The 6 Peptide Skin Booster Serum
COSRX's six-peptide booster serum, layering niacinamide with copper tripeptide-1 and sh-Polypeptide-121, worn after toner and before moisturizer, morning and evening.
No reviews yet150ml
$16.66 per 100 ml
- Korean-market formula
- Ships from California or direct from Korea
- Korean barcode and batch code intact
- Suited to
- MatureFine linesSensitiveCompromised barrier
- Helps with
- Fine lines and loss of bounceBarrier weaknessDehydrationEarly environmental damage
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- 30-day returns
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- Tracked delivery to your door
How it works
A booster serum is something you add to a routine that already works, and the name here is the idea: peptides, in a light water-based fluid. It goes on after toner and before moisturizer, morning and evening, pressed in with flat palms on damp skin. Skin that looks tired and flat by the evening is the case it fits, and peptide work is cumulative rather than overnight. It layers under anything else already in the routine, which is what a booster is for. Twice a day, every day, on the neck as well as the face.
Key benefits
- Six named peptides run back to back at entries seven through twelve, exactly matching the count in the product name
- Niacinamide leads directly into the peptide stack at entry six
- Allantoin and sodium hyaluronate cushion the peptide stack immediately behind it
- Lightweight, fast-absorbing texture built to layer, not to replace a heavier step
- COSRX runs its own brand-portal verification: enter the batch number and expiry from your unit on cosrx.com
- Sourced for the Korean market, Korean barcode 8809598455658 intact on the box
COSRX The 6 Peptide Skin Booster Serum
What are the six peptides in this booster serum and where do they sit on the list?
Six named peptides run back to back at entries seven through twelve: acetyl hexapeptide-8, copper tripeptide-1, sh-polypeptide-121, dipeptide diaminobutyroyl benzylamide diacetate, oligopeptide-68 and palmitoyl tripeptide-8. Niacinamide leads directly into that run at entry six, and adenosine appears further down the list as an additional actives layer. The count in the product's name matches the count of distinct peptide ingredients actually on the label.
Is a peptide serum like this suitable for sensitive or first-time peptide users?
The ingredient list contains no fragrance, essential oil, silicone, paraben, sulfate surfactant, mineral oil or added colourant, which is a relatively low-irritation profile for a first peptide product. Allantoin and sodium hyaluronate sit near the peptide stack for comfort and hydration, and a wide amino acid set rounds out the formula. Peptides themselves are not typically irritating, but as with any new step, introducing it gradually is the safer approach.
How long does it take to see a difference from a peptide serum?
Peptides work by supporting skin's ongoing processes rather than producing an immediate visible change, so the honest expectation is weeks of consistent use before firmness or texture reads differently. Niacinamide, positioned just ahead of the peptide stack, tends to show its evening effect on a similar timeline. Using the serum inconsistently will simply slow that timeline rather than causing harm.
Can this peptide serum be layered under a retinoid or brightening product?
This serum's list is built from peptides, amino acids and humectants, with nothing that would inherently conflict with a separate retinoid or brightening step used elsewhere. A common approach is to apply this serum first on clean skin, let it settle, then follow with a treatment product and moisturizer. Confirm the exact order against whatever other product's own instructions you are using.
How do I know my bottle is the genuine Korean-market version of this serum?
The barcode on this unit, 8809598455658, is the original Korean-market code, kept intact rather than covered by a domestic sticker. COSRX verifies units through its own system: locate the batch-check page on cosrx.com and enter the batch number and expiration date exactly as printed on your box, since reading those numbers directly off your own unit rather than trusting a seller's claim is the whole point of that check.
Not on the ingredient list below: fragrance or parfum, denatured or SD alcohol, essential oils, silicones, parabens, sulfate surfactants, mineral oil or petrolatum and added color.
