What are the two types of relaxers?

• A. Sodium and Thio
• B. Calcium Hydroxide and Sodium Hydroxide
• C. Ammonium Thioglycolate and Guanidine
• D. Sodium Hydroxide and Thioglycolate

Answer: (A)

Chemical relaxers come in two families: lye-based and no-lye-based. The lye type uses sodium hydroxide as the active ingredient, delivering strong, fast straightening but with a higher potential for scalp irritation. The no-lye type uses a different chemistry (such as guanidine hydroxide formed in situ or calcium hydroxide–based formulations) and is typically gentler on the scalp, with different rinsing and neutralization requirements. Recognizing these two categories helps you match the service to the hair and scalp condition and understand why processing times and aftercare differ. The key idea is that one type is built around sodium hydroxide (the lye option) and the other around a no-lye chemistry like guanidine hydroxide or calcium-based systems.