High molecular weight hyaluronic acid is a large molecule that stays on the skin's surface rather than penetrating deeply. It binds water and forms a light, hydrating film that makes the skin feel fresher and look smoother almost immediately. This is different from low molecular weight hyaluronic acid, which is broken into smaller pieces and can reach deeper layers.
Because it stays on the surface, high molecular weight hyaluronic acid is less likely to cause irritation and is well suited for normal or combination skin that needs a quick moisture boost. The film it creates also helps limit excess water loss from the skin, which supports softness throughout the day. If you want deeper, longer-term hydration, you could combine this cream with a product containing low molecular weight hyaluronic acid, but for a light daytime moisturiser, the surface-level effect is often enough.