Effects of Perming, Combing, and Stretching on Hair Keratins
January 2001
TLDR Perming, combing, and stretching damage hair by reducing keratin levels.
The study investigated the effects of perming, combing, and stretching on hair keratins, which was relevant for forensic hair identification. It found that these treatments caused hair damage, as evidenced by a significant reduction in keratins within the molecular weight range of 67,000 to 43,000 daltons. The extent of keratin loss correlated with the degree of hair damage.
