If your skin is feeling tight, dull or thirsty, hyaluronic acid is the ingredient your routine has been missing. This ultra-lightweight humectant acts like a moisture magnet, drawing water into your skin for a plumper, softer, more radiant-looking complexion. K-beauty formulas often layer multi-molecular-weight HA so hydration reaches both the surface and deeper-looking layers of skin, giving you that signature Korean bounce. Our edit brings together the best hydrating toners, essences, serums, creams and sheet masks from the K-beauty world.