COSRX Advanced The Vitamin C 23 Serum 20ml, 2 Pack

Features

COSRX Advanced The Vitamin C 23 Serum 20ml, 2 Pack features a high-potency, dual-layered formula formulated with 23% pure Vitamin C. Designed to maximize skin absorption and deliver intensive brightening and anti-aging benefits, this serum revitalizes dull skin tone, restores radiance, and smooths texture. To preserve the potency of pure Vitamin C and delay oxidation, the product utilizes a specialized container engineered to block light, heat, oxygen, and external air while regulating internal gas. It comes with individually packaged droppers for hygienic application and is formulated without added fragrances.

Benefits

This concentrated serum provides comprehensive early-aging care and targeted tone management. It targets blemishes, dark spots, hyperpigmentation, dullness, loss of elasticity, and fine lines. By delivering robust antioxidant protection, it neutralizes free radicals to support skin vitality across multiple skin layers. Additionally, it improves skin clarity and smoothness while reducing the appearance of pores for a clear, firm, and radiant complexion.

Main Ingredients and their effects

Pure Vitamin C (Ascorbic Acid 23%): Provides concentrated antioxidant and anti-aging benefits, helping to correct uneven skin tone, brighten hyperpigmentation, and enhance overall skin radiance.

Super Vitamin E (Tocotrienols) & Tocopherol: Works synergistically with Vitamin C to deliver enhanced antioxidant power, protecting the skin from oxidative stress.

Glutathione: Complements Vitamin C and Vitamin E to form an antioxidant network that boosts skin clarity and brightens dull complexions.

Niacinamide & Adenosine: Niacinamide further enhances skin brightening and tone improvement, while Adenosine targets wrinkles and boosts skin elasticity.

Panthenol, Hyaluronic Acid, & Allantoin: Provide rich moisture and soothing care, ensuring the high-concentration formula remains gentle and hydrating on the skin.

Clinical test results

In clinical testing on 20 adult subjects (conducted May 3, 2025 – June 30, 2025 by Dermacosmetic Skin Science Research Institute):

Skin texture improved by 92.32%.

Skin radiance boosted by 34.81%.

Visible skin elasticity improved by 15.07%, while internal skin elasticity increased by 11.81%.

Skin clarity improved by 15.06% and internal melanin reduced by 14.15%.

Blemish traces improved by 8.87%, with overall blemish area decreasing by 17.43%, hidden blemishes reduced by 14.15%, and blemish count reduced by 11.02%.

Pore care measurements after 4 weeks of use demonstrated a 38.15% reduction in pore volume, 36.05% reduction in pore area, 28.45% reduction in pore count, and 13.01% reduction in pore depth.

Additional clinical evaluation on 23 adult women (conducted May 14, 2025 – June 12, 2025 by P&K Skin Clinical Research Center) demonstrated a 3-step antioxidant effect: a 38.9% improvement in skin stratum corneum oxidation, a 42.6% improvement in skin lipid oxidation, and a 46.8% improvement in skin protein oxidation.

The product has successfully passed primary skin irritation testing, sensitive skin irritation testing, and non-comedogenic testing suitable for acne-prone skin.

Usage instructions

Due to the nature of high-concentration pure Vitamin C, do not shake the bottle heavily before opening to prevent overflow. After securing the dropper, gently shake side to side before use. Apply an appropriate amount evenly over the face. If using alongside products containing Copper Peptides, separate their application by using them at different times of the day (morning versus evening).

Storage instructions: Store upright in a refrigerator between 3°C and 10°C both before and after opening. Keep away from high temperatures and direct sunlight. It is recommended to use the product within 2 months of opening to ensure freshness.