Which perm type uses glyceryl monothioglycolate as part of its solution to break bonds?

• A. Acid perms
• B. Alkaline perms
• C. Neutral perms
• D. Thermal perms

Answer: (A)

The key idea is how the perm solution chemically reduces the bonds in hair so it can be reshaped. Glyceryl monothioglycolate is a reducing agent used in acid perms. In the mildly acidic environment of an acid wave, GMTG effectively breaks the disulfide bonds in the hair’s keratin, allowing the hair to be rearranged around rods into the desired curl or straighten pattern. After the hair is wrapped, a neutralizer oxidizes the thiol groups, reforming disulfide bonds in the new configuration to set the shape.

Different perm types use different reducing agents or conditions. Alkaline perms rely on a stronger reducing agent like ammonium thioglycolate and operate at higher pH, while neutral perms use other agents and aim for a neutral pH with milder reduction. Thermal perms depend more on heat to guide bond rearrangement rather than GMTG chemistry.