COSRX Advanced The Vitamin C 23 Serum bottle featuring Super Vitamin E and Hyaluronic Acid; high-potency 23% stabilized Vitamin C formulation designed to brighten dull skin, refine pores, and even skin tone while hydrating; minimal modern K-beauty packaging emphasizing clinical-grade clarity and gentle brightening care.
COSRX Advanced The Vitamin C 23 Serum displayed on an icy blue background with clinical proof badges for non-comedogenic, antioxidant, and clinically proven results; formulated with 23% pure Vitamin C to visibly improve tone, glow, and texture while reducing dark spots and refining pores.
Updated COSRX Advanced The Vitamin C 23 Serum dropper shown releasing golden drops; upgraded dual-layer formula with Super Vitamin E and Hyaluronic Acid offers stronger clinical efficacy, brightening dark spots, and smoothing rough texture for luminous, even skin tone.
COSRX Advanced The Vitamin C 23 Serum clinical results infographic showing 100% improvement in brightness, firmness, texture refinement, and skin transparency; proven to make skin clearer and smoother after consistent use, reducing dullness and fine lines with visible tone-evening benefits.
Clinically proven COSRX Advanced The Vitamin C 23 Serum bottle held in hand, highlighting benefits including antioxidant action, pigmentation reduction, refined pores, improved texture, and radiance; validated by Dermacosmetic Skin Science Lab for clearer, brighter, and firmer skin.
Set of COSRX Advanced The Vitamin C 23 Serum bottles with golden background highlighting 23% pure Vitamin C, antioxidant synergy for early-aging prevention, and dual-layer hydration; designed to visibly brighten tone, smooth texture, and reduce hyperpigmentation and pore appearance.
Visual of pure ascorbic acid droplets representing the key ingredient in COSRX Advanced The Vitamin C 23 Serum; high-concentration Vitamin C delivers antioxidant, brightening, and firming benefits, helping even skin tone, fade dark spots, and restore healthy glow.
Before-and-after photos from COSRX Advanced The Vitamin C 23 Serum clinical study showing visible reduction in blemishes and pigmentation after 4 weeks; results include -17.43% surface pigmentation and +5.02% tone improvement, backed by Dermacosmetic Skin Science Lab testing.
COSRX Advanced The Vitamin C 23 Serum clinical data showing +92.32% improvement in skin texture and +34.81% radiance and brightening; proven to reduce redness by 30.14% and enhance clarity, offering smoother, even-toned, luminous skin through stabilized Vitamin C care.
Golden liquid illustration featuring COSRX Advanced The Vitamin C 23 Serum dropper with antioxidant synergy callouts; highlights hydration, soothing, firmness, and brightening benefits for early-aging prevention and texture improvement through 23% pure Vitamin C and Vitamin E blend.
COSRX Advanced The Vitamin C 23 Serum ingredient chart showing antioxidant synergy with Vitamin E, Tocopherol, and Glutathione; firmness and brightening benefits with Adenosine and Niacinamide; and moisture-soothing blend with Panthenol, Hyaluronic Acid, and Allantoin for radiant, even-toned skin.
Clinically proven COSRX Advanced The Vitamin C 23 Serum demonstrated -12.16% wrinkle reduction around eyes and improved elasticity up to -15.07%; shown applied by model with luminous skin, highlighting serum’s ability to firm, smooth, and refine early-aging texture.
Before-and-after clinical comparison showing visible pore reduction after 4 weeks of using COSRX Advanced The Vitamin C 23 Serum; results include -38.15% pore volume and -36.05% pore area, improving firmness, texture smoothness, and evenness of skin tone.
Visual breakdown of COSRX Pure Vitamin C features, real pure Vitamin C, 23% high concentration, and optimal pH balance, ensuring fast antioxidant benefits, brightening results, and stabilized efficacy for comfortable, irritation-free use on sensitive skin.
Illustration of COSRX Advanced The Vitamin C 23 Serum’s antioxidant action showing golden Vitamin C molecules protecting skin layers from oxidative stress; clinically proven to defend against daily environmental damage and promote youthful radiance and smooth texture.
Close-up of COSRX Advanced The Vitamin C 23 Serum dropper with golden dual-layered formula; stabilized oil and water layers designed to minimize skin burden while delivering a soft, bouncy finish that hydrates and refines skin texture.
COSRX Advanced The Vitamin C 23 Serum bottle shown under frosted glass highlighting its non-comedogenic and sensitive skin irritation-tested formula; gentle derma-grade serum providing brightening and pore-refining results without redness or discomfort.
COSRX Advanced The Vitamin C 23 Serum packaging breakdown with gas-controlling cap, oxidation-preventing container, and hygienic dropper; specialized K-beauty design maintaining 23% pure Vitamin C freshness and stability for consistent tone-brightening results.
Comparison chart between COSRX Vitamin C 13 Serum for daily brightening and COSRX Advanced The Vitamin C 23 Serum for intensive antioxidant care; emphasizes dual-layer nourishment, higher concentration, and visible dark spot fading benefits.
Step-by-step visual guide showing application of COSRX Advanced The Vitamin C 23 Serum; instructions include refrigerating after opening, shaking lightly, and applying a few drops post-toner for optimal brightening, texture improvement, and pore refinement.
Top-Fave Renewal
