Hyaluronic Acid

Hyaluronic acid is a humectant — a substance that binds water and holds it in the upper layers of the skin. On a label it appears as Hyaluronic Acid or Sodium Hyaluronate.

Why people reach for it. For skin that feels tight and looks dull by evening, and for the sense that cream absorbs without leaving anything behind. Dermatology references describe it as working on the surface layers rather than deep in the skin, and they word the outcomes carefully.

Molecular weight, not percentage. Unlike acids or retinol, the number on the front rarely tells you anything here. Brands more often state how many types of hyaluronic acid a formula contains — different molecular weights sit at different depths of the upper layers. Anua, for example, names eight types in one of its formulas.

One practical note. A humectant pulls water in, so in dry indoor air it works best when something is applied over it to hold that water — a cream or an oil as the final step. On its own, on bare skin, in winter, it does less.

It almost never works alone: in Korean formulas it usually sits next to panthenol, ceramides, collagen or PDRN.