Seoul 1988 Serum
K-Secret Seoul 1988 Serum is a 30ml serum with Niacinamide, used after toner and before moisturizer, morning and evening.
No reviews yet30 ml
$62.73 per 100 ml
- Korean-market formula
- Ships from California or direct from Korea
- Korean barcode and batch code intact
- Suited to
- Dry skinCompromised barrierDehydrated skinSensitive skin
- Helps with
- Shoppers looking for Niacinamide in a serumRoutines that want Niacinamide and Adenosine in one stepFilling the serum step with a Korean-market formula
In stock. Arrives in 3 to 7 business days
We accept
You’re $100.00 away from free US shipping.
- 30-day returns
- Free US shipping on orders of $100 or more
- Tracked delivery to your door
How it works
The Seoul 1988 Serum is a 30ml serum, used after toner and before moisturizer, morning and evening. The active it is built around is Niacinamide, named seventh on its own ingredient list. The same list carries Adenosine, Retinal and Bakuchiol, so the active is not the only thing on it worth naming. How much of the Niacinamide stays on the skin, and for how long, is decided by the serum format rather than by the list alone. K-Secret sells this Niacinamide serum in Korea, and this is that version.
Key benefits
- Niacinamide, the active this serum is built around
- Adenosine, Retinal and Bakuchiol on the same list, actives
- sh-Oligopeptide-1 on the same list, a peptide
- sh-Oligopeptide-2 and Tocopherol further down the same list
- Pentaerythrityl Tetra-di-t-butyl Hydroxyhydrocinnamate and 3-O-Ethyl Ascorbic Acid further down the same list
- Niacinamide named seventh on the manufacturer list printed on this page
Inside the formula
Inside the formula
Where does this serum go in my routine?
After toner and before moisturizer, morning and evening. Anything thinner than a serum goes on before it, and anything richer goes on after. If you are adding it to a routine you already like, give it a week on its own first, so what you see is the Niacinamide and not three changes at once.
What else is on the list besides Niacinamide?
Adenosine, Retinal and Bakuchiol. The order they are printed in on this serum's panel is the order on the box, so you can see where Niacinamide sits relative to them. Further down the same panel: sh-Oligopeptide-1, sh-Oligopeptide-2 and Tocopherol.
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 (41): Panax Ginseng Root Extract, Water, Glycerin, Dipropylene Glycol, Caprylic/Capric Triglyceride, 1,2-Hexanediol, Niacinamide, Butylene Glycol, Methyl Gluceth-20, Polyglyceryl-3 Methylglucose Distearate, Hydrogenated Lecithin, Sorbitan Stearate, Ammonium Acryloyldimethyltaurate/VP Copolymer, Macadamia Ternifolia Seed Oil, Carbomer, Tromethamine, Betaine, Tocopherol, Ethylhexylglycerin, Helianthus Annuus (Sunflower) Seed Oil, Adenosine, Disodium EDTA, Cholesterol, Polyglyceryl-10 Oleate, Brassica Campestris (Rapeseed) Sterols, Phytosteryl/Behenyl/Octyldodecyl Lauroyl Glutamate, Retinal, Silica, Aluminum/Magnesium Hydroxide Stearate, Potassium Cetyl Phosphate, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Arctium Lappa Root Extract, Cnidium Officinale Root Extract, Dioscorea Japonica Root Extract, Paeonia Suffruticosa Root Extract, Rehmannia Chinensis Root Extract, 3-0-Ethyl Ascorbic Acid, Bakuchiol, SH-Oligopeptide-1, SH-Oligopeptide-23 Sp, Polypeptide-1
Ingredient list read from inkeedecoder.com on 10 September 2026.
39 of 41 explained
- Panax Ginseng Root Extract plant extract
- Ginseng Root Extract is the signature ingredient of Korean traditional skincare, carrying ginsenosides. It is used for the look of tired, dull skin, and brands often ferment it to break the ginsenosides into smaller forms.
- 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.
- 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.
- 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.
- Caprylic/Capric Triglyceride emollient
- Caprylic/Capric Triglyceride is the light fraction of coconut oil, with the heavy parts removed. It is the workhorse emollient of modern formulas: it softens skin, dissolves oil-soluble actives and absorbs without the greasy weight of a whole plant oil.
- 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.
- 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.
- Methyl Gluceth-20 humectant
- Methyl Gluceth-20 is a sugar-derived humectant. It holds water in the outer layer of skin and gives a smooth, cushioned slip that plain glycerin does not.
- Polyglyceryl-3 Methylglucose Distearate emulsifier
- Polyglyceryl-3 Methylglucose Distearate is a sugar-derived emulsifier known for a light, non-soapy feel. It builds gel-creams that do not read as rich.
- 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.
- Sorbitan Stearate emulsifier
- Sorbitan Stearate is a mild emulsifier and thickener used to hold oil and water together in creams.
27 more explained
- 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.
- Macadamia Ternifolia Seed Oil emollient
- Macadamia Seed Oil is unusually high in palmitoleic acid, a fatty acid that human sebum also contains, which is why it absorbs faster than most nut oils. It is a cushioning emollient for dry skin.
- Carbomer thickener
- Carbomer is a synthetic polymer that only gels once a base neutralises it, which is why arginine or tromethamine sits nearby on the list. It gives the clear, non-stringy gel texture a xanthan formula cannot reach.
- Tromethamine pH adjuster
- Tromethamine neutralises acidic thickeners such as carbomer so they gel, and holds a formula near skin-friendly pH. It is used at a fraction of a percent.
