Different treatments change the strength and flexibility of human hair.
February 2019 in “PubMed” The research found that twisting hair fibers can show changes in stiffness and damage, and help tell apart different hair treatments.
3 citations
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September 2020 in “Journal of cosmetic dermatology” Coconut oil makes hair stronger and more flexible than mineral oil.
6 citations
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December 1966 in “Textile Research Journal” Animal hair fibers like wool and mohair are strong when dry, but vicuna fibers are very brittle.
29 citations
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December 2011 in “British Journal of Dermatology” A new hair treatment with caffeine and other ingredients makes hair thicker and less likely to break.