Which chemical is listed as the most common reducing agent in hair texture services?

• A. Thioglycolate Acid
• B. Citric Acid
• C. Ammonia
• D. Sodium Chloride

Answer: (A)

Breaking and reforming the bonds in the hair’s keratin is what makes a texture service possible. The reducing agent donates electrons to the disulfide bonds, converting them into sulfhydryl groups so the hair can be reshaped around the rods. The most common reducing agent used is thioglycolate (thioglycolic acid), often provided as ammonium thioglycolate in commercial formulas, because it effectively breaks those bonds under controlled conditions and can later be neutralized to rebuild them in the new shape. Citric acid, ammonia, and sodium chloride don’t reduce disulfide bonds: citric acid is mainly for pH control or chelation, ammonia raises pH without reducing bonds, and sodium chloride is just salt with no bond-breaking effect.