COSRX
The Alpha-Arbutin 2 Discoloration Care Serum (Single)
COSRX's discoloration serum, pairing niacinamide with tranexamic acid and 2% alpha-arbutin alongside madecassoside, worn after toner both morning and evening in the single-bottle size.
No reviews yet- Korean-market formula
- Ships from California or direct from Korea
- Korean barcode and batch code intact
- Suited to
- DryDehydratedSensitiveCompromised barrier
- Helps with
- DehydrationBarrier weaknessEarly environmental damageUneven tone and dullness
Sold out.
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- 30-day returns
- Free US shipping on orders of $100 or more
- Tracked delivery to your door
How it works
Uneven tone is slow work, and a serum aimed at it earns its place by being wearable every day rather than by being strong. This one carries niacinamide and tranexamic acid, with alpha-arbutin and acetyl glucosamine behind them and madecassoside further along to keep the base calm. It goes on after toner and before moisturizer, morning and evening, pressed in on damp skin. Marks left behind by old spots, and patches that show most in photographs, are the case it fits. Sunscreen every morning is the other half of that work.
How to use
- Use the Alpha-Arbutin Discoloration Care Serum after toner and before moisturizer, morning and evening.
- Three or four drops covers the face. Press it in with flat palms rather than rubbing it around.
- Toner first, this second, then moisturizer, and sunscreen last in the morning.
- Twice a day, every day, and give it eight weeks. Do not skip the sunscreen; work on uneven tone is undone by daily sun.
COSRX The Alpha-Arbutin 2 Discoloration Care Serum (Single)
How does alpha-arbutin at 2% relate to niacinamide and tranexamic acid on this list?
Niacinamide is fourth on the list and tranexamic acid fifth, both ahead of alpha-arbutin, which is declared at 2% in the seventh position. All three are associated with a more even-looking tone, so this serum layers three tone-focused ingredients rather than relying on alpha-arbutin alone. Madecassoside and ferulic acid appear further down as supporting antioxidant and calming ingredients.
Does this serum contain silicone, and does that matter for my skin?
Yes, dimethicone appears in the first half of the list and methyl trimethicone appears further down, so this is not a silicone-free formula. Those ingredients typically contribute to a smoother, more slip-friendly texture during application rather than an active skin effect. Anyone specifically avoiding silicones in their routine should be aware of both before choosing this serum.
How long does it take for dark spots to look more even with this serum?
Alpha-arbutin, niacinamide, and tranexamic acid all work by supporting a more even-looking tone over weeks of consistent use rather than fading discoloration after a few applications. Madecassoside and licorice root extract sit further down the list as additional supporting ingredients for that same gradual process. Most people apply this daily for six to eight weeks before judging whether tone has visibly shifted, and results vary by skin.
Can this serum be used alongside a brightening product in the same routine?
Nothing on this ingredient list is known to conflict with a separate brightening serum used earlier or later in the routine, and both are commonly paired for tone-focused routines. Sodium hyaluronate and several hyaluronic acid forms further down the list support hydration alongside either product. As with any new combination, introduce one product at a time and watch how skin responds before using both daily.
How do I confirm this single bottle is the authentic Korean-market version?
This bottle's barcode, 8809598454880, is a genuine EAN for this specific product, so checking that it matches your packaging is a useful first step. COSRX runs a separate verification system as well: the batch number and expiration date printed on your unit are entered at the checking page on cosrx.com, read directly from the box rather than a listing. Using the barcode and the batch verification together gives the most complete confirmation.
Not on the ingredient list below: fragrance or parfum, essential oils, parabens, sulfate surfactants, mineral oil or petrolatum and added color.
Full INCI (38): Aqua/Water, Propanediol, Glycerin, Niacinamide, Tranexamic Acid, Acetyl Glucosamine, Alpha-Arbutin(2%), 1,2-Hexanediol, Dimethicone, Dimethyl Isosorbide, Diethoxyethyl Succinate, Butylene Glycol, Citric Acid, Alcohol, Sodium Polyacryloyldimethyl Taurate, Hydrogenated Lecithin, Xanthan Gum, Sodium Metabisulfite, Disodium EDTA, Ethylhexylglycerin, Dextrin, Theobroma Cacao (Cocoa) Extract, Sodium Citrate, Madecassoside, Sodium Methyl Stearoyl Taurate, Sodium Hyaluronate, Tocopherol, Hydrolyzed Hyaluronic Acid, Sodium Hyaluronate Crosspolymer, Hyaluronic Acid, Ferulic Acid, Glycyrrhiza Glabra (Licorice) Root Extract, Panthenol, Arginine, Methyl Trimethicone, Allantoin, Glutathione, Sodium Acetylated Hyaluronate
Ingredient list read from jolse.com on 9 September 2026.
38 of 38 explained
- Aqua/Water solvent
- Water is the base almost every serum, toner and cream is built on. It dissolves the water-loving ingredients and sets how light the finished texture feels. On an INCI list it is usually first, which only means it is the largest single ingredient by weight.
