4D Sodium Hyaluronate Solution is a functional moisturizing ingredient composed of four distinct forms of sodium hyaluronate with varying molecular weights or structural characteristics. By combining Sodium Hyaluronate Crosspolymer, Sodium Hyaluronate, Sodium Acetylated Hyaluronate, and Hydrolyzed Sodium Hyaluronate, this solution simultaneously acts on the skin's surface, stratum corneum, and deeper tissue layers, establishing a multi-level and multi-dimensional hydration and moisture-locking system. Its key characteristic lies in constructing a three-dimensional hydration network across the skin, leveraging the complementary properties of different molecular structures to deliver immediate hydration, long-lasting moisturization, and reinforcement of the skin barrier.