Numbuzin
No.5+ Vitamin Concentrated Serum 30ml
Numbuzin No.5+ Vitamin Concentrated Serum 30ml carries three separate vitamin c forms on its own ingredient panel, including 3-0-Ethyl Ascorbic Acid, Ascorbic Acid, Ascorbyl Glucoside.
No reviews yet30 ml
$100.00 per 100 ml
- Korean-market formula
- Ships from California or direct from Korea
- Korean barcode and batch code intact
- Suited to
- normalcombinationdryoily
- Helps with
- tone and texture supported by Niacinamidedaily hydration through the serum stepa Korean-market formula rather than a US reformulationa routine step matched to this format
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
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How it works
The panel on this serum names three forms of vitamin c rather than one: 3-0-Ethyl Ascorbic Acid, Ascorbic Acid, Ascorbyl Glucoside. 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. On this panel it sits alongside Vaccinium Vitis-Idaea Fruit Extract, Niacinamide and Tranexamic Acid. Lingonberry fruit extract, a Nordic berry. It carries anthocyanins, arbutin and fruit acids, and it is used as an antioxidant botanical.
Key benefits
- Three forms of vitamin c on one panel, not a single token inclusion
- Vaccinium Vitis-Idaea Fruit Extract on the same panel, the formula's plant extract
- Niacinamide on the same panel, the formula's active
- 30 ml to a unit
- Korean GS1 barcode matched against a Korea sourcing supplier's record for this item
Inside the formula
Inside the formula
How do I know this is authentic and not a US-reformulated version?
Check the box against the listing: an authentic Korean-market SKU carries Korean-primary packaging and an intact Korean-market batch code, not a US-only relabel. Numbuzin's Korean-market formulas are sourced specifically to preserve that, rather than substituted for the US-shelf version some retailers carry under the same name.
When in a routine should I use this serum?
Use it as the serum step, AM and PM, after toner and before moisturizer. Placing a serum out of order is the most common reason a Korean routine feels like it is not working, so keep this one at its own step rather than doubling it up with a product built for a different stage. Give it a few weeks at that placement before judging the result.
Is this the same formula sold in Korea, or a US version?
This is sourced for the Korean market rather than reformulated for US shelves. Numbuzin sells a separate reformulation on some US shelves, and this listing is not that version. The Korean-market batch coding and packaging travel with it, which is the detail worth checking against the box on arrival.
What does Niacinamide do in this formula?
Niacinamide supports an even-looking skin tone and works alongside the formula's humectants to keep the surface comfortable. It is one of the most studied actives in Korean formulation for tone evenness and is gentle enough for daily AM and PM use. It sits at its own position on this product's own ingredient list rather than being assumed from the product name.
What does Panthenol do in this formula?
Panthenol is pro-vitamin B5, a conditioning agent Korean formulas lean on to keep the surface feeling soft rather than tight. It has a long track record in Korean skincare as a mild, everyday conditioning agent that layers cleanly under the rest of a routine. It sits at its own position on this product's own ingredient list rather than being assumed from the product name.
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 (47): Vaccinium Vitis-Idaea Fruit Extract, Butylene Glycol, Niacinamide, Panthenol, Tranexamic Acid, Water, 1,2-Hexanediol, Neopentyl Glycol Dicaprate, Caprylic/Capric Triglyceride, Sorbitol, Bifida Ferment Lysate, Chondrus Crispus Extract, Butyrospermum Parkii (Shea) Butter, Saccharum Officinarum (Sugarcane) Extract, Alpha-Arbutin, Sodium Hyaluronate, Melia Azadirachta Flower Extract, Ocimum Sanctum Leaf Extract, Melia Azadirachta Leaf Extract, Curcuma Longa Turmeric Root Extract, Corallina Officinalis Extract, Tremella Fuciformis (Mushroom) Extract, Pentylene Glycol, Glycerin, 3-0-Ethyl Ascorbic Acid, Bisabolol, Tromethamine, Ethylhexylglycerin, Adenosine, Hydrogenated Lecithin, Allantoin, Glutathione, Ceramide NP, Beta-Glucan, Dipotassium Glycyrrhizate, Tocopherol, Ascorbic Acid, Ascorbyl Glucoside, Tocopheryl Acetate, Hydroxypropyl Cyclodextrin, Ubiquinone, Thioctic Acid, Potassium Hydroxide, Behenyl Alcohol, Carbomer, Xanthan Gum, Disodium EDTA
Ingredient list read from incidecoder.com on 10 September 2026.
45 of 47 explained
- Vaccinium Vitis-Idaea Fruit Extract plant extract
- Lingonberry fruit extract, a Nordic berry. It carries anthocyanins, arbutin and fruit acids, and it is used as an antioxidant botanical.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- Neopentyl Glycol Dicaprate emollient
- A light branched ester with a dry, powdery finish. It is used to thin heavier oils without adding shine.
- 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.
- Sorbitol humectant
- Sorbitol is a sugar alcohol used as a humectant. It hydrates like glycerin with a smoother, less sticky finish, and it adds a little body to watery textures.
- Bifida Ferment Lysate ferment
- Bifida Ferment Lysate is a bifidobacteria ferment with the cells broken open. It is the ingredient behind the first-essence category and is used for the look of tired, reactive skin.
- Chondrus Crispus Extract plant extract
- Chondrus Crispus is Irish moss, a red seaweed. It is loaded with carrageenan, so it hydrates and thickens at once, and it leaves a cushioned, slippery film.
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- Butyrospermum Parkii (Shea) Butter emollient
- Shea Butter is the fat pressed from the shea nut, rich in oleic and stearic acids and unsaponifiable plant sterols. It is a heavy emollient and partial occlusive, which is why it sits in balms and night creams rather than in essences.
- Saccharum Officinarum (Sugarcane) Extract plant extract
- Sugarcane Extract carries natural glycolic acid and sugars. In cosmetics it is used as a humectant; the acid content is far too low to work as an exfoliant.