Full INCI (44): Water, Dipropylene Glycol, Glycerin, Pentylene Glycol, 1,2-Hexanediol, Niacinamide, Acetyl Hexapeptide-8, Copper Tripeptide-1, sh-Polypeptide-121, Dipeptide Diaminobutyroyl Benzylamide Diacetate, Oligopeptide-68, Palmitoyl Tripeptide-8, Allantoin, Sodium Hyaluronate, Acetyl Glucosamine, Serine, Alanine, Glycine, Threonine, Arginine, Proline, Betaine, Sodium PCA, Sodium Lactate, PCA, Glutamic Acid, Lysine HCl, Tocopherol, Dextran, Glycine Soja (Soybean) Oil, Hydrogenated Lecithin, Ammonium Acryloyldimethyltaurate/VP Copolymer, Polyacrylate Crosspolymer-6, Butylene Glycol, Xanthan Gum, Ethylhexylglycerin, Adenosine, Polyquaternium-51, Disodium EDTA, Citric Acid, Caprylyl Glycol, t-Butyl Alcohol, Potassium Sorbate, Sodium Oleate
Ingredient list read from jolse.com on 9 September 2026.
44 of 44 explained
- 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.
- Dipropylene Glycol humectant
- Dipropylene Glycol is a glycol used as a solvent and a light humectant. Its main job is keeping the rest of the formula dissolved and the texture fluid rather than adding hydration of its own.
- 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.
- Pentylene Glycol humectant
- Pentylene Glycol hydrates and, like the other longer-chain glycols, makes a formula less hospitable to microbes so the preservative system can be lighter. It also improves how evenly a product spreads.
- 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.
- 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.
- Acetyl Hexapeptide-8 peptide
- Acetyl Hexapeptide-8 is a six-amino-acid peptide used for the look of expression lines, particularly around the eyes. It is the peptide sold under the name Argireline and is water soluble and stable.
- Copper Tripeptide-1 peptide
- Copper Tripeptide-1 is three amino acids bound to a copper ion, and the classic firming peptide in cosmetic chemistry. It is blue in solution, which is often why a serum carrying it is tinted, and it is used for the look of firmness and fine lines.
- sh-Polypeptide-121 peptide
- A fermentation-produced polypeptide. Korean formulas group these sh-polypeptides together as a conditioning peptide complex rather than using one alone.
- Dipeptide Diaminobutyroyl Benzylamide Diacetate peptide
- This is a two-amino-acid peptide, sold as Syn-Ake, used for the look of expression lines. Its structure was modelled on a component of snake venom, though nothing of the venom itself is in it.
- Oligopeptide-68 peptide
- A short amino acid chain used for the look of uneven tone. It is the oligopeptide most often paired with niacinamide in brightening formulas.
- Palmitoyl Tripeptide-8 peptide
- A three-amino-acid peptide with a palmitic acid tail, which lets it sit in the oil phase. It is used for the look of reddened, reactive skin.
32 more explained
- 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.
- 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.
- 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.
- Serine amino acid
- Serine is one of the most abundant free amino acids in the outer layer of skin, where it helps hold water. Added to a formula it is a humectant.
- Alanine amino acid
- Alanine is a free amino acid skin uses as part of its own moisture-holding system. In a formula it hydrates and conditions.
- Glycine amino acid
- Glycine is the smallest amino acid and one of the free amino acids skin holds to keep water in the outer layer. In a formula it is a humectant and a mild buffer.
- Threonine amino acid
- Threonine is an essential amino acid used in skincare as a humectant, normally as part of an amino acid complex rather than alone.
- 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.
- Proline amino acid
- Proline is an amino acid abundant in collagen and one of skin's own humectants. Added to a formula it holds water in the outer layer.
- Betaine humectant
- Betaine is a sugar-beet-derived humectant that cells use to hold water. In a formula it hydrates and takes the edge off cleansers and acids, which is why it often appears alongside them.
