Hyaluronic acid is a powerful humectant, meaning it attracts and retains moisture from the environment. This helps to hydrate and plump the skin, improving skin elasticity and reducing the appearance of fine lines and wrinkles. The Kiehl's 1.5% hyaluronic Acid serum is formulated with only 7 ingredients, helping to improve skin absorption and efficacy. Experience the benefits of hyaluronic acid now in his concentrated hyaluronic acid face serum.