- Alpha-Arbutin 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.
- 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.
- Melia Azadirachta Flower Extract plant extract
- Melia Azadirachta is neem. Its leaf and flower extracts are long-standing Ayurvedic ingredients, and Korean formulas use them in products aimed at the look of congested, blemish-prone skin.
- Ocimum Sanctum Leaf Extract plant extract
- Ocimum Sanctum is holy basil, or tulsi. Its leaf extract carries plant antioxidants and is used in formulas built for the look of stressed, reactive skin.
- Corallina Officinalis Extract plant extract
- Corallina Officinalis is coral seaweed, which holds calcium and magnesium in its structure. Its extract is used as a mineral-rich conditioning ingredient.
- Tremella Fuciformis (Mushroom) Extract plant extract
- Tremella Fuciformis is snow mushroom. Its polysaccharide holds even more water than hyaluronic acid for its weight, which is why it appears in hydrating Korean formulas as a plant alternative.
- 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.
- 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.
- 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.
- Bisabolol active
- Bisabolol is the main active fraction of chamomile oil, usually supplied from candeia wood. It is used for the look of redness in formulas for reactive skin, and it helps other ingredients absorb.
- 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.
- 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.
- 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.
- 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.
- Ceramide NP barrier lipid
- Ceramide NP is the most used cosmetic ceramide, the same class of lipid that makes up roughly half the mortar between cells in the outer layer of skin. Added to a cream it slots into that structure, which is why ceramide formulas feel less leaky rather than merely greasy.
- Beta-Glucan polysaccharide
- Beta-Glucan is a polysaccharide from oats or yeast. It holds a large amount of water, forms a soothing film, and is one of the ingredients formulators reach for in products aimed at reactive skin.
- Dipotassium Glycyrrhizate active
- Dipotassium Glycyrrhizate is a water-soluble salt derived from licorice root. It is the licorice fraction Korean formulas use for the look of redness, and it is far more stable in water than the whole extract.
- 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.
- Ascorbic Acid antioxidant
- Ascorbic Acid is pure vitamin C, the most researched form and also the least stable: it needs a low pH and airtight packaging to stay active. It is an antioxidant used for the look of dullness and uneven tone.
- Ascorbyl Glucoside antioxidant
- Ascorbyl Glucoside is vitamin C bound to glucose, which keeps it stable until enzymes in skin release it. It is a mild, slow-release route to a vitamin C formula.
- Tocopheryl Acetate antioxidant
- Tocopheryl Acetate is a stable vitamin E ester that skin converts to tocopherol. It is used as an antioxidant and a light emollient and holds up better than plain vitamin E in a formula.
- Hydroxypropyl Cyclodextrin solvent
- Hydroxypropyl Cyclodextrin is a ring-shaped sugar that traps an active molecule inside itself, keeping it stable and releasing it slowly. It is a delivery shell rather than an active.
- Ubiquinone antioxidant
- Ubiquinone is coenzyme Q10, an antioxidant every cell uses in its own energy production. In a formula it is oil soluble, faintly yellow, and used for the look of tired, dull skin.
- Thioctic Acid antioxidant
- Thioctic Acid is alpha lipoic acid, an antioxidant that dissolves in both water and oil, which is unusual. It is yellow and carries a faint sulfur smell.
- Potassium Hydroxide pH adjuster
- Potassium Hydroxide is a strong base used in traces to raise a formula to its target pH. In a soap-style cleanser it also converts fatty acids into the surfactant that does the cleansing.
- Behenyl Alcohol fatty alcohol
- Behenyl Alcohol is a long-chain fatty alcohol used to thicken and stabilise a cream. It gives a richer, more velvety body than cetyl alcohol.
- 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.
- 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.
- 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.
- Market
- Korean market, the version sold in Korea
- EAN (barcode)
- 8809652581774
- Made in
- Republic of Korea
- Volume
- 30 ml
- Category
- Serum & Ampoule
- Actives
- Adenosine, Allantoin, Arbutin, Beta-Glucan, Bisabolol, Ceramide NP, Glutathione, Licorice Root, Niacinamide, Panthenol, Shea Butter, Sodium Hyaluronate, Tranexamic Acid, 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
- Apply after the toner while the skin is still damp so a small dose covers the face in one pass.
- Press it over the whole face rather than onto the marks only, since even tone needs even coverage.
- Always follow with a cream, because a concentrated layer left unsealed is where tightness comes from.
- Do not skip the morning sunscreen, since tone work without that last layer is undone faster than it is built.
Worth knowing
- Patch test on the inner arm first if trying a new brand's formula for the first time.
- Stop use and check the ingredient list against any known sensitivities before continuing.
Complete the routine
- This itemNumbuzin No.5+ Vitamin Concentrated Serum 30ml$30.00

- Prep after cleansing, before the treatment stepnumbuzin No.3 Bifida Bakuchiol Exfoliating Toner Pads 190ml/70ea$40.00

- The treatment step of this routinenumbuzin No.3 Bifida Bakuchiol Zero Pore Serum 30ml$47.50

Total for 3 items$117.50
Reviews
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numbuzin No.5+ Vitamin Concentrated Serum 30ml
How it felt, how your skin took it, what you layer it with. Straight answers help the next person choose.
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Numbuzin, Korean-market original
The Korean-market serum built around Niacinamide, from Numbuzin, sourced for the Korean market and reviewed before it ever reaches this page.
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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