
Image: cosrx.com
COSRX
Advanced The Vitamin C 23 Serum
A serum built around Vitamin C and Vitamin C, for barrier repair and hydration.
Brand price
USD 25.00 · checked 25 Sept 2026 · on the brand's site
From the brand
What the brand says about this product. Our ingredient analysis follows below.
The brand recommends it for
- Dark spots & pigmentation
- Fine lines & wrinkles
- Dullness
How to use
After cleansing and toning, apply 2–3 drops to the entire face. Pat gently for better absorption. Follow with moisturizer and SPF during the day.
Caution
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.
What's inside
Ingredients List
8 trigger at least one check · 22 trigger none
- Vitamin C
- Vitamin C (L-ascorbic acid)
- Anti-Aging
- Anti-Pollution
- Antioxidant
- Brightening
- Dark Spots
- Even Tone
- Panthenol (provitamin B5)
- Barrier Repair
- Hydrating
- Reduces Irritation
- Vitamin C
- Vitamin C derivative (stable)
- Antioxidant
- Brightening
- Dark Spots
Key Ingredients
Hyaluronic acid1
Hyaluronic acid and its salts; a humectant that binds water to the skin.
Vitamin C2
Vitamin C in any form: an antioxidant and brightener.
Benefits
Hydrating8
Boosts hydration and relieves dry, tight skin.
Acetyl Glucosamine, Butylene Glycol, Dimethicone, Helianthus Annuus Seed Oil, Panthenol, Sodium Hyaluronate, Squalane, Tocopherol
Barrier Repair11
Strengthens and restores the skin's natural barrier.
Allantoin, Camellia Japonica Seed Oil, Carthamus Tinctorius Seed Oil, Dimethicone, Elaeis Guineensis Oil, Glycyrrhiza Glabra Root Extract, Helianthus Annuus Seed Oil, Niacinamide, Panthenol, Squalane, Tocopherol
Reduces Irritation3
Eases discomfort and supports skin resilience.
Redness Reducing3
Soothes visible redness and calms irritation.
Smoothing8
Refines rough or uneven texture.
Allantoin, Camellia Japonica Seed Oil, Dimethicone, Elaeis Guineensis Oil, Glycyrrhiza Glabra Root Extract, Helianthus Annuus Seed Oil, Niacinamide, Squalane
Brightening5
Restores radiance to dull, tired skin.
3-O-Ethyl Ascorbic Acid, Ascorbic Acid, Glutathione, Glycyrrhiza Glabra Root Extract, Niacinamide
Dark Spots5
Fades dark spots for a more even tone.
3-O-Ethyl Ascorbic Acid, Acetyl Glucosamine, Ascorbic Acid, Glycyrrhiza Glabra Root Extract, Niacinamide
Even Tone3
Evens out patchy or uneven colour.
Antioxidant3
Shields skin from free radical damage.
Anti-Pollution4
Helps defend against airborne pollutants.
Concerns
May Worsen Seborrheic Dermatitis5
May feed the yeast involved in seborrheic dermatitis.
Acetyl Glucosamine, Camellia Japonica Seed Oil, Carthamus Tinctorius Seed Oil, Elaeis Guineensis Oil, Helianthus Annuus Seed Oil
May Worsen Oily Skin5
May increase shine or excess oil.
Camellia Japonica Seed Oil, Carthamus Tinctorius Seed Oil, Elaeis Guineensis Oil, Helianthus Annuus Seed Oil, Squalane
Ingredients Explained
Click on any ingredient to learn more about it
Aqua
Solvent
Ascorbic Acid
Antioxidant, Buffering, Fragrance, Skin Conditioning
Ascorbic Acid is L-ascorbic acid.
Learn more about Ascorbic Acid →Butylene Glycol
Fragrance, Humectant, Skin Conditioning, Solvent, Viscosity Controlling
Butane-1,3-diol (CAS No. 107-88-0/ EC No. 203-529-7) (R)-(-)-butane-1,3-diol” (CAS No. 6290-03-5/ EC No. 228-532-0)
Learn more about Butylene Glycol →Dimethicone
Antifoaming, Skin Conditioning, Emollient, Skin Protecting
Dimethicone is a silicone.
Learn more about Dimethicone →Panthenol
Antistatic, Hair Conditioning, Skin Conditioning
Panthenol is panthenol (provitamin B5).
Learn more about Panthenol →3-O-Ethyl Ascorbic Acid
Skin Conditioning
3-O-Ethyl Ascorbic Acid is a vitamin C derivative.
Learn more about 3-O-Ethyl Ascorbic Acid →Squalane
Hair Conditioning, Refatting, Skin Conditioning, Emollient
Squalane is a face oil.
Learn more about Squalane →Sodium Hydroxide
Buffering, Denaturant
Sodium hydroxide
Learn more about Sodium Hydroxide →Caffeine
Fragrance, Perfuming, Skin Conditioning
Caffeine is the heterocyclic organic compound that conforms to the formula
Learn more about Caffeine →Sodium Hyaluronate
Humectant, Skin Conditioning
Sodium Hyaluronate is a hyaluronic acid.
Learn more about Sodium Hyaluronate →
Dupes
- COSRX The Vitamin C 13 Serum84% match
- Isntree Onion Newpair Ampoule Plus65% match
- Arencia Holy Hyssop Serum 3064% match
- Goodal Green Tangerine Vita C Niacinamide 10 Toning Ampoule64% match
- Arencia Vitamin C Booster Shot64% match
- innisfree Green Tea Enzyme Vitamin C Brightening Serum63% match