COSRX Advanced The Vitamin C 23 Serum bottle featuring Super Vitamin E and Hyaluronic Acid; high-potency 23% stabilized Vitamin C formulation designed to brighten dull skin, refine pores, and even skin tone while hydrating; minimal modern K-beauty packaging emphasizing clinical-grade clarity and gentle brightening care.
COSRX Advanced The Vitamin C 23 Serum displayed on an icy blue background with clinical proof badges for non-comedogenic, antioxidant, and clinically proven results; formulated with 23% pure Vitamin C to visibly improve tone, glow, and texture while reducing dark spots and refining pores.
Updated COSRX Advanced The Vitamin C 23 Serum dropper shown releasing golden drops; upgraded dual-layer formula with Super Vitamin E and Hyaluronic Acid offers stronger clinical efficacy, brightening dark spots, and smoothing rough texture for luminous, even skin tone.
COSRX Advanced The Vitamin C 23 Serum clinical results infographic showing 100% improvement in brightness, firmness, texture refinement, and skin transparency; proven to make skin clearer and smoother after consistent use, reducing dullness and fine lines with visible tone-evening benefits.
Clinically proven COSRX Advanced The Vitamin C 23 Serum bottle held in hand, highlighting benefits including antioxidant action, pigmentation reduction, refined pores, improved texture, and radiance; validated by Dermacosmetic Skin Science Lab for clearer, brighter, and firmer skin.
Set of COSRX Advanced The Vitamin C 23 Serum bottles with golden background highlighting 23% pure Vitamin C, antioxidant synergy for early-aging prevention, and dual-layer hydration; designed to visibly brighten tone, smooth texture, and reduce hyperpigmentation and pore appearance.
Visual of pure ascorbic acid droplets representing the key ingredient in COSRX Advanced The Vitamin C 23 Serum; high-concentration Vitamin C delivers antioxidant, brightening, and firming benefits, helping even skin tone, fade dark spots, and restore healthy glow.
Before-and-after photos from COSRX Advanced The Vitamin C 23 Serum clinical study showing visible reduction in blemishes and pigmentation after 4 weeks; results include -17.43% surface pigmentation and +5.02% tone improvement, backed by Dermacosmetic Skin Science Lab testing.
COSRX Advanced The Vitamin C 23 Serum clinical data showing +92.32% improvement in skin texture and +34.81% radiance and brightening; proven to reduce redness by 30.14% and enhance clarity, offering smoother, even-toned, luminous skin through stabilized Vitamin C care.
Golden liquid illustration featuring COSRX Advanced The Vitamin C 23 Serum dropper with antioxidant synergy callouts; highlights hydration, soothing, firmness, and brightening benefits for early-aging prevention and texture improvement through 23% pure Vitamin C and Vitamin E blend.
COSRX Advanced The Vitamin C 23 Serum ingredient chart showing antioxidant synergy with Vitamin E, Tocopherol, and Glutathione; firmness and brightening benefits with Adenosine and Niacinamide; and moisture-soothing blend with Panthenol, Hyaluronic Acid, and Allantoin for radiant, even-toned skin.
Clinically proven COSRX Advanced The Vitamin C 23 Serum demonstrated -12.16% wrinkle reduction around eyes and improved elasticity up to -15.07%; shown applied by model with luminous skin, highlighting serum’s ability to firm, smooth, and refine early-aging texture.
Before-and-after clinical comparison showing visible pore reduction after 4 weeks of using COSRX Advanced The Vitamin C 23 Serum; results include -38.15% pore volume and -36.05% pore area, improving firmness, texture smoothness, and evenness of skin tone.
Visual breakdown of COSRX Pure Vitamin C features, real pure Vitamin C, 23% high concentration, and optimal pH balance, ensuring fast antioxidant benefits, brightening results, and stabilized efficacy for comfortable, irritation-free use on sensitive skin.
Illustration of COSRX Advanced The Vitamin C 23 Serum’s antioxidant action showing golden Vitamin C molecules protecting skin layers from oxidative stress; clinically proven to defend against daily environmental damage and promote youthful radiance and smooth texture.
Close-up of COSRX Advanced The Vitamin C 23 Serum dropper with golden dual-layered formula; stabilized oil and water layers designed to minimize skin burden while delivering a soft, bouncy finish that hydrates and refines skin texture.
COSRX Advanced The Vitamin C 23 Serum bottle shown under frosted glass highlighting its non-comedogenic and sensitive skin irritation-tested formula; gentle derma-grade serum providing brightening and pore-refining results without redness or discomfort.
COSRX Advanced The Vitamin C 23 Serum packaging breakdown with gas-controlling cap, oxidation-preventing container, and hygienic dropper; specialized K-beauty design maintaining 23% pure Vitamin C freshness and stability for consistent tone-brightening results.
Comparison chart between COSRX Vitamin C 13 Serum for daily brightening and COSRX Advanced The Vitamin C 23 Serum for intensive antioxidant care; emphasizes dual-layer nourishment, higher concentration, and visible dark spot fading benefits.
Step-by-step visual guide showing application of COSRX Advanced The Vitamin C 23 Serum; instructions include refrigerating after opening, shaking lightly, and applying a few drops post-toner for optimal brightening, texture improvement, and pore refinement.