- Sodium PCA humectant
- Sodium PCA is one of the substances skin makes for itself to hold water, part of what dermatology calls the natural moisturising factor. Added to a formula it is a strong humectant that suits skin that dehydrates quickly.
- Sodium Lactate humectant
- Sodium Lactate is the salt of lactic acid and one of the components of skin's own natural moisturising factor. At the levels used here it is a humectant and buffer rather than an exfoliant.
- PCA humectant
- PCA is pyrrolidone carboxylic acid, one of the components of the natural moisturising factor skin makes for itself. It holds water at the surface, and its salts do the same job.
- Glutamic Acid amino acid
- Glutamic Acid is an amino acid used as a humectant and a mild pH adjuster. It is one of the components of skin's natural moisturising factor.
- Lysine HCl amino acid
- Lysine is an essential amino acid, here as its hydrochloride salt for solubility. Amino acids on a label hold water and condition the surface.
- 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.
- Dextran polysaccharide
- Dextran is a branched sugar polymer made by fermenting sucrose. It holds water, thickens slightly, and is used as a carrier that keeps other water-soluble ingredients evenly spread.
- Glycine Soja (Soybean) Oil emollient
- Soybean Oil is a linoleic-rich plant oil used as an emollient. It also carries soy phytosterols and vitamin E.
- 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.
- Ammonium Acryloyldimethyltaurate/VP Copolymer thickener
- This is a synthetic thickener that gels quickly and holds an emulsion stable across a wide pH range. It gives a light, non-tacky body.
- Polyacrylate Crosspolymer-6 thickener
- Polyacrylate Crosspolymer-6 is a thickener chosen for a notably fresh, bouncy gel feel that breaks down to water on the skin.
- 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.
- 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.
- 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.
- Adenosine active
- Adenosine is a nucleoside that Korea's own cosmetic authority recognises as a wrinkle-care functional ingredient, which is why it appears on so many Korean lists at a low level. It is used for the look of fine lines and is stable and well tolerated.
- Polyquaternium-51 film former
- Polyquaternium-51 is a polymer, sometimes sold as Lipidure, built on the same phosphorylcholine structure as a cell membrane. It holds water in a film on the surface and gives a distinctive soft, dry finish.
- 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.
- 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.
- Caprylyl Glycol preservative booster
- Caprylyl Glycol is a glycol that conditions skin and, more importantly, strengthens a preservative system so less of the traditional preservative is needed. It appears in most modern formulas built without parabens.
- t-Butyl Alcohol solvent
- t-Butyl Alcohol is the bittering agent added to cosmetic ethanol so it cannot be drunk. It appears in tiny amounts alongside alcohol denat. and does no formulation work of its own.
- Potassium Sorbate preservative
- Potassium Sorbate is a preservative that holds off yeast and mould in acidic formulas. It is almost always used with sodium benzoate, because neither covers the whole range of microbes alone.
- Sodium Oleate surfactant
- Sodium Oleate is the soap made from oleic acid. It cleanses and foams, and it is what a cleansing balm turns into when the oil phase is saponified.
- Market
- Korean market, the version sold in Korea
- EAN (barcode)
- 8809598455658
- Made in
- Republic of Korea
- Volume
- 150ml
- Category
- Serum & Ampoule / Peptide serum / skin booster
- Actives
- Adenosine, Allantoin, Niacinamide, Peptides, Sodium Hyaluronate
- 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.
Inside the formula
Inside the formula
How to use
- Use the 6 Peptide Skin Booster Serum after toner and before moisturizer, morning and evening.
- Three or four drops for the face and neck, pressed in with flat palms rather than rubbed around.
- Toner first, this second, then moisturizer over the top, and sunscreen last in the morning.
- Twice a day, every day. Do not swap it in for your moisturizer; a booster is a layer under one rather than a replacement for it.
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COSRX The 6 Peptide Skin Booster Serum
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COSRX, Korean-market original
6 Peptide skin booster serum, 150 ml, with Niacinamide.
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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