One of several prescription-only drugs (others include Renova, Retin-A Micro, and Avita) that contain tretinoin (technical name: all-trans retinoic acid), which is the acid form of vitamin A, as the active ingredient. In skin, tretinoin is the form of vitamin A that can actually affect cell production by binding to the tretinoin receptor sites on the cell. There is a great deal of research establishing that tretinoin is effective in improving cell production in skin that has been damaged (often by exposure to sunlight). Tretinoin is a valid method for addressing wrinkles and, overall, for improving cell production. Applying tretinoin does not produce miraculous results, but the positive outcome in terms of skin health is indisputable. However, it is highly possible that applying tretinoin to the skin will cause irritation, which is a major drawback of this drug.