Advanced The Vitamin C 23 Serum

Power-Brightening Pure Vitamin C Serum

COSRX’s Advanced The Vitamin C 23 Serum features a high strength 23% pure vitamin C with Super Vitamin E and Glutathione to target uneven skin tone, early signs of aging, and dullness. Ideal for experienced vitamin C users seeking visible brightening and firmer skin, it absorbs smoothly to leave the complexion more radiant, supple, and revitalized.

Size: 20ml / 0.67fl. oz

$25.00
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Concerns & Benefits
Concern Suitable Key Benefit Key Ingredient
Dull & uneven tone Yes Brightens and evens tone Vitamin C (23%)
Dark spots & post-breakout marks Yes Helps dark spot care Vitamin C + Niacinamide
Fine lines & early aging Yes Early signs of aging care Vitamin C + Hyaluronic Acid
Dryness Yes Refines and smooths surface Vitamin C + Allantoin
Lack of radiance Yes Restores healthy glow Vitamin C + Super Vitamin E + Glutathione
How to Use
  1. After cleansing and toning, apply 2–3 drops to the entire face.
  2. Pat gently for better absorption.
  3. Follow with moisturizer and SPF during the day.

*Cautions*
As this product contains a high concentration of Vitamin C, we recommend avoiding use alongside Copper Peptide products, including our Blue Peptide Serum & Cream, as well as other high-concentration actives such as retinol. For best results, use them at different times of day (morning/evening) to optimize absorption and maximize the benefits of each product.

