13 citations
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September 2017 in “International Journal of Cosmetic Science” This study found that waving virgin human hair with thioglycerol at pH 9.0 using ammonia solution caused less damage than using thioglycolic acid, while maintaining good waving efficiency.
This study found that adding Rosehip extract to permanent waving products with cysteine improved waving efficiency and reduced hair damage compared to thioglycolate-based products.
August 2026 in “Journal of the Korean Society of Cosmetology” In this study, researchers observed that Sedum takesimense extract improved the surface properties, moisture retention, tensile strength, and wave formation of damaged hair compared to a water control, even after additional chemical and UV damage, suggesting its potential as a protective hair treatment.
18 citations
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January 2008 in “Sen'i Gakkaishi” This study observed that repeated perm treatments decrease disulfide bonds in hair due to their conversion largely into cysteic acid, affecting the waving efficiency depending on the reduction agent used.
15 citations
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July 2001 in “Clinics in Dermatology” Current hair removal methods improve appearance but need more research for better options.