What are the two main types of chemical hair relaxers used in cosmetology?

The two main types of chemical hair relaxers used in cosmetology are sodium hydroxide and ammonium thioglycolate. Both of these relaxers serve the primary purpose of altering the structure of curly or wavy hair to create a straighter appearance.

Sodium hydroxide, also known as lye, is a strong alkaline relaxer that works by breaking the bonds in the hair's cortex, allowing it to be reshaped. This method is effective for coarse and resistant hair types, providing a permanent straightening effect.

Ammonium thioglycolate, often referred to as no-lye relaxer, is a milder option that is more versatile and suitable for various hair textures. It also breaks down the hair's internal structure, allowing for straightening, while generally being less damaging than sodium hydroxide.

Recognizing the appropriate application and effects of these relaxers is crucial for cosmetologists to safely and effectively manage different hair types and achieve desirable results in hair texture modification. The other choices listed do not function as hair relaxers. Hydrogen peroxide and glycerin are not used for this purpose; ammonia and bleach are primarily known for lightening hair, and hydrolyzed silk and keratin are conditioning treatments that do not alter hair structure