Obagi uses retinol to help minimize the appearance of fine lines and wrinkles, smoothing skin texture with minimal irritation. There is good evidence for the use of topical retinol to reduce the appearance of fine lines and wrinkles and prevent premature ageing. In a clinical study, patients reported a noticeable difference in 1 to 3 weeks of using Obagi retinol. This product should be used in the evening after skin cleanse, before going to sleep.