Yes, Lytera and Retin-A can be used together. They are part of a total skin care regimen for mild to moderately sun damaged skin. The Lytera lightens the skin and the Retin-A thickens the dermis, revascularizes the skin, corrects nuclear damage and makes the dead cells stick less. To these should be added an alpha or beta hydroxy cleanser to remove the built up dead cells, an antioxidant and pH balancer such as Vitamin-C to restore the normal skin function and a good zinc oxide UVA sun block. see a physician who specializes in skin rejuvenation.