Sodium Thioglycolate
molecular structure · PubChem
AKA: 367-51-1, Sodium mercaptoacetate, Mercaptoacetic acid sodium salt, Sodium thioglycollate, Thioglycolate sodium, Mercaptoacetic acid, Sodium salt, Sodium sulfanylacetate, Sodium 2-mercatoethanoate, Thioglycollic acid
Synthetic
Antioxidant
Medicated Active
Not Clean
Based on the available data, the CIR Expert Panel concluded that ... Sodium Thioglycolate is safe for use in hair straighteners, permanent waves, tonics, dressings, and so forth, wave sets, other non-coloring hair products, and hair dyes and colors, as described in this safety assessment, at concentrations up to 15.2% (as Thioglycolic Acid). Hairdressers should avoid skin contact and minimize consumer skin exposure. Sodium Thioglycolate in depilatories is safe when formulated to be non-irritating under conditions of recommended use.
Solubility Very soluble (NTP, 1992)
Formula
C2H3NaO2S
Mol. Weight
114.10
CAS #
367-51-1
Form
Powder
State
Thioglycolic acid, sodium salt is a white powder with a slight odor. Used in cold-waving of hair and as a dipilatory.
Functions
Antioxidant
Fights free radicals — the unstable molecules from UV, pollution, and stress that break down collagen and cause premature aging.
Depilatory
Hair Waving Or Straightening
Reducing
Neutralizes Free Radicals
Traditional Use
Developed in the mid-20th century as a chemical reducing agent for hair relaxation and permanent wave treatments. It replaced older, more caustic methods of breaking down hair protein bonds and became the standard ingredient in chemical hair straightening products.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
Caution
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed1 review →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR