COSRX The Niacinamide 15 Serum

What is this product?

A short, minimal serum built around 15% niacinamide placed third in the list, supported by zinc PCA and acetyl glucosamine, with no fragrance, essential oils or drying alcohols, making it a strong pick for oily or combination skin wanting a high-strength niacinamide step.

What makes it different?

The formula lists only 15 ingredients total, and niacinamide is printed at 15% and sits third after water and pentylene glycol. Zinc PCA and acetyl glucosamine back it up for oil and texture concerns, while humectants like trehalose and pullulan add a light hydrating feel. The list contains no fragrance, essential oils, ferments or drying alcohols, which keeps the potential irritation load low for a high-percentage actives serum.

What is in it?

The full ingredient list as the brand publishes it, in the printed order. Each name links to what we know about that ingredient.

This brand publishes its ingredient list in Korean only. Names below are the matching INCI names from the Korean Cosmetic Association ingredient dictionary.

Key ingredient

• Water
• Pentylene Glycol
• Niacinamide
• Butylene Glycol
• Acetyl Glucosamine
• 1,2-Hexanediol
• Zinc PCA
• Trehalose
• Xanthan Gum
• Pullulan
• Allantoin
• Ethylhexylglycerin
• Sodium Phytate
• Citric Acid
• Tocopherol

Ingredients with no mark are ones we found nothing notable about, and when marks overlap on one ingredient we show the caution first.