Cosmetics and Quasi-drugs will play new important roles in the aging and stressful society. We have proposed 3 clinical approaches, i.e., anti drying, anti-UV radiation and antioxidation to prevent the skin disorders and aging. Especially, the importance of anti-oxidation is discussed in this paper. The results of the investigation of the peroxidation on the skin surface using a CL-HPLC system, it was considered that singlet oxygen was the key active oxygen species on a human skin. We have clarified the reaction rate constants of the skin surface lipids and thiotaurine with singlet oxygen. Thiotaurine is known as a compound in a metabolism of sulfur containing amino acids in a mammal. We propose that the reconstruction and the reinforcement of the anti-oxidation mechanism in the living system will be useful new clinical approaches in the skin.
