Product Details Hyaluronic Acid 2% + B5 (Original Formulation) is the original hyaluronic serum from The Ordinary. This rich serum hydrates and gives smoother-looking skin, while working to strengthen the skin barrier. Testing Shows: Replenishes skin hydration Strengthens the skin barrier After 4 weeks: Skin smoothness is enhanced. Elasticity and firmness are boosted.* This formulation contains 4 types of hyaluronic acid and pro-vitamin B5. 4 Types of Hyaluronic Acid: A combination of low-, medium- and high-molecular-weight hyaluronic acid molecules and a next-generation HA crosspolymer support hydration to multiple layers of the skin for a smooth appearance. Pro-vitamin B5 (Panthenol): Supports the formation of essential skin barrier components like ceramides and fatty acids, further improving the skin's moisture retention and an overall healthy appearance. For those who prefer a lighter-textured hyaluronic serum, we recommend exploring Hyaluronic Acid 2% + B5 (with Ceramides). This updated formulation contains an additional form of hyaluronic acid, plus ceramides. It offers instant and long-term hydration with a lightweight feel, while minimising the look of fine lines and wrinkles. *Clinical testing in 34 subjects applying product 2x/day for 4 weeks