Product Fact Pack
Info Details
Volume 20g
Key Ingredients Pure Vitamin C 23%, Super Vitamin E, Glutathione, Adenosine, Niacinamide(B3), Allantoin, Panthenol(B5), Hyaluronic Acid
Clinically Proven Yes (Non comedogenic Test, Sensitive skin irritation test, Primary skin irritation test)
Expiration 24 months from the date of manufacture or 2 months after opening
Allergens Hypoallergenic tested
Why COSRX?
Feature Vitamin C 23 Serum Typical Vitamin C Serum
Vitamin C strength 23% pure vitamin C + Super Vitamin E + Glutathione Lower % or less potent formula
Target concerns Brightening dull skin, reducing wrinkles, improving elasticity Only address one or two concerns
Texture / layering Layers of oil + serum, smooth finish Heavier or single phase
Usage caution / suitability Requires care (storage, usage) due to high potency More everyday/basic formula

Clinically formulated to deliver higher potency, improved elasticity, and multi-layer hydration beyond standard Vitamin C serums. Tested by P&K Skin Research Center Co., Ltd and Dermacosmetic Skin Science Laboratory (Korea).

Ingredient List
Aqua/Water, Ascorbic Acid(23%), Butylene Glycol, Dimethicone, Panthenol, 3-O-Ethyl Ascorbic Acid, Squalane, Sodium Hydroxide, Caffeine, Sodium Hyaluronate, Sodium Metaphosphate, Adenosine, Acetyl Glucosamine, Gardenia Florida Fruit Extract, Allantoin, Dextrin, Tocotrienols, Tocopherol, Elaeis Guineensis (Palm) Oil, Arginine, Niacinamide, Pentylene Glycol, Glutathione, Helianthus Annuus (Sunflower) Seed Oil, Methyl Trimethicone, Carthamus Tinctorius (Safflower) Seed Oil, Camellia Japonica Seed Oil, Daucus Carota Sativa (Carrot) Root Extract, Glycyrrhiza Glabra (Licorice) Root Extract, Beta-Carotene
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More details Right
BUSTLE BEAUTY AWARDS WINNER

Achieve Youthful & Radiant Skin

The freshest and safest pure vitamin C

Brightening. slow-aging. Smoothing. Revitalizing. Pore-refining.  
Close-up of COSRX Advanced The Vitamin C 23 Serum bottle with dropper dispensing golden formula; high-potency Vitamin C enriched with Vitamin E and Hyaluronic Acid to enhance skin clarity, target hyperpigmentation, and improve firmness and radiance.
Model showcasing glowing complexion while holding COSRX Advanced The Vitamin C 23 Serum; formulated with 23% pure Vitamin C to visibly even skin tone, fade dark spots, and refine pores, offering a luminous, makeup-ready finish and smooth skin texture.
#HIGH-CONCENTRATION #Brightening #PUREVITAMINC

Brighter, Firmer, Clearer in Just 4 Weeks

Based on a 4-week clinical study conducted by Dermacosmetic Skin Science Lab, Korea.

+34.81%

improvement in radiance & brightening

+92.32%

improvement in skin texture

-30.14%

reduction in redness

-17.43%

decrease in pigmentation area

+15.07%

increase in skin elasticity

All clinical studies were conducted by Dermacosmetic Skin Science Laboratory(Korea) from May 3 to June 30, 2025, on 20 adult participants.

WHO IS IT FOR?

Perfect for those already familiar with Vitamin C who want upgrade to a high potency formula for faster and more visible results.

Ideal for dull, tired, or uneven skin, targeting lack of lack of radiance and uneven tone to reveal a brighter, more refined complexion with every use.

Best for those concerned with early signs of aging, including fine lines, loss of elasticity, and rough texture.

Ideal as a targeted solution for dark spots, pigmentation, or stubborn blemish marks that need powerful yet gentle care.

