Sodium lauryl sulfate (SLS) is a chemical compound that is commonly used in personal care and cleaning products, such as body washes, detergents, cleansers, shampoos, handwashes and toothpastes. SLS is what’s known as a surfactant—that means it reduces the surface tension between ingredients in a product. It can be made synthetically or naturally, and it’s what gives cleaning products that foamy, bubbly consistency most of us have come to expect.