45 citations
,
December 2006 in “Biopolymers” Permanent waving weakens hair by altering its protein structure.
4 citations
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January 2016 in “Skin research and technology” Oxidative hair dye changes hair color and structure but doesn't weaken it.
June 2017 in “University of the Arts London Research Online (University of the Arts London)” Polymers help reduce damage and improve bleached hair when used during or after bleaching.
20 citations
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December 2012 in “Journal of molecular structure” The study found that thioglycolic acid breaks down hair bonds more consistently than l-cysteine, which is less damaging to hair.
October 2023 in “Animal production science” Vitamin A deficiency changes cattle hair structure, while pregnancy may improve it, suggesting hair can indicate cattle health.