- Propanediol humectant
- Propanediol is a plant-derived glycol used in place of propylene glycol. It hydrates, carries actives into solution, and gives a lighter, less sticky slip than glycerin at the same strength.
- Glycerin humectant
- Glycerin is the most used humectant in skincare. It draws water into the outer layer of skin and holds it there, and it is one of the very few ingredients whose hydrating effect is settled science rather than marketing. Higher amounts feel tacky, which is why it is usually blended.
- Niacinamide active
- Niacinamide is vitamin B3, and it is the most studied active in Korean formulation. It is used at roughly 2 to 5 percent for the look of uneven tone and visible pores, and it is water soluble, stable and comfortable beside almost every other active, which is why it turns up in so many lists.
- Tranexamic Acid active
- Tranexamic Acid is a synthetic amino acid derivative used for the look of stubborn discolouration and post-blemish marks. It is water soluble, stable and comfortable next to niacinamide, which is how it is usually paired.
- Acetyl Glucosamine active
- Acetyl Glucosamine is the sugar unit hyaluronic acid is built from. It is used as a humectant and, at higher levels, for the look of uneven tone, often paired with niacinamide.
- Alpha-Arbutin(2%) active
- Alpha-Arbutin is a plant-derived compound, related to the sugar-bound form found in bearberry, used for the look of dark spots and uneven tone. It is stable in water and works at skin-friendly pH.
- 1,2-Hexanediol humectant
- 1,2-Hexanediol is a glycol used for two reasons: it holds water like glycerin, and it makes a formula harder for microbes to live in, so less traditional preservative is needed. Korean formulas use it heavily for that second reason.
- Dimethicone silicone
- Dimethicone is the most used cosmetic silicone. It forms a breathable film that smooths the surface, slows water leaving skin, and gives the slip that makes a primer or cream feel silky. It is inert and does not penetrate.
- Dimethyl Isosorbide solvent
- Dimethyl Isosorbide is a solvent used to dissolve actives that water and oil both reject, and to carry them evenly through the outer layer of skin. It appears in vitamin C and retinoid formulas for exactly that reason.
- Diethoxyethyl Succinate solvent
- Diethoxyethyl Succinate is a solvent that helps water-resistant actives spread and sink in evenly. It also leaves a light, silky feel.
- Butylene Glycol humectant
- Butylene Glycol is a small glycol that does two jobs at once: it holds water in the top layer of skin and it dissolves plant extracts and actives that plain water cannot. It also thins a formula, which is why watery Korean essences lean on it.
26 more explained
- Citric Acid pH adjuster
- Citric Acid is used in tiny amounts to bring a formula to the pH its actives need, not as an exfoliant at that level. It is an AHA, so at much higher concentrations it can also exfoliate.
- Alcohol solvent
- Alcohol here means ethanol. It dissolves ingredients water cannot, evaporates fast so a formula sets quickly and does not feel heavy, and thins texture. In quantity it can leave dry or reactive skin feeling tight, which is why many Korean formulas avoid it and some deliberately use it for a fast, weightless finish.
- Sodium Polyacryloyldimethyl Taurate thickener
- Sodium Polyacryloyldimethyl Taurate is a polymer thickener that holds a gel stable even with a lot of salt or acid in the formula.
- Hydrogenated Lecithin emulsifier
- Hydrogenated Lecithin is lecithin with its unsaturated bonds filled in, which makes it far more stable. It emulsifies and is the standard shell for the liposomes that carry actives into the outer layer of skin.
- Xanthan Gum thickener
- Xanthan Gum is a polysaccharide made by fermenting sugar. It thickens a watery formula into a gel and holds the whole thing in suspension so nothing separates. Too much of it and a serum turns stringy, which is why it appears in fractions of a percent.
- Sodium Metabisulfite antioxidant
- Sodium Metabisulfite is a sulfite salt used to stop a formula oxidising and browning. It is the ingredient that keeps a vitamin C or plant-extract formula from going amber.
- Disodium EDTA chelator
- EDTA is a chelator: it locks up trace metal ions from water and packaging that would otherwise turn a formula cloudy, off-colour or rancid. It does nothing to skin and appears at a fraction of a percent.
- Ethylhexylglycerin preservative booster
- Ethylhexylglycerin softens skin and boosts a preservative system, which is why it is nearly always sitting beside phenoxyethanol or 1,2-hexanediol. It also cuts down the odour bacteria produce, so it turns up in deodorising products.
- Dextrin thickener
- Dextrin is a starch fragment used to thicken and to give a formula a light, powdery finish. It is also a common carrier for powdered extracts.
- Theobroma Cacao (Cocoa) Extract plant extract
- Cocoa Extract carries polyphenols and a little caffeine. It is used as an antioxidant plant extract and gives a faint warm tint.
