and also helps dissolve and carry other ingredients evenly throughout the formula.
• Niacinamide: Your ride-or-die for like five different skin concerns at once. Niacinamide is a form of vitamin B3 that regulates sebum, fades dark spots, minimizes the look of pores, strengthens the skin barrier, and calms redness. It works really well alongside the exfoliating ingredients here because it helps balance the skin while things are being cleared out. Heads up though – some people with very sensitive skin or rosacea can get a temporary flush from it, especially at higher concentrations.
• 1,2-Hexanediol: Think of this as a preservation booster and humectant combo – it helps keep the formula stable and free of microbial growth without being a full-on traditional preservative.
• Arginine: This is an amino acid (like, literally a building block of protein) and in skincare it acts as a conditioning agent that helps repair the skin barrier and neutralize any acidity in the formula.
• Panthenol: This is pro-vitamin B5 and it is so good for keeping skin calm and hydrated. It converts to pantothenic acid on the skin, which supports barrier repair, soothes irritation, and locks in moisture.
• Sodium Hyaluronate: The smaller, more skin-penetrating form of hyaluronic acid – it can actually get into the deeper layers of the skin rather than just sitting on top. It holds like a thousand times its weight in water, so it’s there to plump, hydrate, and counterbalance any drying effect the exfoliants might have.
• Xanthan Gum: This is a natural thickener and texture agent – it’s what gives the formula its gel-like consistency so it actually feels like something when you put it on your face and doesn’t just run everywhere.
• Ethyl Hexanediol: Another multitasker – this one acts as both a humectant that helps with skin feel and a preservation booster that extends the shelf life of the formula.

PAULA’S CHOICE SKIN PERFECTING 2% BHA LIQUID

• Water (Aqua): The base of the formula – pretty much every water-based skincare product starts here. It’s the solvent that everything else dissolves into and what gives the product its liquid consistency.
• Methylpropanediol: A humectant that draws moisture into the skin, but its main job here is probably as a solvent and penetration enhancer – meaning it helps other ingredients, specifically the salicylic acid, absorb more effectively into the skin.
• Butylene Glycol: Another humectant and solvent – it pulls in moisture and helps keep the texture smooth and spreadable.
• Polysorbate 20: A surfactant and emulsifier that helps keep everything mixed together evenly, especially since salicylic acid can be tricky to stabilize in a water-based formula. It also gives the product a slightly smoother skin feel.
• Camellia Oleifera Leaf Extract: This is green tea extract, and it earns its place here. It’s rich in polyphenols (particularly EGCG) which have solid antioxidant and anti-inflammatory properties. In an exfoliating formula it helps calm the skin and counteract some of the potential irritation from the salicylic acid.
• Sodium Hydroxide: This is lye, but don’t panic – it’s here in tiny amounts purely to adjust the pH of the formula. Salicylic acid works best around pH 3-4, so the formula needs to be acidic enough for the acid to actually function, and sodium hydroxide helps dial that in precisely.
• Tetrasodium EDTA: A chelating agent that binds to metal ions in the water and formula that could otherwise destabilize the product or reduce the effectiveness of the other ingredients. Basically it keeps the formula clean and shelf-stable.

WHICH FORMULA IS BETTER?

Not only Cosrx BHA Blackhead Power Liquid and Paula’s Choice Skin Perfecting 2% BHA Liquid have a different active ingredient. The rest of the formulas are different too!

Cosrx is more hydrating. It has hyaluronic acid, a moisture magnet that attracts and binds to the skin up to 1000 times its weight in water. Plus, a big dollop of niacinamide, a multitasker that hydrates skin, soothes irritations, reduces fine lines, fades away dark spots and treats acne. You name it, it does it!

Paula’s Choice is a little oilier. It has a big drop of methylpropanediol, another moisture magnet. But unlike hyaluronic acid, it makes your skin look a bit greasy (not the best look if your skin’s already oily). But it has green tea to soothe irritations and fight wrinkles. Plus, it has the real deal, salicylic acid. That alone makes it the better formula, oiliness or no oiliness.

Related: Why You Need To Add Hyaluronic Acid To Your Skincare Routine, No Matter Your Skin Type

What’s The Texture Like?

Paula’s Choice Skin Perfecting 2% BHA Liquid is oily and leaves a shiny sheen on the skin – so if you’re already oily or you’re putting this under makeup, just know it’s going to look a little glazed. Cosrx BHA Blackhead Power Liquid is noticeably lighter and absorbs faster. I wish PC had the same texture!

What’s The Packaging Like?

Paula’s Choice comes in a dark bottle , which is sleek and gets the job done. Cosrx goes with a see-through bottle – not as cute, but you’ll never have that annoying moment of shaking the bottle wondering if it’s empty. They’re equally easy to use, it really just comes down to whether you care about how it looks on your shelf.

How To Use Them

Every other night after cleansing is your starting point – let your skin get used to it before you go all in. If you’re breaking out constantly and your skin is pretty tough and resilient, daily use might work for you, but that’s genuinely not most people. Give it time, be consistent, and don’t convince yourself that using it more often will speed things up – it won’t.

Which Of The Two Should You Go For?

I’m a sciencey beauty blogger. I have to recommend you to go with Paula’s Choice simply because salicylic acid is tried and tested while studies on betaine salicylate are still lacking. *sighs*

And if salicylic acid is already working wonders for you, why rock the boat and switch things up? If the oily finish really bothers you, Paula’s Choice has plenty of other products with salicylic acid. Check this quick guide here to find out the right one for you.

The only exception? If your skin’s so sensitive it can’t tolerate salicylic acid, then betaine salicylate and Corsx is well worth a try. 

Related: The Complete Guide To Paula’s Choice BHA Exfoliants: Which One Is Right For You?

Price & Availability

Cosrx BHA Blackhead Power Liquid: $25.00 at Look Fantastic, Ulta and Yes Style

Paula’s Choice Skin Perfecting 2% BHA Liquid: $29.00 at Cult Beauty, Dermstore, Paula’s Choice, Sephora and SpaceNK

Is Cosrx BHA Blackhead Power Liquid A Dupe For Paula’s Choice Skin Perfecting 2% BHA Liquid?

Nope. They have completely different ingredients! But Cosrx BHA Blackhead Power Liquid is a gentler version of Paula’s Choice Skin Perfecting 2% BHA Liquid. If you have sensitive skin, give it a try.