Minnesota Cosmetology State Practice Exam 2026 - Free Cosmetology Practice Questions and Study Guide

The primary ingredient in most hair relaxers is sodium hydroxide. Sodium hydroxide is a lye-based chemical that works by breaking down the disulfide bonds in the hair's keratin structure, allowing the hair to be straightened or relaxed. This chemical reaction effectively alters the hair's texture, making it smoother and more manageable. Sodium hydroxide-based relaxers are known for their effectiveness in treating resistant or coarse hair, often producing a long-lasting straightening effect.

While other ingredients such as calcium hydroxide and potassium hydroxide are also used in certain formulations, sodium hydroxide is the most commonly used and recognized for its strength and efficacy. Ammonium thioglycolate, on the other hand, is typically associated with perms rather than relaxers, as it serves a different purpose in altering hair texture. Understanding the role of these chemicals is essential for anyone involved in cosmetology, particularly in making informed decisions about hair care and treatment options.