THIOGLYCERIN
Thioglycerin is a small sulfur-containing organic substance, also known as 3-mercaptopropane-1,2-diol. That chemical name describes a three-carbon chain with two alcohol groups and one thiol group, the sulfur-containing part that accounts for its reducing behavior. It is not ordinary glycerin: adding sulfur changes the molecule's reactivity substantially.
THIOGLYCERIN: what it is
Thioglycerin is a small sulfur-containing organic substance, also known as 3-mercaptopropane-1,2-diol. That chemical name describes a three-carbon chain with two alcohol groups and one thiol group, the sulfur-containing part that accounts for its reducing behavior. It is not ordinary glycerin: adding sulfur changes the molecule's reactivity substantially.
Its name can be confused with thioglycolic acid, yet they are different substances. Thioglycerin has been described in cold-wave preparations and appears in cosmetic-ingredient inventories for uses involving keratin, the protein that makes up hair fibers and the outermost layer of skin. Its presence on a label therefore points to a chemical transformation purpose rather than the usual role of a simple moisturizer.
THIOGLYCERIN: what it does in cosmetics
In hair waving or straightening products, thioglycerin works as a reducing agent: it takes part in the step that makes certain keratin bonds more open to a change in shape. In practical terms, this lets a professional preparation work on curl pattern or alignment before the new shape is set.
It has also been used in depilatory creams and may act as a keratolytic. In that setting, the aim is to weaken the keratin material of the hair so removal is easier; it is not a treatment for skin, acne, or dark spots. The historical records found concern purpose-made preparations, not a demonstrated daily-care benefit or a result from thioglycerin alone in every formula.
THIOGLYCERIN: conditions and care
The pure substance carries hazard classifications for skin contact and eye irritation. A historical clinical report also described allergic eczema from thioglycerin in depilatory creams; products made for this purpose require strict use according to their directions and should be stopped if a reaction occurs.
Products containing this ingredient
See which products include it and the name used in each composition.
