10 Ingredients to Look For in Your Winter Skin Care, According to the Experts

"Humectants are ingredients that hold water onto and within the skin. Opposite of desiccants (which remove water from something, like salt), these molecules are hydrophilic, meaning they love water and attract water from around them. Among them are hyaluronic acid, urea, and glycerin. Many botanicals and oils can also have humectant properties, with the added benefit of improving skin barrier function, as well." — Carl Thornfeldt, MD

Expert Pick: Neutrogena Norwegian Formula Hand Cream ($5)