Which type of relaxer requires a neutralizer to be applied?

A thio relaxer requires a neutralizer to be applied because it is based on ammonium thioglycolate, which modifies the hair's disulfide bonds. When the thio relaxer is applied to the hair, it opens the cuticle and penetrates the hair shaft to break the sturdy disulfide bonds that give hair its texture. After the desired level of straightening is achieved, a neutralizer must be applied to re-form these bonds in a new, straightened position. The neutralizer helps to restore the pH balance of the hair and to maintain the integrity of the hair’s structure after the relaxing process.

The neutralization process is essential because if it is not applied, the hair could potentially revert back to its original texture or sustain damage. This highlights the importance of following the chemical relaxing process with a proper neutralizing step for effective and safe styling results.