There are two types of relaxers which include:

Sodium hydroxide Ammonium thioglycolate

Sodium Hydroxide

Sodium hydroxide relaxers, which are considered to be caustic relaxers, are designed to soften and swell the hair's fibers.

As the solution penetrates into the cortex of the hair, the cross-bonds (sulfur and hydrogen) are broken. The action of the comb, the brush or the hands in smoothing the hair and distributing the chemical, straightens and softens the hair.

Manufacturers vary the sodium hydroxide content of the solution from 5% to 10% and the pH factor between 10 and 14.

In general, the more sodium hydroxide used and the higher the pH, the quicker the chemical reaction will take place on the hair, and the greater the danger will be of hair damage.

Ammonium Thioglycolate

Ammonium thioglycolate is a chemical compound made up of ammonia and thioglycolate acid. It is the main active ingredient in both chemical hair relaxers and chemical perms.

Although ammonium thioglycolate which is also referred to as a "thio" is less drastic in its action than sodium hydroxide, it soften and relaxes overly curly hair in somewhat the same manner.