CeraVe Hydrating Hyaluronic Acid Serum is a lightweight gel serum enriched with Hyaluronic Acid and Vitamin B5, working to provide up to 24 hour hydration. Can be used alone, layered under moisturiser, or as a makeup base. Gentle on skin. Developed With Dermatologists: All CeraVe products have been developed with dermatologists. Active Ingredients: Fortified with Hyaluronic Acid, Vitamin B5 and 3 Essential Ceramides which help to protect the skin’s natural barrier. Formulated with CeraVe’s patented MVE Technology to provide continuous hydration for up to 24 hours.