The present invention relates to the use of one or more tripeptides selected from the group consisting of NLys-Pro-ValC, NLys-Pro-ThrC and NpGlu-His-ProC for the reduction of oxidative stress. The above tripeptides are particularly useful for the treatment of a disease or damage caused by oxidative stress; such as vitiligo, scleroderma, necrosis, or erythema; furthermore, a disease or damage of the hair, like premature hair loss or premature formation of grey hair. Furthermore the invention relates the cosmetic use of the above tripeptides, in particular against skin aging. Further the invention relates cosmetic compositions containing at least one of said tripeptides.