Dose-Dependent Histopathological and Structural Impact of Chemical Hair Straighteners on Scalp Epithelium and Hair Fibers Using Albino Wistar Rats

This study on albino Wistar rats examined the effects of chemical hair straighteners on scalp and hair, revealing that repeated exposure leads to significant hair and scalp damage. The damage includes cortical fading, cuticular lifting, keratin degeneration, pigment loss, epidermal thinning, keratinocyte necrosis, follicular atrophy, and collagen matrix disruption, all worsening with increased exposure. These findings highlight the cytotoxic risks of chemical straighteners and their potential systemic absorption, despite the study's limitations of using an animal model and a single product. The results emphasize the need for further human research and safer hair cosmetic practices.