The formula of this Erno Laszlo moisturizing cleansing oil uses hydrogenated polyisobutene, a versatile emollient and a great replacement for old-fashioned mineral oil, a once common skin cleanser. Instead of mineral oil, hydrogenated polyisobutene works together with three hydrophobic esters (Neopentyl Glycol Dicaprylate/Dicaprate, Tridecyl Stearate and Tridecyl Trimellitate) to remove dirt and debris from the skin. This oil cleanser works best when combined with the cleansing bar of your choice as part of the Double Cleanse method developed by Dr. Laszlo.