Effects of Permanent Waving on Changes of Protein and Physicomorphological Properties in Human Head Hair
May 2009
in “
International Journal of Cosmetic Science
”
New to Keratin? There is a guide in the encyclopedia. Read the guide → Studysummary 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. Our plain-language summary of this paper — not a Tressless recommendation.
The 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 treatments generally decreased the protein content in hair, 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 examined physical properties such as tensile strength and diameter, noting that repeated treatments and the use of sodium thioglycolate lotion had more detrimental effects. Scanning electron microscopy revealed that multiple treatments increased hair surface damage, although a single treatment did not show noticeable changes.
