The Neutrogena Hydro Boost Hydrating Serum is a lightweight and oil-free serum that provides intense hydration to the skin. It is formulated with hyaluronic acid, which helps replenish and retain moisture in the skin. This serum also contains glycerin, a humectant that attracts moisture to the skin, leaving it feeling soft and supple. With its non-greasy formula, it is suitable for all skin types and can be used alone or under moisturizer.