Calcium thioglycolate trihydrate is primarily used in hair removal products, especially in depilatory creams and lotions. It works by breaking down the disulfide bonds in keratin, the structural protein of hair, which weakens the hair shaft and allows it to be easily removed from the skin surface. This chemical is favored in cosmetic formulations because it effectively dissolves hair with minimal irritation when used at appropriate concentrations. It is also used in some cases for permanent waving of hair, where controlled reduction of hair structure is required. Due to its reducing properties, it must be formulated carefully to maintain stability and skin safety.