One of the fundamental characteristics of sun-damaged skin is that the outer layer becomes thickened and yellow and the underlying layer, where new skin cells are produced, becomes damaged, generating abnormal cell growth and hypermelanin production. The abnormal cell growth also results in malformed elastin, collagen deterioration, and distorted circulation of the blood and lymph systems. Regular use of sunscreen can slow this damage, allow for some improvement, and prevent further destruction. But topical tretinoin has been shown to partially reverse the clinical and histological (structural) changes induced by the combination of sunlight exposure and chronological aging. A formulation of tretinoin in an emollient cream (as in Renova, Avita, Tazorac, or generic tretinoin) has been extensively investigated in multicenter double-blind trials, and has been shown to produce significant improvement within four to six months of daily use when used as part of a regimen including sun protection and moisturizer.
Alpha-hydroxy acids (AHAs) have also been widely used for therapy of photodamaged skin, and these compounds have been reported to normalize hyperkeratinization (overthickened skin) and to increase viable epidermal thickness and dermal glycosaminoglycans content. In other words, AHAs have a postive effect on the surface and lower layers of skin. To sum this all up, recent work has substantially described how the aging process affects the skin and has demonstrated that many of the unwanted changes can be improved by topical therapy.
Add sunscreen to the mix and a “moisturizer” in a texture for your skin type that is loaded with antioxidants, skin-identical ingredients, and cell-communicating ingredients and you have the best combination possible to fight wrinkles.
(Sources: Cutis, August 2001, pages 135-142; Journal of the European Academy of Dermatology and Venereology, July 2000, pages 280-284; American Journal of Clinical Dermatology, March-April 2000, pages 81-88; Journal of Cell Physiology, October 1999, pages 14-23; Skin Pharmacology and Applied Skin Physiology, May-June 1999, pages 111-119; British Journal of Dermatology, December 1996, pages 867-875.)