TLDR Repeated digital perming with sodium thioglycolate lotion significantly damages hair protein and structure.
This study investigated the effects of two types of permanent waving (digital perm and croquignole winding perm) and two waving lotions (cysteamine-HCl and sodium thioglycolate) on human hair. It was found that permanent waving generally decreased protein content, with the most significant reduction (58%) occurring in hair treated three times with digital perm using sodium thioglycolate lotion. The study identified keratin polypeptides and noted that repeated treatments and the use of sodium thioglycolate lotion had more detrimental effects on hair's physical properties, such as tensile strength and diameter, compared to other treatments. Scanning electron microscopy revealed that multiple treatments increased hair surface damage, although a single treatment did not show surface changes.
45 citations
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December 2006 in “Biopolymers” Permanent waving weakens hair by altering its protein structure.
122 citations
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January 2006 in “Molecular & Cellular Proteomics” Human hair contains many proteins, with some being highly abundant and modified.
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February 2005 in “Biopolymers” Chemical hair straightening changes hair proteins and mostly fixes broken bonds.
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February 2002 in “International Journal of Dermatology” Permanent hair dye damages hair but it mostly recovers after 8 weeks; using certain hair care products can help repair it.
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January 1987 in “Electrophoresis” Keratin proteins are consistent across different hair types from the same person.
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January 1987 in “Electrophoresis” Human head hair proteins can be typed into eight distinct patterns, useful for genetic and forensic investigations.
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January 2018 in “Journal of cosmetic dermatology” Conditioners in hair dye reduce damage and improve combability.
Mineral-rich spring water may promote hair growth better than Minoxidil in mice.
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August 2016 in “Journal of microencapsulation” The hair lotion with methyl myristate in niosomes treats grey hair faster and better than the free form.
May 2009 in “International Journal of Cosmetic Science” Permanent waving damages hair protein and weakens hair, especially with repeated treatments using sodium thioglycolate.
