The primary chemical in lye-based relaxers is which compound?

• A. Sodium hydroxide
• B. Ammonia
• C. Potassium hydroxide
• D. Calcium hydroxide

Answer: (A)

Lye-based relaxers rely on a very strong base to raise the hair’s pH high enough to break the disulfide bonds and reshape the curl. The primary chemical doing this is sodium hydroxide, which creates the highly alkaline environment necessary for the processing action. Ammonia can be present in some formulas but is not the main active in lye-based relaxers. Potassium hydroxide is another strong base used in different products, but the traditional lye-relaxer centers on sodium hydroxide. Calcium hydroxide is associated with no-lye relaxers (often forming guanidine hydroxide in situ), not the lye-based type. So the correct primary chemical is sodium hydroxide.