What effect does sodium hydroxide have when used in hair relaxers?

Sodium hydroxide is a key ingredient in many hair relaxers, utilized primarily for its strong alkaline properties. When applied to the hair, it breaks down the protein structure, specifically the disulfide bonds in the hair's keratin. This process allows the hair to become more pliable and ultimately results in straightening the curls or waves, transforming a tighter curl pattern into a smoother, straighter appearance.

While sodium hydroxide does have some effects on the overall texture and condition of the hair, its primary function in this context is to enable the hair to be straightened effectively. The other options discuss effects that sodium hydroxide does not primarily provide; it does not add shine, moisture, or color to the hair. Thus, its establishment as a straightening agent is critical in understanding its role in hair relaxation treatments.