What is the main ingredient typically found in hair relaxers?

Hair relaxers are primarily used to chemically straighten curly or wavy hair, making it more manageable. The main ingredient in most hair relaxers is sodium hydroxide, often referred to as lye. Sodium hydroxide works by breaking down the disulfide bonds in the hair's protein structure, which allows the hair to be reshaped and straightened effectively.

This ingredient is strong and alkaline, which is why it is crucial to use it with caution and to follow instructions carefully to avoid scalp irritation or damage to the hair. The high pH level of sodium hydroxide helps to open the hair cuticle and alter the structure of the hair strands, contributing to the relaxing process.

The other choices represent different substances that do not serve the same function. Calcium carbonate is typically used as a buffering agent or filler in other products but does not relax hair. Amino acids are building blocks of proteins and are used in hair treatments to strengthen and condition hair, not to relax it. Keratin is a protein found in hair, skin, and nails and is often used in smoothing treatments but not as a primary ingredient in relaxers. Therefore, sodium hydroxide is specifically chosen for its ability to effectively transform the texture of hair in the hair relaxing process.