Florida Cosmetology Licensing ExamChemical ServicesMedium

A client with very fine, fragile hair is requesting a permanent wave. To minimize damage and provide a softer, more natural-looking curl, which active ingredient in acid-balanced perm solutions is commonly recommended?

  1. APotassium hydroxide
  2. BSodium hydroxide
  3. CGlyceryl monothioglycolate (GMTG)
  4. DAmmonium thioglycolate (ATG)
Show answer & explanation

Correct answer: C. Glyceryl monothioglycolate (GMTG)

Glyceryl monothioglycolate (GMTG) is the primary reducing agent in acid-balanced perm solutions. These solutions have a lower pH and are less alkaline than traditional alkaline perms, making them gentler on fine, fragile, or color-treated hair.

Why the other options are wrong

  • A. Potassium hydroxide is also used in some no-lye relaxers, not perms, and is too strong for fragile hair.
  • B. Sodium hydroxide is a strong alkaline ingredient used in lye relaxers, not perms, and would severely damage fine hair.
  • D. Ammonium thioglycolate is the active ingredient in alkaline perms, which are too harsh for fine, fragile hair.

Glyceryl Monothioglycolate (GMTG)

The active ingredient in most acid-balanced permanent waving solutions, known for its gentler action on fine, fragile, or color-treated hair, producing softer, more natural-looking curls.

  • Has a lower pH (typically 4.5-7.0 for true acids, 7.8-8.2 for acid-balanced).
  • Requires heat to process effectively (true acids).
  • Minimizes swelling of hair cuticle, reducing damage.

Memory trick: GMTG is 'G'entle for 'G'ood, 'G'orgeous curls on 'G'ood hair.

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