D_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.
Avoid mixing with retinol or acids in the same routine.
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
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

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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.