A range of different acids can be used to achieve different results, some of the most common are: Glycolic Acid – Exfoliates skin & reduces pigment Salicylic Acid – Cleans out pores & reduces oil on skin Lactic Acid – Brightens skin Mandelic Acid – Exfoliates skin & speeds up cell turnover Ascorbic Acid – Brightens & strengthens skin Many peels also contain other active ingredients such as plant stem cells and vitamins.