How do thio relaxers straighten the hair?

(Q) How do thio relaxers straighten the hair. The hydroxide ion is the active ingredient in all hydroxide relaxers. The process by which hydroxide relaxers permanently straighten hair; They remove a sulfur atom from a bond and turn it into a lanthionine / another bond ...

Basically they break the disulfide bonds in hair, similar to the permanent waving process. When enough of the disulfide bonds in the hair are broken, the relaxer is rinsed from the hair and the hair is towel dried.