Hyaluronic Acid

Humectant that holds up to 1000x its weight in water.

Also known as: Sodium hyaluronate, hyaluronate, HA, Same name.

What it is

Hyaluronic acid is a naturally occurring polysaccharide found throughout the body, particularly in skin, joints, and connective tissue. In skincare, it's typically used as sodium hyaluronate (the salt form), which is more stable and penetrates better than the acid form.

What it does

It works as a humectant, drawing moisture from the environment and deeper skin layers into the epidermis and binding it there. This plumps the skin, reduces fine lines, and strengthens the skin barrier. It also has mild anti-inflammatory and antioxidant properties that support skin comfort and resilience.

The evidence

Strong clinical evidence supports its hydrating efficacy and safety; multiple studies confirm improved skin hydration, elasticity, and appearance of fine lines with regular use. Evidence is particularly robust for topical application in serums and moisturizers.

Best for

All skin types, especially dehydrated, sensitive, and aging skin; particularly effective for those seeking plumping and fine-line reduction.

Pairs well with

Ceramides, glycerin, peptides, niacinamide, vitamin C, retinol, and other hydrating or active ingredients; layering amplifies hydration and barrier support.

Use cautiously with

No major conflicts; however, in very dry climates without occlusion, HA alone may draw moisture from skin rather than retain it—pair with an occlusive.

Cautions

Generally very safe and non-irritating; no sun-sensitivity, pregnancy concerns, or prescription interactions. Rare allergic reactions possible in sensitive individuals.