What is the primary ingredient in most permanent waves?

The primary ingredient in most permanent waves is ammonium thioglycolate. This chemical compound acts as a reducing agent that breaks the disulfide bonds in the hair structure, allowing the hair to be reshaped into the desired curl pattern. The process involves applying the ammonium thioglycolate solution to the hair, which softens and relaxes the hair's natural form, making it conducive to permanent curling when wrapped around rods or curlers.

The effectiveness of ammonium thioglycolate in creating lasting curls is well-established in the field of cosmetology, underpinning its widespread use in perm solutions. Other ingredients, such as hydrogen peroxide, may be included in the perm process as an oxidizing agent, but they do not serve as the primary active ingredient for curl formation. Glycerin and alcohol are often used in various hair products for moisturizing or stabilizing properties, but they do not play a central role in the actual process of perming hair.