Virginia Cosmetology Practice Exam

The primary ingredient in hair relaxers is sodium hydroxide. This compound is highly alkaline and effectively breaks the disulfide bonds in the hair's keratin structure, which is crucial for the relaxing process. Sodium hydroxide works by penetrating the hair shaft, thereby allowing the hair to become more malleable and straight when styled.

Sodium hydroxide is known for its strong, fast-acting properties, making it one of the most common ingredients for chemical hair straightening treatments. It creates a permanent alteration in the hair structure, allowing for more manageable hair styles for individuals with curly or wavy textures.

While other options like ammonium thioglycolate and potassium thioglycolate are also used in various chemical hair treatments, they are typically associated with perming products rather than relaxers. Calcium hydroxide is a less common ingredient used in combination with others in certain types of relaxers, but it is sodium hydroxide that is chiefly recognized for its efficacy and as the primary agent in most hair relaxers.