Final answer:
The main ingredient in curl rearrangers is thioglycolic acid or its derivatives, used to break down disulfide bonds in hair for reshaping. Followed by a neutralizing solution, the hair is set into a new shape.
Step-by-step explanation:
The main ingredient found in curl rearrangers is typically a chemical called thioglycolic acid or its derivatives. Curl rearrangers, which are also known as perm or permanent wave solutions, work by breaking down the disulfide bonds in hair keratin, which allows the hair to take on a new shape. This process is often referred to as a chemical perm. Thioglycolic acid is the key component because it helps to soften the hair's structure, thus making it more malleable for styling into curls or waves.
Curl rearrangers come as part of a two-step process. Firstly, the thioglycolic acid-based solution is applied to the hair to break down the bonds. Next, after the hair has been reshaped, a neutralizing solution is applied, which reforms the disulfide bonds in their new position, thereby 'fixing' the hair into its new shape. This is why it's important to follow the instructions provided with the product carefully to achieve the desired results.