Thio relaxers use the same ATG as permanent waving but at a:

Thio relaxers utilize the same active ingredient, ammonium thioglycolate (ATG), found in permanent waving products, but they are formulated differently to achieve distinct outcomes. In the context of hair relaxers, a higher concentration of ATG is necessary, combined with a higher pH, to effectively break down the disulfide bonds in the hair's cortex. This higher concentration allows for greater effectiveness in altering the hair’s texture, enabling it to become straighter.

The increased pH level is crucial as it enhances the penetration of the relaxer into the hair shaft and accelerates the chemical reaction needed for the relaxing process. Higher pH levels also help in modifying the hair structure more significantly than lower pH alternatives. Therefore, the formulation of thio relaxers emphasizes these characteristics to provide a strong and lasting straightening effect, distinguishing them from products intended solely for waving.