Hair coloring products containing metallic salts are not compatible with which relaxer type?

• A. Thio relaxers
• B. Lye relaxers
• C. Guanidine relaxers
• D. Ammonia relaxers

Answer: (A)

Metallic salts in hair color leave metal ions that can react with the reducing agent used in thio relaxers (the thioglycolate-based system). That interaction can disrupt the reduction of disulfide bonds, leading to unpredictable results, including uneven processing, hair damage, or scalp irritation. Other relaxer chemistries (lye, guanidine, ammonia) don’t rely on the same thiol reduction, so the problematic reaction with metallic salts doesn’t occur in the same way. So, metallic-salt colors are not compatible with thio relaxers.