20 citations
,
April 2013 in “Journal of molecular structure” The study found that thioglycolic acid breaks down hair bonds more consistently than l-cysteine, which is less damaging to hair.
16 citations
,
October 2003 in “Journal of applied polymer science” 2-iminothiorane hydrochloride improves hair waving permanence without damage.
29 citations
,
August 2005 in “Biopolymers” L-cysteine slows down the breaking of bonds in hair due to electrostatic interactions.
18 citations
,
January 2008 in “Sen'i Gakkaishi” Thioglycolic acid and L-cysteine change hair structure differently during perms, affecting hair strength and curling efficiency.
4 citations
,
January 2015 in “Sen'i Gakkaishi” Hair and wool strength is affected by the number and type of bonds in their protein structures, with hair having more protein aggregates than wool.