Displaying 5 results of Thioctic Acid Impurities Thioctic acid, also known as alpha-lipoic acid, is an antioxidant that is commonly used in dietary supplements and skin care products. However, the purity of thioctic acid can vary, and impurities can be present. These impurities can affect the efficacy and safety of thioctic acid products. Common thioctic acid impurities include heavy metals, residual solvents, and other organic compounds. Manufacturers must ensure that their thioctic acid products are pure and free from harmful impurities.