Neutrogena Hydro Boost Ultra-Hydrating Serum uses Hyaluronic Acid alongside natural moisturising factors to deeply replenish the skin. This fast-absorbing formula delivers intense, weightless hydration instantly and maintains it for up to 72 hours. It is specifically designed to enhance skin radiance and strengthen the skin's natural barrier function over time. This nourishing serum ensures continuous moisture replenishment for visibly healthier skin.