The application of a sodium hydroxide relaxer causes the hair to do which of the following?

• A. Soften and swell
• B. Hardens and shrink
• C. Darken
• D. Dry out

Answer: (A)

Sodium hydroxide relaxers work by using a strong base to break the disulfide bonds in hair. This disruption makes the hair’s internal structure more pliable and the cuticle layer can lift, allowing the cortex to expand. As a result, the hair becomes softer and can swell slightly during processing, which is the expected effect when applying a relaxer. It doesn’t harden and shrink, and it doesn’t darken; color change isn’t a typical outcome of relaxing. Dryness is possible with overprocessing or inadequate conditioning, but the primary, correct effect during proper use is softening and swelling.