The Vitamin C 13 Serum

Image: cosrx.com

COSRX

The Vitamin C 13 Serum

A serum built around Vitamin C and Vitamin C, for barrier repair and hydration.

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Brand price

USD 21.00 · 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, apply a few drops to the skin during the serum step. Using your fingertips, gently massage the serum into the skin, working from the center of the face outward until fully absorbed. /KEEP REFRIGERATED (3~10°C)/ *For best results, use immediately after purchase. Once opened, store upright in the refrigerator.

Caution

*Cautions* 1. For first use, attach the dropper included in the product package. 2. To preserve the active ingredients, we recommend using within 2 months of opening. 3. Can I use a highly concentrated serum only in the evening? No! This serum can be used both in the morning and evening. 4. If used in the morning, always follow with a sunscreen of SPF 30 or higher. 5. As this product contains a high concentration of Vitamin C, we recommend avoiding use alongside Copper Peptide products, including our Blue Peptide Serum & Cream. 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

3 trigger at least one check · 22 trigger none

clear
WaterSkin Conditioning
—
clear
Ascorbic AcidAntioxidant
—
  • Vitamin C
  • Vitamin C (L-ascorbic acid)
  • Anti-Aging
  • Anti-Pollution
  • Antioxidant
  • Brightening
  • Dark Spots
  • Even Tone
clear
Butylene GlycolHumectant
1 / 0
  • Hydrating
clear
Dipropylene GlycolPerfuming
0-1 / —
clear
TromethamineBuffering
0 / —
clear
3-O-Ethyl Ascorbic AcidSkin Conditioning
—
  • Vitamin C
  • Vitamin C derivative (stable)
  • Antioxidant
  • Brightening
  • Dark Spots
clear
PanthenolSkin Conditioning
0 / 0
  • Panthenol (provitamin B5)
  • Barrier Repair
  • Hydrating
  • Reduces Irritation
flagged
Acetyl GlucosamineSkin Conditioning
—
  • Fatty alcohols (Malassezia)
  • Dark Spots
  • Hydrating
  • May Worsen Seborrheic Dermatitis
clear
CaffeineSkin Conditioning
—
  • Under-Eye Care
clear
Sodium HyaluronateHumectant
0 / 0
  • Hyaluronic acid
  • Hydrating

Key Ingredients

  • Face oil1

    An oil formulated to be used on the face.

    Squalane

  • Vitamin E1

    Tocopherols — fat-soluble antioxidants.

    Tocopherol

  • Vitamin C (L-ascorbic acid)1

    L-ascorbic acid, the unesterified form of vitamin C.

    Ascorbic Acid

  • Vitamin C derivative (stable)1

    Stable derivatives of ascorbic acid.

    3-O-Ethyl Ascorbic Acid

  • Panthenol (provitamin B5)1

    Provitamin B5 — a humectant and soother.

    Panthenol

  • Hyaluronic acid1

    Hyaluronic acid and its salts; a humectant that binds water to the skin.

    Sodium Hyaluronate

  • Niacinamide1

    Vitamin B3 — supports the barrier and evens tone.

    Niacinamide

  • Vitamin C2

    Vitamin C in any form: an antioxidant and brightener.

    3-O-Ethyl Ascorbic Acid, Ascorbic Acid

Benefits

Concerns

Ingredients Explained

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