29 citations,
August 2005 in “Biopolymers” L-cysteine slows down the breaking of bonds in hair due to electrostatic interactions.
[object Object] 20 citations,
December 2012 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.
5 citations,
April 2005 in “Journal of applied polymer science” PEI diffuses into hair at a constant rate, and urea speeds up this process.
7 citations,
January 2001 in “Comprehensive series in photosciences” UV radiation significantly damages hair, especially with humidity, making it more vulnerable to further damage.
5 citations,
October 2003 in “PubMed” Chemical treatments and light exposure damage hair proteins.