COSRX Advanced The Vitamin C 23 Serum — Efficacy 4.6/5.0, Safety 4.2/5.0 | DemythSkin
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[ DemythSkin Verdict ]
COSRX Advanced The Vitamin C 23 Serum

COSRX Advanced The Vitamin C 23 Serum

SerumBrightening
Efficacy
Exceptional
4.6 / 5.0
Safety
Mostly Safe
4.2 / 5.0
System Verdict
This is a clinically serious brightening/antioxidant serum with an aggressive but well-supported vitamin C system that will work beautifully on resilient skin and absolutely terrorize an unprepared barrier. Efficacy is high because you get both pure ascorbic acid and S Tier 3‑O‑ethyl ascorbic acid, reinforced by niacinamide, licorice, glutathione, tocotrienol and multiple antioxidants, but the very high acid load and potential low pH mean that users with sensitive or compromised skin will trade results for stinging, dryness and barrier stress unless they buffer with a robust moisturizer and introduce it slowly.
Active Ingredients Detected
S Tier: Gold StandardsHigh Clinical Proof | Skin-Transformative
Ascorbic Acid
A Tier: Good BasicsProven Results
3-O-Ethyl Ascorbic AcidAcetyl GlucosamineAdenosineAllantoinAqua / WaterArginineCarthamus Tinctorius (Safflower) Seed OilDimethiconeHelianthus Annuus (Sunflower) Seed OilHydrogenated LecithinNiacinamidePanthenolSqualaneSodium HyaluronateTocopherol
B Tier: Supporting IngredientsPromising Ingredients
Beta-CaroteneButylene GlycolCaffeineDisodium EDTAElaeis Guineensis (Palm) OilMethyl Glucose SesquistearateMethyl TrimethiconePolyglyceryl-3 Methylglucose DistearatePotassium Cetyl PhosphatePropanediolSodium ChlorideSodium SulfiteTocotrienolCarbomerCentella Asiatica ExtractTromethamine
C Tier: Marketing IdolsHype | Limited or Weak Data
Glycyrrhiza Glabra (Licorice) Root ExtractDaucus Carota Sativa (Carrot) Root ExtractGlutathione
D Tier: Potential IrritantsBe Cautious
Ethylhexylglycerin
Analyze on DemythSkin

DemythSkin is an independent ingredient analyzer. Scores are computed by a deterministic rubric from published clinical evidence — no brand pays for a score.