The Obagi Foaming Gel Cleanaser, Obagi Gentle Cleanser, and Toner are sold as part of the Nu-Derm Systems or they can be purchased separately. This Prepare Step cleans and tones the skin, removing impurities, dead skin cells, and bacteria and prepares it for the steps that follow. This step is accomplished without skin irritation. At the completion of this step, the skin is returned to its normal pH level.