What Is Hyaluronic Acid? — The Complete Guide
Hyaluronic acid is the most-misused humectant in skincare. Used right, it's the cheapest plumping ingredient on the shelf.
The science.
Hyaluronic acid is a naturally-occurring sugar molecule found in skin, joints, and connective tissue. Topical hyaluronic acid binds water to skin, plumping it temporarily and supporting hydration.
How it works
HA molecules bind water — up to 1000× their weight. Larger molecules sit on the surface; smaller penetrate deeper. The combination of multiple molecular weights delivers plumping at multiple skin layers.
Right for which skin types?
All skin types. Particularly good for dehydrated, mature, post-procedure, and dry skin.
How to use it
Apply to damp skin before moisturiser. Two to three drops. In dry climates, seal with moisturiser immediately or HA will pull water from your dermis instead of binding to it.
Side effects
Almost none. Rare allergy. Not increases UV sensitivity.
Top recommendations.
- Hyaluronic Acid 2% + B5 by The Ordinary — $13 · Category benchmark
- HA Intensifier by SkinCeuticals — $165 · Clinical-grade
- Hyaluron + Marine Booster by Hada Labo — $30 · Japanese-formula
Common questions.
Should I apply HA to wet or dry skin?
Damp. HA pulls water from whatever's nearest — apply to wet skin and seal immediately.
How often can I use HA?
Twice daily, indefinitely. No tolerance ceiling.
Is HA the same as sodium hyaluronate?
Sodium hyaluronate is the salt form, with smaller molecules. Most products use both.