Moisturisers are ingredients that increase the moisture content of the skin, and help to maintain the skin barrier. The main categories of moisturising ingredients are emollients, humectants and occlusive agents. Emollients smooth and soften the skin surface. Examples of emollients include dimethicone and plant and mineral oils. Humectants draw water into the skin, increasing its moisture content. Examples include glycerine, propylene glycol, urea, hyaluronic acid and alpha hydroxy acids. Occlusives reduce water loss through the skin, and include petroleum jelly, lanolin, mineral oil and silicones.
For more information, see the blog post All About Moisturisers.