Model applying COSRX Advanced The Vitamin C 23 Serum under the eye area with a dropper; high-potency 23% stabilized Vitamin C visibly brightens dull skin, fades dark spots, and refines texture. Clinically proven to improve skin smoothness by 92.32% and promote firmer, more even-toned skin after 4 weeks of use. Close-up of mature model applying COSRX Advanced The Vitamin C 23 Serum near the eye contour; antioxidant-rich Vitamin C and E complex visibly smooths fine lines, reduces wrinkles, and evens tone for firmer, brighter skin. Clinically shown to improve elasticity and reduce pore volume by 38.15% after 4 weeks of consistent use. Model applying COSRX Advanced The Vitamin C 23 Serum with a luminous glow; dual-layer formula of stabilized Vitamin C and Hyaluronic Acid deeply hydrates, brightens dull areas, and refines uneven texture for a smooth, radiant finish. Clinically proven to reduce five types of blemishes by 30.14% after 4 weeks of use. Smiling mature model applying COSRX Advanced The Vitamin C 23 Serum to the under-eye area; clinically proven antioxidant-rich formula enhances elasticity, smooths wrinkles, and brightens uneven tone for visibly youthful skin. Triple-complexion redness improved by 30.14% after 4 weeks of consistent use.

KEY INGREDIENTS

Provides radiance and lights up skin tone

Pure Vitamin C 23%
(High-concentration)

Revitalize the skin with powerful antioxidant care

Super Vitamin E (Tocotrienol) & Glutathione

Boost firmness and brighten the complexion

Adenosine & Niacinamide

Your slow-Aging
Routine Guide

Step by step routine for youthful & healthy skin

Start with Low pH Good Morning Gel Cleanser to gently remove impurities while maintaining the skin’s natural balance.

Step 1 - Cleanse

Apply The 6 Peptide Skin Booster Serum to prep the skin and enhance absorption for the next steps.

Step 2 - Tone & Prep

Use Advanced The Vitamin C 23 Serum to target dullness, dark spots, and uneven tone for a radiant complexion.

Step 3 - Brighten

Follow with The Ceramide Skin Barrier Moisturizer to lock in hydration and strengthen the skin barrier.

Step 4 - Moisturize

Finish with Vitamin E Vitalizing Sunscreen SPF 50+ for non sticky protection against UV damage without white cast.

Step 5 - Don’t forget to

GET FULL ROUTINE NOW & SAVE 20%

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FAQ
What makes COSRX Advanced The Vitamin C 23 Serum different from other Korean Vitamin C serums?

COSRX Advanced The Vitamin C 23 Serum is formulated with a powerful antioxidant network featuring 23% pure Vitamin C, Super Vitamin E (Tocotrienol), and Glutathione. Based on research, this blend helps stabilize inherently unstable pure Vitamin C, allowing it to be delivered gently and effectively to the skin, making it more comfortable to use compared to many traditional Vitamin C serums.

How does the Vitamin C 23 Serum help with dark spots and hyperpigmentation?

COSRX Advanced The Vitamin C 23 Serum combines 23% pure Vitamin C with Super Vitamin E and Glutathione for powerful antioxidant care. This high-strength formula stays fresh, absorbs smoothly, and delivers visible brightening and texture improvement without irritation even for sensitive skin.

Can COSRX Vitamin C 23 Serum refine pores and smooth skin texture?

Yes. Clinical testing showed a 38% reduction in pore volume and over 92% improvement in skin texture after consistent use. This pure Vitamin C 23% serum helps resurface dull areas, reduce the appearance pores, and leave skin smoother and more even-looking.

When can I expect to see visible results from the Vitamin C 23 Serum?

Most users notice improved brightness and smoother texture within two weeks, with visibly clearer, firmer, and more even-toned skin after four weeks of consistent use. Clinical trials confirmed measurable improvements in pigmentation, pore appearance, and elasticity during this period.

Is the COSRX Vitamin C 23 Serum suitable for sensitive or acne-prone skin?

Yes. The formula is non-comedogenic and irritation-tested to ensure it works gently on all skin types. The dual-layer structure combines antioxidant power with soothing hydration from Panthenol and Allantoin, helping repair the skin barrier while minimizing redness or stinging.

