California Cosmetology Written ExamChemical Texture ServicesHard

A client wants to switch from sodium hydroxide relaxers to a 'no-lye' relaxer system due to scalp sensitivity. How does a guanidine hydroxide (no-lye) relaxer typically differ in application from a sodium hydroxide relaxer?

  1. AGuanidine hydroxide relaxers are mixed just before application by combining a guanidine carbonate cream with a calcium hydroxide activator
  2. BGuanidine hydroxide relaxers use the same base cream protective step as sodium hydroxide relaxers but skip lanthionization
  3. CGuanidine hydroxide relaxers have a lower pH than thio relaxers and require no neutralizing step
  4. DGuanidine hydroxide relaxers are pre-mixed and never require combining two components before use
Show answer & explanation

Correct answer: A. Guanidine hydroxide relaxers are mixed just before application by combining a guanidine carbonate cream with a calcium hydroxide activator

No-lye (guanidine hydroxide) relaxers are two-part systems mixed immediately before use, combining a guanidine carbonate cream with a calcium hydroxide activator, which react to form guanidine hydroxide; this differs from sodium hydroxide relaxers, which are typically pre-mixed and ready to use. No-lye relaxers still work through lanthionization and require thorough neutralizing shampoo afterward.

Why the other options are wrong

  • B. No-lye relaxers still work via lanthionization like other hydroxide relaxers.
  • C. No-lye relaxers still have a high pH (similar to hydroxide relaxers) and do require neutralizing shampoo.
  • D. No-lye relaxers require mixing two components immediately before use, unlike ready-to-use sodium hydroxide relaxers.

No-Lye (Guanidine Hydroxide) Relaxer

A two-part hydroxide relaxer system mixed immediately before use by combining guanidine carbonate cream with a calcium hydroxide activator, marketed as gentler on the scalp.

  • Mixed fresh right before application (two components)
  • Still works via lanthionization, high pH
  • Requires thorough neutralizing shampoo, not oxidation

Memory trick: No-lye is a two-part cocktail—mix carbonate cream and calcium activator fresh, like mixing paint before painting.

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