Which ingredient is commonly used in hair relaxers?

Sodium hydroxide is commonly used in hair relaxers due to its strong alkaline properties, which help break the disulfide bonds in the hair's keratin structure. This process effectively loosens the curls or waves in the hair, allowing for a straightened appearance. The use of sodium hydroxide in hair relaxers is a well-established practice in the cosmetology industry, providing long-lasting results for clients who desire straight hair. Additionally, due to its strength, it is essential for professionals to apply this ingredient carefully and follow proper processing times to avoid damage to the hair and scalp.

The other ingredients listed, such as calcium carbonate and ammonium sulfate, do not possess the same capabilities for chemical straightening of hair. Ketoconazole is an antifungal medication and not related to hair relaxing treatments. Therefore, sodium hydroxide stands out as the main ingredient utilized in the formulation of hair relaxers.