COSRX The Vitamin C 23 Serum revitalizes skin with a powerful blend featuring 23% pure Vitamin C to brighten and even out skin tone. The formula is infused with an antioxidant-rich Vitamin E derivative to enhance the effects of Vitamin C, along with sodium hyaluronate to help maintain skin’s moisture balance. It also contains allantoin to soothe skin irritation, making it suitable for daily use