New Jersey Cosmetology and Hairstyling Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

The primary ingredient in most hair relaxers, particularly in those designed for more permanent and effective results, is sodium hydroxide or calcium hydroxide. These chemicals function as strong alkalis, which help to break the bonds in the hair's protein structure that are responsible for its natural curliness or wave pattern. By altering the disulfide bonds in the hair, these hydroxides allow the hair to be straightened effectively.

Sodium hydroxide is particularly common in lye relaxers, while calcium hydroxide is often used in no-lye relaxers, which some individuals prefer due to lower irritation potential on the scalp. This distinction in chemical formulation caters to different hair types and preferences, making them the mainstay ingredients in the relaxer product formulations available in the market.

In contrast, other options provided do play roles in hair care products but are not the primary ingredients in hair relaxers. Ammonium thioglycolate is typically found in permanent wave solutions and is less effective for permanent hair straightening. Glycerin is a humectant used mainly for its moisturizing properties rather than for structural change in hair. Hydrogen peroxide is commonly associated with hair lightening but does not serve the purpose of relaxing curls. Hence, sodium hydroxide and