Summary: For repairing a damaged barrier, you ideally need both, as they perform different, complementary jobs. Hyaluronic Acid (like Laneige's Blue HA) provides deep hydration to heal the skin, while Ceramides are lipids that rebuild the "mortar" of the barrier to lock that hydration in.

Comparison: Role in Barrier Repair

Ingredient	Role in Barrier Repair
Hyaluronic Acid (HA)	The Hydrator: A humectant that draws water into the skin cells. This plumps and hydrates the skin from within, which is essential for the healing process.
Ceramides	The Mortar: Lipids that naturally make up over 50% of your skin's barrier. They "fill in the cracks" of a damaged barrier, sealing it to prevent water loss and block out irritants.

Why You Need Both Using only Hyaluronic Acid on a damaged barrier can be ineffective, as the water it provides will just evaporate through the "cracks." Using only Ceramides patches the barrier but doesn't fix the underlying dehydration. A product like the Laneige Water Bank Blue Hyaluronic Cream is effective because it first delivers deep hydration with its micro-sized Blue HA, then seals and repairs the barrier with its ceramide- and panthenol-rich formula.

Don't choose between ceramides and hyaluronic acid; for true barrier repair, buy a product that uses HA to hydrate and ceramides to seal and rebuild.