What is the main ingredient in a chemical relaxer?

• A. Ammonium Thioglycolate
• B. Potassium Hydroxide
• C. Sodium Hydroxide
• D. Guanidine Hydroxide

Answer: (C)

Chemical relaxers straighten hair by using a strong alkali to raise the pH and break the hair’s disulfide bonds so they can be reshaped. The main ingredient in a traditional chemical relaxer is sodium hydroxide, a very strong base that drives that high pH and bond-breaking process. Other options listed—such as ammonium thioglycolate, which is a reducing agent used in thioglycolate-based relaxers, or other bases like potassium hydroxide or guanidine hydroxide—are either different types of relaxer formulations or not the primary ingredient in the standard chemical relaxer. The key idea is that the base in the relaxer is what enables the chemical action to relax the hair, with sodium hydroxide being the most common main ingredient.