Utah Cosmetology and Barbering Practice Exam 2025 - Free Cosmetology and Barbering Practice Questions and Study Guide

The main ingredient in most permanent wave solutions used in hair treatments is ammonium thioglycolate. This chemical is a key active component that works to break the disulfide bonds in the hair's keratin structure. When these bonds are broken, the hair can be reshaped into a new curl or wave pattern. Ammonium thioglycolate is favored in many formulations because it allows for a variety of textures and holds, making it versatile for different hair types and styling needs.

Hydrogen peroxide, while sometimes used in conjunction with perm solutions as an oxidizing agent to set the curl, is not the primary ingredient for the actual waving process. Sodium hydroxide is used in some types of hair treatments, particularly in relaxers for straightening hair rather than in permanent waves. Glycerin serves as a moisturizer and may be included in hair products, but it does not play a role in the actual curling process. Thus, ammonium thioglycolate is correctly identified as the main ingredient in permanent wave solutions.