Wyoming State Board Cosmetology 2025 – 400 Free Practice Questions to Pass the Exam

The main active ingredient in most hair straightening products is sodium hydroxide. This chemical is known for its strong alkaline properties, which help to break down the protein structure of the hair. When sodium hydroxide is applied, it allows the hair to become more pliable and easier to reshape into a straighter form. Typically found in formulations for relaxers, sodium hydroxide effectively reduces curliness by disrupting the disulfide bonds in the hair, making it a favored choice for achieving straight hairstyles.

In contrast, while hydrogen peroxide is often used in hair bleaching processes or permanent waving, it does not serve the same purpose as the active ingredient for straightening. Sodium chloride is commonly found in cosmetic products but usually acts as a thickening agent or preservative rather than a straightening agent. Calcium carbonate is primarily used in other applications, such as in certain types of hair conditioners or treatments, but it does not function as an active ingredient for hair straightening.