- 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.
- 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.
- 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.
- Helianthus Annuus (Sunflower) Seed Oil emollient
- Sunflower Seed Oil is high in linoleic acid, the fatty acid dry and blemish-prone skin is often short of. It is a light, non-fragrant emollient and one of the better tolerated plant oils.
- 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.
- 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.
- Cholesterol barrier lipid
- Cholesterol is the third of the three lipids the outer layer of skin is built from, with ceramides and fatty acids. Formulas that carry all three are following the ratio skin itself holds.
- Polyglyceryl-10 Oleate emulsifier
- Polyglyceryl-10 Oleate is a mild sugar-derived emulsifier and solubiliser used where a formula must stay clear.
- Brassica Campestris (Rapeseed) Sterols emollient
- Phytosterols are plant sterols, structurally close to the cholesterol in skin's own lipid layer. They soften skin and help the oil phase of a formula hold together.
- Phytosteryl/Behenyl/Octyldodecyl Lauroyl Glutamate barrier lipid
- An amino-acid-based lipid built on plant sterols. It structures the oil phase of a cream and echoes the lipid mix that already sits between skin cells.
- Retinal active
- Retinal is retinaldehyde, a vitamin A derivative one chemical step closer to retinoic acid than retinol is. It is yellow-orange and unstable in light, so products carrying it are usually opaque.
- Silica absorbent
- Silica is finely milled mineral, essentially very pure sand. It absorbs oil, stops powders clumping and soft-focuses the look of pores and fine lines.
- Aluminum/Magnesium Hydroxide Stearate dispersant
- A mineral soap used to suspend powders and thicken an oil phase, which is what stops pigment settling to the bottom of a bottle.
- Potassium Cetyl Phosphate emulsifier
- Potassium Cetyl Phosphate is an emulsifier prized for keeping powdered ingredients evenly suspended, which is why tinted and mineral-powder textures use it.
- Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate antioxidant
- This is a stabiliser that keeps the oils and fragrance in a formula from oxidising. Its job is the shelf life of the product rather than any effect on skin.
- Arctium Lappa Root Extract plant extract
- Burdock root extract, the ueong eaten in Korea. It carries inulin and polyphenols and is used as a conditioning extract.
- Cnidium Officinale Root Extract plant extract
- Cheongung, a traditional Korean medicinal root from the carrot family. Its extract is used as a conditioning plant extract.
- Dioscorea Japonica Root Extract plant extract
- Dioscorea Japonica is Japanese wild yam, whose root is naturally slippery with mucilage. Its extract hydrates and leaves a cushioned feel.
- Paeonia Suffruticosa Root Extract plant extract
- Paeonia Suffruticosa is tree peony, a long-standing East Asian medicinal plant. Its root extract carries paeoniflorin and is used for the look of reddened skin.
- Rehmannia Chinensis Root Extract plant extract
- Rehmannia root extract, one of the most used roots in East Asian herbal practice. It carries catalpol and sugars, so it also brings a little water holding character.
- 3-0-Ethyl Ascorbic Acid antioxidant
- 3-O-Ethyl Ascorbic Acid is a stable vitamin C derivative that skin converts to ascorbic acid. It survives in a formula far better than pure vitamin C and works at a gentler pH, so it suits skin that finds the pure acid uncomfortable.
- Bakuchiol active
- Bakuchiol is a compound from the babchi seed, used as a plant-derived alternative to retinol. It is oil soluble, stable in daylight and does not carry retinol's acclimatisation period, which is why sensitive-skin formulas choose it.
- SH-Oligopeptide-1 peptide
- sh-Oligopeptide-1 is a peptide made by yeast fermentation rather than synthesis, which is what the sh prefix records. It is used for the look of firmness and skin recovery after irritation.
- Market
- Korean market, the version sold in Korea
- EAN (barcode)
- 8809695240508
- Made in
- Republic of Korea
- Volume
- 30 ml
- Category
- Serum & Ampoule
- Actives
- Adenosine, Bakuchiol, Ginseng, Niacinamide, Peptides, Vitamin C
- 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.
How to use
- After toner, AM and/or PM. Press or smooth over the face and let it settle before the next step.
Worth knowing
- Patch test this serum on a small area and wait a day before using it more widely, especially with Niacinamide on the list.
- Retinal is on this list, so keep this serum to the evening and build the nights up slowly rather than starting nightly.
Complete the routine
- This itemK-Secret Seoul 1988 Serum$18.82

- Seal the routine in as the last stepK-SECRET SEOUL 1988 Cream : Snail Mucin 93% + Rice 100ml$50.00

- From the same Korean-market lineK-Secret Advanced Regenerating Eye Gel Patches$19.99

Total for 3 items$88.81
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K-Secret Seoul 1988 Serum
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K-Secret, Korean-market original
The Original Korean Formula serum from K-Secret, 30ml formulated with Niacinamide and Adenosine, shipped from California or direct from Korea.
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.
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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