How does this serum support anti-aging and skin elasticity?

Vitamin C helps support collagen, while Adenosine boosts this effect for enhanced resilience. Clinical data showed, during this test period, about a 15% improvement in skin elasticity and a reduction in the appearance of wrinkle depth, promoting a smoother, more lifted look with continued use.

How should I store and apply the COSRX Vitamin C 23 Serum for best results?

Keep the serum refrigerated between 3–10°C to maintain freshness. Replace the cap with the provided dropper after opening, shake lightly, and apply a few drops to clean, toned skin. Gently pat until absorbed and follow with moisturizer and SPF during the day.

Overall rating: 4.2538652 / 5 from 2005 reviews.

AI Generated Review Summary

COSRX's Advanced The Vitamin C 23 Serum offers a high concentration of pure vitamin C, praised for its brightening effects and smooth texture. While many customers report positive results and a radiant appearance, some have noted irritation and dryness. The product absorbs quickly and is generally well-received for its hydrating and moisturizing properties.

Summary topics

  • Results: 7%
  • Looks: 7%
  • Texture: 6%
  • Feels: 15%
  • Absorbs: 6%

Review topics: [absorbs, results, color, issues, ingredients, irritation, improvement, price, wrinkles, weight, quality, works, fragrance, spots, benefits, use, feels, texture, packaging, lines, design, value, formula, difference, skin, looks, amount, effect, glow, face].

Review highlights

  • "My skin looks brighter and feels great after using this product for just a couple weeks." — Jenilee
  • "great price, works great , have seen immediate results, skin feels and looks smoother" — Hamid Z.
  • "My skin felt super hydrated and bright - the mix of the vitamin C, E and hyaluronic acid was great for my skin!" — Mommysbeautyreviews

Reviews

Even skin tone

"I have noticed a different in my skin since using this product. I have noticed the brightening effects. My skin tone is more even with less dark spots. While I do not store the product in the fridge one it is opened, I store my unopened products in the fridge. I made the mistake of leaving an unopened one in a cabinet. It evaporated within 2 months."

— Chikanele O. (5/5)

Great product, skin glows

"I have used other Serum Vitamin C brands, when I first put this in a little goes a long way. My skin felt refreshed and hydrated. I’ve noticed my dark spots are somewhat lighter. My granddaughters remarked on how my skin glows. Truly a great and worthwhile product that definitely won’t break the bank. l"

— Terri T. (5/5)

Use it every morning in

"Use it every morning in my routine. I pair it with the alpha arbutin serum and it has made great results by evening out my skintone and lessing acne spots and scars. The serum feels great on my skin and not sticky at all. I suggest pairing it with the alpha arbutin serum for maximizing results of evening the skintone."

— Molly P. (5/5)

COSRX Vitamin C23

"I am 65 plus year old woman with sensitive skin. Vitamin C23 makes my skin brighter and looks smoother."

— Valerie M. (5/5)

My holy grail of a

"My holy grail of a vitamin C it’s lite but powerful this is a staple in my skincare routine!!! The packaging is cute as well!!"

— Ja’Daisa J. (5/5)

Highly Recommend

"After using consistently I have started to notice my skin looking brighter and more even, and it gives me a really nice, natural glow without feeling heavy or greasy. Overall, this has been a great addition to my routine, and I definitely recommend it to anyone who has sensitive skin but still wants the benefits of Vitamin C."

— Breana C. (5/5)

Vitamin C

"Love this serum. It's just a little greasy feeling."

— Emily S. (5/5)

Best Vitamin C serum of

"Best Vitamin C serum of all! I’ve tried different brands before but this is by far the best!"

— Ritchell K. (5/5)

Loving this! Repurchased. Helping with

"Loving this! Repurchased. Helping with skin eveness and fading dark spots"

— Keisha M. (5/5)

Works well evens out my

"Works well evens out my skin"

— Marcy M. (5/5)

Q&A