How to pick✔️ IU shows the retinol amount, so a bigger number means more. New to retinol? Start with 500 IU; 2500 IU comes in a small 15ml bottle. For the eye area, the retinol eye cream (25ml) is ₩3,000 with 29K orders. Retinol is usually a night step, so wear sunscreen by day. You can start every other night.
