Obagi Tretinoin Gel*Call to purchase* The science behind Obagi Tretinoin Obagi Tretinoin uses the healing abilities of Vitamin A and delivers it in an easy to use topical skincare cream. The reason that Obagi Tretinoin is so powerful is because it is formulated in a way that is ready to use meaning that when it gets absorbed into your body, it can instantly and naturally be transformed to usable Vitamin A, the precursor needed that leads to increased skin cell growth to