Lye relaxers are composed of which chemical?

• A. Sodium hydroxide relaxers
• B. Calcium hydroxide relaxers
• C. Potassium hydroxide relaxers
• D. Ammonium hydroxide relaxers

Answer: (A)

Lye relaxers rely on a strong base to raise the hair’s pH and cleave the disulfide bonds that give hair its shape, allowing the strands to slip into a straightened form. The classic, recognizable lye relaxer uses sodium hydroxide as that active ingredient. While calcium hydroxide and potassium hydroxide are also bases used in some hair-relaxing or perming formulations, they are associated with no-lye systems or different products, and ammonium hydroxide isn’t the standard active in lye relaxers either. So the chemical that defines a lye relaxer is sodium hydroxide, making it the best answer.