A growing body of evidence suggests that cumulative photo-oxidative damage contributes to the photo aging process, and thus antioxidant therapy that modulates photo-oxidative stress is believed to be an important strategy against photo aging. Several antioxidants have already been proven to work in experimental conditions and, in the near future, it is likely that the y will become routine in clinical use. The free radical theory proposes that photo aging, which is different from chronological aging, may result from imperfect protection against cumulative stress of free radicals produced by chronic and repeated ultraviolet irradiation. Since the skin is always in contact with oxygen and is occasionally exposed to ultraviolet light, skin is one of the best target organs of environmental photo-oxidative stress. A growing body of evidence suggests that reactive oxygen species are generated by ultraviolet irradiation resulting in the structural and functional alteration of cutaneous components that should affect the photo aging process over a long period. Thus the possible use of antioxidants that attenuate photo-oxidative toxicity is believed to be an important strategy modulating photo aging. Several antioxidants have readily been proved to work in the experimental conditions. EXCERPTS from: Journal of Dermatological Science 9 (1995) 79-86 Review: Photo aging from an oxidative standpoint By Yoshiki Miyachi Department of Dermatology, Gunma University School of Medicine. Maebashi, Gunma 371, Japan