What Hyaluronic Acid Actually Does
Hyaluronic acid is a humectant. It draws water molecules toward itself and holds them at the surface of the skin. In a humid environment, it pulls that water from the air around you. In a dry one, with no ambient moisture to draw from, it reaches inward instead, pulling water up from the deeper layers of your skin and releasing it into air that immediately evaporates it. The result is a face that feels tighter an hour after application than it did before you started.
