What each key ingredient does Hyaluronic Acid is a naturally occurring compound in the skin that attracts water molecules. It is a humectant that holds up to 1,000 times its weight in water, helping to replenish and maintain skin moisture levels. YEOUTH Pure 100% Hyaluronic Acid serum is a gentle hydrating serum designed to moisturize the skin. Hyaluronic acid is a natural substance found in the body that helps retain moisture, but its levels decrease as we age, leading to dryness and fine lines. Happy skin is well-hydrated skin! The YEOUTH Pure Hyaluronic Acid face serum for dry skin provides deep hydration, enhancing its moisture levels and suppleness. With its gentle formula, this face serum can also improve the appearance of fine lines, resulting in a smoother, softer, and more youthful-looking complexion.