Wakes up less puffy — works during the hours the bag is filling, not after it's full
Hyaluronic acid
Sub-villain: the thin, dry skin over the bag. A fluid bag sits under the skin, but what you see is the skin draped over it, and dry skin shows every fold and shadow. Hyaluronic acid holds many times its own weight in water. On top of the skin it's too big to get through and evaporates by morning. In the patch, it's what the nanoneedle tips are made of, so they dissolve into the skin and hold water inside it instead of on it.