Which ingredient is commonly found in acid-based relaxers?

Acid-based relaxers typically contain glyceryl monothioglycolate, which is a key ingredient known for its gentler formulation. This compound is effective in breaking down the hair's disulfide bonds, allowing for smoothing and straightening the hair while minimizing damage. Glyceryl monothioglycolate's acid pH helps to prevent excessive swelling of the hair, making it suitable for clients with fine or sensitive hair types, as it is less aggressive than some of the other options.

In contrast, the other ingredients mentioned are more characteristic of alkaline relaxers. Sodium hydroxide, ammonium thioglycolate, and potassium hydroxide are all high-pH ingredients that can cause more significant swelling and potential damage to the hair structure. This makes them more suitable for coarse and resistant hair types rather than for clients who may require a milder approach offered by acid-based formulations. Therefore, glyceryl monothioglycolate stands out as the primary ingredient in acid-based relaxers, highlighting its specific role in hair treatment.