May 2026 in “International Journal of Cosmetic Science” This study found that UV radiation exposure during a simulated Brazilian summer caused more significant mechanical damage to natural hair than bleaching, although both caused comparable structural alterations, with double bleaching leading to the most severe protein degradation.
January 2014 in “한국미용학회지” This study observed that long-term UV-A exposure and semi-permanent dye treatment can cause significant structural damage to human hair, particularly affecting the cuticle and cortex layers.
24 citations
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October 2008 in “PubMed” This article discusses how UV radiation affects hair protein and pigment, destructuralizes keratin, and emphasizes the protective role of melanin, but reports no new clinical results.
1 citations
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February 2003 This study found that UVB radiation primarily causes hair protein loss, while UVA radiation mainly contributes to hair color changes, with no significant differences in mechanical properties observed between photooxidized and non-irradiated hair.
13 citations
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September 2014 in “Journal of photochemistry and photobiology. B, Biology” This study found that UV radiation exposure increased protein elution and altered protein characteristics in hair fibers, suggesting environmental factors impact hair shaft proteins.