- Sodium Citrate pH adjuster
- Sodium Citrate is the salt of citric acid, used as a buffer: it holds a formula at a steady pH rather than pushing it in one direction. It is also a mild chelator.
- Madecassoside active
- Madecassoside is the centella triterpene most associated with the look of redness, and the one brands lead with in cica products. It is water soluble and stable, so it appears in essences as readily as in creams.
- Sodium Methyl Stearoyl Taurate surfactant
- A taurine-based surfactant. Taurates foam well while staying mild, and they keep working in hard water where a soap does not.
- Sodium Hyaluronate humectant
- Sodium Hyaluronate is the salt of hyaluronic acid, and it is what most products labelled hyaluronic actually contain. The salt dissolves more readily and the molecule is smaller, so it sits in the outer layer of skin rather than only on top of it.
- Tocopherol antioxidant
- Tocopherol is vitamin E. It is an oil-soluble antioxidant that protects the oils in a formula from going rancid and works on skin as an emollient, and it is regularly paired with vitamin C because each keeps the other going for longer.
- Hydrolyzed Hyaluronic Acid humectant
- Hydrolyzed Hyaluronic Acid is hyaluronic acid cut into much shorter fragments. The smaller the fragment, the further into the outer layer it can settle, which is why serums stack several sizes together instead of using one.
- Sodium Hyaluronate Crosspolymer humectant
- Sodium Hyaluronate Crosspolymer is hyaluronic acid linked into a mesh. It holds water in a soft gel on the surface rather than sinking in, and it releases that water slowly through the day.
- Hyaluronic Acid humectant
- Hyaluronic Acid is a sugar chain the body already makes, and one gram of it can hold several litres of water. In a formula it is a humectant that pulls water to the surface of skin and holds it in a film, which is what makes skin look plumper while it is there.
- Ferulic Acid antioxidant
- Ferulic Acid is a plant antioxidant from bran and seeds. Its main formulation job is stabilising vitamins C and E so a serum keeps working for longer, which is why the three appear together so often.
- Glycyrrhiza Glabra (Licorice) Root Extract plant extract
- Licorice Root Extract carries glabridin and liquiritin. It is one of the classic plant ingredients used for the look of uneven tone and redness, and it appears in almost every brightening formula that avoids synthetic actives.
- Panthenol humectant
- Panthenol is pro-vitamin B5: skin converts it to pantothenic acid. It is a humectant that holds water and leaves skin feeling soft and less tight, and it is one of the ingredients formulators reach for when a formula also contains something harsh.
- Arginine amino acid
- Arginine is an amino acid that does two jobs here: it holds water in the outer layer of skin, and it neutralises acidic gelling agents, which is why it often stands in for a synthetic pH adjuster.
- Methyl Trimethicone silicone
- Methyl Trimethicone is a light, volatile silicone chosen for a notably dry finish. It thins a formula and disperses powders evenly.
- Allantoin active
- Allantoin is a comfrey-derived compound used to condition skin and soften the outer layer so it feels smoother. It is one of the standard additions to a formula built for easily irritated skin.
- Glutathione antioxidant
- Glutathione is a small peptide the body uses as one of its main antioxidants. In skincare it is used as an antioxidant and for the look of dullness; it is unstable in water, so formulas that carry it are usually built around protecting it.
- Sodium Acetylated Hyaluronate humectant
- Sodium Acetylated Hyaluronate is hyaluronic acid modified to be part oil-loving, so it clings to skin instead of rinsing away. Formulators call it the one that stays put.
- Market
- Korean market, the version sold in Korea
- EAN (barcode)
- 8809598454880
- Made in
- Republic of Korea
- Category
- Serum & Ampoule
- Actives
- Allantoin, Arbutin, Centella Asiatica, Glutathione, Hyaluronic Acid, Licorice Root, Madecassoside, Niacinamide, Panthenol, Sodium Hyaluronate, Tranexamic Acid
- Ships from
- California or Korea
Orders ship from California or direct from Korea with tracked delivery to your door, and both routes carry the same Korean-market release. Shipping is free on orders of $100 or more. Returns are accepted for 30 days, by mail.
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 - 2Barcode
Listed against the Korean barcode on its box - 3California or Korea
Ships to you from either, as the same Korean-market release
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. The barcode in the specification above is the Korean-market one and it is printed on the box you receive.
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.
Every order ships from California or direct from Korea, 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.
Key benefits
- Niacinamide and tranexamic acid lead the list ahead of the alpha-arbutin.
- Alpha-arbutin is declared at 2%, matching the name.
- Five hyaluronate and hyaluronic-acid entries round out the hydrating base.
- Madecassoside, licorice root extract and ferulic acid sit further down the list.
Inside the formula
Inside the formula
Reviews
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COSRX The Alpha-Arbutin 2 Discoloration Care Serum (Single)
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COSRX, Korean-market original
Alpha-Arbutin 2% discoloration serum (Single).
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.
Your skin barrier is basically your outer layer of the skin.
Melissa Piliang, MDDermatologist, 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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