What is Moisturizers ? Emollients are cosmetic preparations used for protecting, moisturizing, and lubricating the skin. These functions are normally performed by sebum produced by healthy skin. To moisturize your face, use a moisturizing cream or a natural oil, like olive oil, if you have dry skin. If you have oily skin, use a water-based moisturizing lotion on your face so you don't make your skin more oily.