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COSRX The Vitamin C 23 Serum ingredients: is it worth it?
This is a potent, high-impact vitamin C serum with serious brightening potential but equally serious irritation and stability risks.
This is a potent, high-impact vitamin C serum with serious brightening potential but equally serious irritation and stability risks.
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A true 23% ascorbic acid in a water-based system gives strong evidence-backed brightening and antioxidant effects if the pH is kept low enough, but the presence of denatured alcohol and multiple silicones, plus the need for very acidic pH for this concentration, means this will be too aggressive for many skin types and highly dependent on storage and tolerance rather than being a universally safe, elegant formula.
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DemythSkin rates COSRX The Vitamin C 23 Serum 4.5/5 for efficacy and 4.0/5 for safety.
ACTIVE INGREDIENTS BY TIER
Gold Standards
High clinical proof | Skin-transformativeReliable
Proven resultsPotent
Developing evidenceOverhyped | Marketing
Hype | Limited dataDocumented Irritants
Evidence-backed flagFORMULATION BASE (10)⌄
FULL INGREDIENT LIST⌄
Water, Ascorbic Acid (23%), Propanediol, Dimethicone, Tromethamine, Panthenol, Ethyl Ascorbyl Ether, Squalane, Caffeine, Sodium Chloride, Sodium Hyaluronate, Sodium Sulfite, Disodium EDTA, Glutathione, Adenosine, Acetyl Glucosamine, Gardenia Florida Fruit Extract, Allantoin, Dextrin, Tocotrienols, Tocopherololol, Elaeis Guineensis (Palm) Oil, Butylene Glycol, Arginine, Niacinamide, Pentylene Glycol, Alcohol Denat., Helianthus Annuus (Sunflower) Seed Oil, Glycyrrhiza Glabra (Licorice) Root Extract, Methyl Trimethicone, Carthamus Tinctorius (Safflower) Seed Oil, Camellia Japonica Seed Oil, Daucus Carota Sativa (Carrot) Root Extract, Beta-Carotene From the brand Previous page COSRX Sommer-Highlights COSRX Sommer-Essentials Next page Product Description Previous page Next page 1 Results 2 Benefits 3
WHAT EACH INGREDIENT DOES (24)⌄
- Water
- solvent base
- Ascorbic Acid
- primary vitamin C active
- Propanediol
- solvent and penetration enhancer
- Dimethicone
- silicone emollient and texture enhancer
- Tromethamine
- pH adjuster and buffering agent
- Panthenol
- humectant and soothing agent
- Ethyl Ascorbyl Ether
- stable vitamin C derivative
- Squalane
- lightweight emollient and barrier support
- Caffeine
- antioxidant and circulation-support ingredient
- Sodium Chloride
- viscosity and stability adjuster
- Sodium Hyaluronate
- humectant for hydration
- Sodium Sulfite
- antioxidant preservative for stability
- Disodium EDTA
- chelating agent improving stability
- Glutathione
- antioxidant marketing addition
- Adenosine
- skin-conditioning and anti-wrinkle agent
- Acetyl Glucosamine
- skin-conditioning and hydration support
- Gardenia Florida Fruit Extract
- botanical antioxidant and colorant
- Allantoin
- soothing and skin-protective agent
- Dextrin
- stabilizer and texture modifier
- Tocotrienols
- vitamin E family antioxidant
- Tocopherololol
- vitamin E-like antioxidant
- Elaeis Guineensis (Palm) Oil
- emollient oil base
- Butylene Glycol
- humectant and solvent
- Arginine
- amino acid pH adjuster and conditioning
EXTERNAL CITATIONS
Ascorbic Acid: Multiple clinical studies show that 10–20% L-ascorbic acid at low pH improves hyperpigmentation and provides photoprotective antioxidant effects when used daily in leave-on formulations.
Niacinamide: Randomized controlled trials demonstrate that topical niacinamide around 4–5% can reduce hyperpigmentation and improve barrier function and fine lines over 8–12 weeks.
Panthenol: Experimental data indicate that panthenol enhances stratum corneum hydration and supports barrier recovery in irritated skin.
Sodium Hyaluronate: In vivo studies confirm that sodium hyaluronate acts as an effective humectant, increasing skin hydration and elasticity when used topically.
Glycyrrhiza Glabra (Licorice) Root Extract: In vitro and limited clinical data suggest that glabridin and other constituents in licorice extract can inhibit melanogenesis, supporting a modest brightening effect.
DISCLAIMER: THIS ANALYSIS IS FOR INFORMATION ONLY. NOT MEDICAL ADVICE. AI-GENERATED DATA BASED ON PUBLICLY AVAILABLE INGREDIENT LISTS. VERIFY WITH A MEDICAL PROFESSIONAL.
A cheaper serum with a similar formula
A partial ingredient match (31%), not a close dupe.
COSRX The Vitamin C 23 Serum: common questions
Is COSRX The Vitamin C 23 Serum worth it?
COSRX The Vitamin C 23 Serum scores 4.5 out of 5.0 for efficacy (Gold Standard) and 4.0 out of 5.0 for safety (Gentle) on DemythSkin's independent ingredient analysis. This is a potent, high-impact vitamin C serum with serious brightening potential but equally serious irritation and stability risks.
What are the key active ingredients in COSRX The Vitamin C 23 Serum?
COSRX The Vitamin C 23 Serum contains these gold-standard actives with strong clinical evidence: Ascorbic Acid.
Does COSRX The Vitamin C 23 Serum contain fragrance or known irritants?
DemythSkin flags these ingredients in COSRX The Vitamin C 23 Serum as documented irritants: Alcohol Denat..
How is COSRX The Vitamin C 23 Serum scored?
DemythSkin grades every product on two independent scores: efficacy (whether the ingredients have clinical evidence of working) and safety (irritation and sensitisation risk). Ingredients are graded S through D against a database of over 3,000 compounds. Brand and price are not part of the score, and no brand pays for one.
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