The way in which Retinol is delivered to skin can make all the difference in your results. Our NEW Advanced Retinol Nightly Multi-Correct Serum contains Optimized Surface Release Retinol which allows for consistent distribution of potent Retinol. This is unlike common Encapsulated Retinol which like an egg when broken, releases quickly, and when exposed to air & light, starts to degrade and lose potency.