SLES is the abbreviation for Sodium Laureth Sulfate. These can bind oil-based dirt from the skin and make it easier to wash off. Due to their cleansing effect, they are found in many care products and are mainly used for foam formation. However, Sodium Laureth Sulfate is now considered controversial because it can have an excessively strong effect and potentially dry out the skin. If a product is labelled “Free from SLES”, it does not contain any Sodium Laureth Sulfate.