Humectant
Hyaluronic Acid
Also: Sodium Hyaluronate · HA
A humectant your skin already manufactures. Tops up hydration without weight. Best used in multi-weight form.
What it is
A naturally-occurring polysaccharide present throughout the body — connective tissue, joints, eyes, and skin. Synthesised topically through bacterial fermentation. Holds up to 1,000× its weight in water.
How it works
Pulls water from the surrounding environment (or from deeper layers of your own skin) into the upper layers of the stratum corneum. Multi-weight versions matter: high molecular weight HA sits on the surface forming a hydrating film; low molecular weight HA penetrates deeper for plumping.
Who it is for
Every skin type. Particularly transformative for dehydrated skin (which can occur in oily, acne-prone people too — dehydration is a water-content issue, not an oil-content one).
What to watch for
Apply to damp, not dry, skin — HA needs water to draw from. In very dry environments, layer a moisturiser over the HA to seal the moisture in.
Found in