Even though soapless skin cleansers use different ingredients from most traditional soap formulas, they still clean your skin in a similar way. To remove dirt and oil from your skin, all cleansers must be able to attract both water and fat. To do this, their molecules have an oil-loving component -- called a lipophilic part -- and a water-loving component -- the hydrophilic part. This combination of lipophilic and hydrophilic elements is called a surfactant.
A surfactant is a detergent that allows water to wash away the oil and dirt from your skin by decreasing the surface tension of water. Surfactants are both lipophilic -- oil loving -- and hydrophilic -- water loving: The lipophilic part captures the dirt and then the hydrophilic part rinses it away. The lipophilic part is typically composed of fatty acids, but in soapless cleansers, it's usually made of chemicals derived from petroleum and other oils, which are less damaging to skin [source: New Zealand Dermatological Society]. In addition, soapless cleansers have more added moisturizers and humectants than most soap, which help prevent skin from drying.
Another reason some traditional bar soaps can be harmful to sensitive skin is because of its high pH -- it can disturb the pH of the outermost layer of skin called the stratum corneum. The stratum corneum protects the inner layers of skin, but when harsh soaps come in contact with it, the soap dries the skin, making the stratum corneum more permeable to chemicals and other pollutants [source: Elias].
Chemical advances in soap and soapless cleansers have given people with sensitive skin many cleansing options. Read on to learn more about the benefits of soapless skin cleansers.