Tretinoin (Retin-A, Refissa, Renova) is a derivative of Vitamin A and is the treatment of choice for comedonal acne, or whiteheads and blackheads. It works by increasing skin cell turnover promoting the extrusion of the plugged material in the follicle. It also prevents the formation of new comedones. Tretinoin is also the only topical medication that has been proven to improve wrinkles. When used with lightening products, Tretinoin can also help lift stubborn pigment and sun damage. Retinol is the over-the-counter form of Retin-A and Tretinoin. Patients who have extremely sensitive skin may tolerate Retinol better than it's prescription form.