Which acid is described as the primary reducing agent in these services?

• A. Thioglycolate Acid
• B. Acetic Acid
• C. Lactic Acid
• D. Hydrochloric Acid

Answer: (A)

Hair chemical texture services hinge on breaking sulfur-sulfur cross-links in keratin with a reducing agent. The thioglycolate acid provides thiol groups (-SH) that attack disulfide bonds (-S-S-), reducing them to two free thiol groups and allowing the hair to be reshaped. This makes it the primary reducing agent in these formulations. The other acids listed do not perform this bond-breaking role; acetic, lactic, and hydrochloric acids are used mainly to adjust or maintain pH or for conditioning effects, not to reduce disulfide bonds. After shaping, a neutralizer re-forms the bonds by oxidizing the thiol groups, locking in the new texture.