What is the difference between lye-based relaxers and no-lye relaxers?

• A. Lye relaxers use sodium hydroxide; no-lye relaxers use alternatives such as ammonium thioglycolate or guanidine hydroxide, and they often require a base cream.
• B. Lye relaxers use ammonium thioglycolate; no-lye use sodium hydroxide.
• C. Both use the same active ingredient; differences are cosmetic only.
• D. No-lye relaxers have no chemical processing and are purely cosmetic.

Answer: (A)

The main idea is the chemical used to relax hair and how it’s applied to protect the scalp. Lye-based relaxers rely on sodium hydroxide, a very strong base that raises the hair’s pH to break the disulfide bonds and straighten it. No-lye relaxers avoid sodium hydroxide and instead use alternative reducing agents such as ammonium thioglycolate or guanidine hydroxide. Because these alternatives can be harsher on the scalp, they are often applied with a base cream to create a protective barrier. So, the difference isn’t just cosmetic—it’s about the active ingredient driving the chemical processing and the corresponding scalp protection approach.