A chemical ingredient used in some hair relaxing and/or straigtening products that is designed to break the protein bonds that provide human hair with its natural texture. Ammonium Thioglycolate is often called "thio". It is the active chemical ingredient that is also found in chemical waving treatments.
Daily Hair Tip
If you lie on your back while you sleep this could cause hair stress leading to split ends in the back. To avoid hair stress tie hair back using a soft scrunchie band.