MERCAPTOPROPIONIC ACID is graded A (Safe) by Expert·ING, based on COSING regulatory data.
MERCAPTOPROPIONIC ACID
Safety grade: A
This is a chemical compound that works by breaking down the protein structure in hair, making it easier to remove or reshape. It's commonly used in hair removal creams and treatments that straighten or permanently wave hair.
This reducing agent breaks chemical bonds in hair protein, enabling it to be removed during depilation or reshaped during permanent waving or straightening treatments.
Graded using: COSING.
Last verified: May 26, 2026
Other Reducing ingredients
- SODIUM METABISULFITE — Grade B
- THIOGLYCERIN — Grade A
- STANNOUS CHLORIDE — Grade A**
- DIHYDROXYACETONE — Grade A
- SODIUM THIOSULFATE — Grade A
- GLUTATHIONE — Grade A
- THIOLACTIC ACID — Grade A
- SODIUM BISULFITE — Grade B**