Milady Cosmetology Practice Exam 2026 – All-in-One Guide to Master Your Cosmetology Certification!

The correct choice is the metal hydroxide relaxers, as these products are formulated as a single component, meaning they do not require any additional mixing before application. Metal hydroxide relaxers, such as lithium hydroxide and potassium hydroxide, are designed to alter the hair's structure to make it straighter. These relaxers penetrate the hair shaft and permanently reduce curl or wave patterns, providing effective results in straightening.

In contrast, the other types of relaxers typically involve a two-part system. Sodium hydroxide relaxers, for example, require a base and an activator to perform their function, and thio relaxers utilize a chemical reaction that is dependent on mixing the ingredients before use. Acidic relaxers work similarly, involving a combination of components to achieve the desired hair texture change. Thus, metal hydroxide relaxers stand out for their user-friendly, ready-to-apply format.