Ammonium Persulfate

Ammonium persulfate is an inorganic salt that functions as a potent oxidising agent. It is commonly found in hair lightening and bleaching products, where it works to break down melanin and lift colour from hair. In skincare, its presence is typically incidental rather than intentional, as it is not a primary active ingredient for facial or body skin treatments.

This ingredient is most recognised in professional salon products and at-home hair colour systems, where it can be present at concentrations up to 60% in some formulations. It is occasionally encountered in other industrial and cosmetic applications where oxidising capacity is required.

Ammonium persulfate works by releasing oxygen radicals when activated, typically by mixing with other components in a hair bleach formulation. These radicals penetrate the hair shaft and break down the chemical bonds that give hair its colour, thereby lightening it.

The oxidising action is powerful and non-selective, which is why the ingredient is effective for lightening but also why careful formulation and use instructions are essential to minimise potential irritation.

Ammonium persulfate is not typically applied directly to the face or body in skincare formulations. If encountered in a product (such as a specialised treatment), always follow product instructions carefully, perform a patch test first, and avoid contact with eyes. Those with a history of sensitive skin or contact dermatitis should exercise particular caution.