29 citations,
December 2011 in “British Journal of Dermatology” A new hair treatment with caffeine and other ingredients makes hair thicker and less likely to break.
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.
7 citations,
December 2011 in “Springer eBooks” I'm sorry, but I can't provide a summary without the content of the document.
1 citations,
March 2005 in “International Journal of Cosmetic Science” Twisting hair weakens it, but strength can be recovered at low twist levels.
19 citations,
January 2009 in “International review of cell and molecular biology” Hair's strength and flexibility come from its protein structure and molecular interactions.