January 1996 in “대한피부과학회지” This study found that permanent dye application causes initial swelling and subsequent degradation of the hair cuticle, with recovery taking more than 8 weeks to approach pre-treatment conditions.
42 citations
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September 2000 in “British Journal of Dermatology” This report describes two children with congenital hypotrichosis and found their short hair is due to a shortened anagen phase, with the condition resolving spontaneously during puberty.
September 2025 in “Sahel Journal of Life Sciences FUDMA” This study reported that albino Wistar rats exposed to chemical hair straighteners showed significant hair fiber damage and scalp skin deterioration, which worsened with repeated and prolonged application, highlighting the cytotoxic potential of these products and potential systemic risks.
8 citations
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November 2019 in “International Journal of Morphology” This study found that using henna dye positively affected hair cuticula pattern and diameters compared to undyed hair, though the degree of change may vary based on hair phenotype and condition prior to treatment.
September 1998 in “JEADV. Journal of the European Academy of Dermatology and Venereology/Journal of the European Academy of Dermatology and Venereology” The document concludes that individualized treatments for hair issues are effective, certain hair changes can indicate neurocutaneous diseases, specific lotions improve skin health, laser hair removal works but needs more study on long-term effects, men's cosmetics are diverse, peeling is effective but can have side effects, and facial pigmentation is often due to overactive skin cells.