IFSCC Magazine, 11 (2008) (4) 317–320Winner of the Poster Award at the IFSCC Congress 2008, Barcelona, Spain.A new method was developed to study aging effects on human hair keratin caused by shampooing, blow drying and sunlight. An automatic multiple process allowed reproducible simulation of the stress of approximately 100 Central European summer days in only 5 working days. Stress‐strain measurements showed a significant weakening of the hair structure due to simulated aging effects. A new keratin active containing peptides identical to those in human hair was developed. The new keratin active penetrates deeply into the cortex cells, which was demonstrated by means of fluorescence microscopy. Aging damage was successfully prevented by strengthening the hair structure.Keywords: Hair keratin, hair strengthening, intermediate filament, keratin aging simulation, restructuring