5 citations
,
June 2013 in “Fashion business” This study found that adding rose hip extract to permanent wave solutions increased wave effectiveness and reduced hair damage, although variations in hair type may affect the results.
18 citations
,
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.
3 citations
,
August 2008 in “PubMed” This study found that digital perm treatments using sodium thioglycolate lotion led to the most significant reduction in protein content and greater hair damage compared to other methods and lotions.
2 citations
,
September 2010 in “Journal of the Korea Academia-Industrial cooperation Society” This study found that increasing collagen concentration to 2% in permanent wave treatments reduced hair damage but impaired curl formation.
May 2009 in “International Journal of Cosmetic Science” In this study, permanent waving treatments, especially those using lotion B and repeated procedures, were found to significantly damage hair protein content and physical properties.