Cosrx The Retinol 0.5 Oil 20mlHighly concentrated 0. 5% pure retinol A youth boosting highly concentrated retinol oil. It features 0. 5% pure retinol to help reduce wrinkles and firm the skin, squalene to calm and promote skin barrier health and vitamin E which is great for anti aging. Great for all skin types. Beginner friendly. How To Use: Start small and slow! During evening care, apply 1 to 2 drops to hand and tap with fingertips from inside out, let absorb. Limit initial use