2025 Red Seal Hairstylist Complete Practice Exam

Hair relaxers are primarily formulated using sodium hydroxide or ammonium thioglycolate as their key active ingredients. Sodium hydroxide is a strong alkaline chemical that works to break the disulfide bonds in the hair, allowing it to be straightened. This process effectively changes the texture of the hair, making it smoother and more manageable for individuals with curly or coily hair types.

Ammonium thioglycolate is a milder alternative to sodium hydroxide and is commonly found in some relaxer formulations aimed at reducing the harsh effects traditionally associated with hair straightening. Both sodium hydroxide and ammonium thioglycolate facilitate the chemical alteration of hair structure, making them essential for the relaxing process.

Other options listed, such as hydrogen peroxide or ethanol, do not primarily serve to relax hair; rather, hydrogen peroxide is often used in hair coloring processes. Silicone and natural oils are typically added to hair products for their conditioning properties, but they do not actively relax the hair. Glycerin and herbal extracts, while beneficial for moisture and nourishment, also do not contribute to the hair relaxation process. Thus, the correct answer highlights the most significant active ingredients involved in hair relaxers.