Wyoming State Board Cosmetology Practice Exam 2025 - Free Cosmetology Exam Questions and Study Guide

Ammonium thioglycolate is the correct answer because it is the active ingredient used in the perming process. This compound functions as a reducing agent that breaks down the disulfide bonds in the hair's protein structure. By doing so, it allows the hair to be reshaped into curls or waves. Once the hair is curled and the desired shape is achieved, a neutralizing solution is then applied to reform these bonds in their new configuration, thus securing the perm.

In contrast, while hydrogen peroxide is used in some hair processes, such as in lightening hair, it is not the primary agent for creating curls or waves. Hair gel is a styling product that mainly provides hold and texture but does not initiate any permanent chemical changes. Similarly, conditioners are designed to moisturize and improve hair health without altering its structure. Therefore, ammonium thioglycolate specifically is the only product among the options that directly causes the chemical reaction necessary for perming hair.