Sodium Hyaluronate.

What it does

In skincare it draws and holds moisture in the upper layers for instant, plumping hydration, and is more stable and easier to formulate than hyaluronic acid itself.

Benefits

• Pulls water into the skin for immediate hydration and a plumper look
• Holds large amounts of water (up to ~1000x its weight) to soften and smooth
• Naturally skin-identical and suitable for almost all skin types
• More stable and formula-friendly than plain hyaluronic acid

Side effects

• Very low risk; non-irritating and non-comedogenic in topical use
• In very dry climates can pull moisture from skin if not sealed with a moisturizer

Who it's for

All skin types, especially dehydrated, dry, or tight-feeling skin

Who should be careful

No notable cautions for topical use; in arid air, layer over damp skin and seal with a cream

• Hyaluronic acid - Wikipedia