Methods of treating aging related skin changes and of increasing skin thickness with topical administration of N-acyldipeptide derivatives and retinol are described. Combinations of retinol and N-acyldipeptide derivatives, are therapeutically effective for increasing skin thickness, and for treating extrinsic and intrinsic aging and aging related skin changes, such as fine lines, wrinkles, photoaging, hyperpigmentation, laxity, age spots, lentigines, mottled skin, and cellulite.