Cosmetic ingredient

THIOLACTIC ACID

Thiolactic Acid, listed as THIOLACTIC ACID, is a sulfur-containing organic compound. Its structure combines an acidic part with a thiol group — the sulfur-and-hydrogen group — so it behaves differently from acids used only to adjust pH or exfoliate skin.

INCITH1 products
CAS number
79-42-5
EC number
201-206-5
Chemical name
2-Mercaptopropionic acid

THIOLACTIC ACID: what it is

Thiolactic Acid, listed as THIOLACTIC ACID, is a sulfur-containing organic compound. Its structure combines an acidic part with a thiol group — the sulfur-and-hydrogen group — so it behaves differently from acids used only to adjust pH or exfoliate skin.

Its name can be confused with lactic acid, but they are not the same substance: the thiol group is the important chemical difference. It is also called 2-mercaptopropionic acid in chemistry references, which helps identify the same compound when it appears outside a cosmetic label.

THIOLACTIC ACID: what it does in cosmetics

Thiolactic Acid is listed for uses that temporarily alter the hair fibre, including waving or straightening. As a reducing agent, it takes part in a chemical step that makes some sulfur links in keratin easier to rearrange; that change in the fibre, rather than ordinary conditioning, makes it possible to work with hair shape.

It is also associated with depilatory products, which act on the hair already above the skin rather than on the root. Its antioxidant and fragrance categories do not support expecting skin hydration, dark-spot treatment, or an anti-ageing effect; its practical interest lies chiefly in these specific chemical applications for hair.

THIOLACTIC ACID: conditions and care

GHS data for the substance indicate acute toxicity if swallowed or in contact with skin, as well as a danger of severe skin burns and eye damage. These classifications concern the substance and do not by themselves define the risk of a finished cosmetic; do not handle the raw material and follow the product instructions.

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Products containing this ingredient

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