COSRX
The AHA 2 BHA 2 Blemish Treatment Serum
A blemish serum carrying glycolic acid and salicylic acid, the AHA and BHA behind the name, though this bottle's own list does not declare a percentage for either.
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- Suited to
- DryDehydratedTexturedCongested
- Helps with
- DehydrationRough surface textureUneven tone and dullnessExcess oil
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How it works
An acid serum is the one step in a routine that should not be doubled up, and this one carries two acid types at once: glycolic acid and salicylic acid, with gluconolactone behind them. It goes on in the evening after cleansing, before moisturizer, on skin that is dry rather than damp. Zinc PCA, allantoin and dipotassium glycyrrhizate are on the same list, which is what keeps a short acid formula wearable. Skin that looks congested and marked in the same places is the case it fits. Two or three evenings a week to start, and sunscreen the next morning is part of using an acid at all.
Key benefits
- Glycolic acid is the AHA on the list; salicylic acid is the BHA.
- Neither acid carries a declared percentage on this bottle's own ingredient list.
- Sodium hyaluronate and allantoin sit further down for a calmer feel.
- Dipotassium glycyrrhizate, a licorice-derived ingredient, rounds out the calming base.
Key actives
Glycolic Acid
the AHA on the list, for surface exfoliation
Salicylic Acid
the BHA on the list, for inside-the-pore exfoliation
Sodium Hyaluronate
a humectant that offsets the dryness acids can cause
COSRX The AHA 2 BHA 2 Blemish Treatment Serum
What do the numbers in AHA 2 BHA 2 actually refer to on the ingredient list?
Glycolic acid sits fourth on this serum's list and salicylic acid fifth, right after the base solvents, on a comparatively short list of only seventeen entries. Neither acid carries a declared percentage on this bottle's own ingredient panel, so the numbers in the name are not something we can confirm as an exact concentration. What is confirmed is that both acids sit high on a short list, ahead of the calming and hydrating ingredients that follow.
Is this too strong for skin new to chemical exfoliants?
Glycolic acid and salicylic acid both sit near the front of the list, which is a real signal that this is formulated as an active exfoliating treatment rather than a gentle everyday serum. Zinc PCA, allantoin, sodium hyaluronate, and dipotassium glycyrrhizate follow to offset some of the dryness acids can cause. Anyone new to combining an AHA and a BHA in one product should start with a thin layer a few nights a week rather than applying it nightly from the start.
Will blemishes clear up after one use of this serum?
Exfoliating acids work by encouraging surface turnover with repeated, spaced-out use, not by clearing a blemish after a single application. Gluconolactone, a gentler PHA-family ingredient, sits alongside the two acids and supports the same gradual resurfacing process over time. Using it consistently a few nights a week and watching how skin responds over several weeks is the realistic way to judge whether it is working.
Can I apply moisturizer right after this serum?
Yes, applying a moisturizer afterward is standard practice with an acid treatment like this one, since sodium hyaluronate on this list only partially offsets the drying effect glycolic and salicylic acid can have. Nothing here is known to conflict with a standard moisturizer or sunscreen used in the same routine. Avoid layering it the same night as a separate strong acid or retinoid product, since stacking actives raises the chance of irritation.
How do I verify this serum is the genuine Korean-market formula?
This bottle's own barcode, 8809598455696, is a real EAN tied to this exact product, so checking that number against your packaging is a useful first step. COSRX additionally verifies units through its own system: enter the batch number and expiration date printed on your unit at the checking page on cosrx.com, read directly from the box itself. Combining the barcode check with the batch verification is the more complete way to confirm authenticity.
- Ships from
- California
Duties are prepaid. Nothing is owed at delivery. Returns are accepted for 30 days, by mail.
Orders ship from our California warehouse, dispatched within 2 business days, and arrive in 3 to 5 days. Shipping is free on orders of $100 or more.
We split shipments free, so one out-of-stock item never holds up the rest of your order.
Where this unit came from
- 1Seoul
Bought as Korean-market stock - 2Customs
Duty paid by us before it enters the US - 3California
Ships domestically, no international leg
We stock the version of a formula that is sold in Korea, not the release a brand prepares for another market under the same name.
Every unit keeps its original barcode and batch code intact, so the unit in your hands can be checked against the brand’s own records.
Import duties are paid by us before the parcel reaches you, so nothing is owed at the door, and returns run for 30 days.
Every claim on this page traces to the unit in the box, the barcode, the batch code and the price you can read for yourself.
Payment and security
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How to use
- Use the AHA 2 BHA 2 Blemish Serum in the evening, after cleansing and before moisturizer.
- A thin layer over the areas that want it, or the whole face, kept clear of the eyelids and lips.
- Wait a minute, then follow with a plain moisturizer the same evening.
- Two or three evenings a week to start. Do not use it in the same routine as another acid or a retinoid.
Worth knowing
- This formula carries an active acid, so pairing it with another exfoliant in the same routine is worth spacing out.
Reviews
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COSRX, Korean-market original
AHA BHA blemish treatment serum, with Glycolic and Salicylic Acid.
Verify your unit when it arrives
Verify your unit when it arrives
Korean-market stock with the original barcode and batch code intact, exactly as it left Korea.
COSRX verifies units itself. Find the verification page on cosrx.com and enter the batch number and expiration date printed on your unit. Read them off the package rather than from us, which is the point.
Source: COSRX FAQ
On the unit itself
- The Korean-market barcode, unaltered from the retail package.
- The manufacturer’s batch code, exactly as the maker printed it.
정품Genuine article, Korean-market stock
What professionals say
What professionals say
What skin-care professionals say about skin care, quoted from the medical sources linked beside each.
As we age, the glue that holds our skin cells together becomes denser, which slows down the natural cell turnover process.
Samantha Stein, PA-CDermatology physician assistant, Cleveland Clinic Pretty much every step of a Korean skin care routine is going to have some component of hydration.
Alok Vij, MDDermatologist, Cleveland Clinic
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