Ingredient · Hydrator
Hyaluronic Acid: Hydration and How to Use It
Also known as: HA, Sodium hyaluronate
Hyaluronic acid is the most misunderstood ingredient in common use. It does not moisturise skin — it holds water. Where that water comes from depends entirely on how you apply it, and getting that wrong is why some people find it makes their skin tighter rather than softer.
How it works
Hyaluronic acid is a humectant: it binds water and holds it in place. Your skin makes its own, and topical versions add to the supply in the upper layers.
The catch is that a humectant pulls water from wherever it can. In humid air it draws moisture from the environment. In dry air — winter, air conditioning, a plane — it can instead pull water up from deeper in your skin, and if nothing seals it in, that water evaporates. The result is skin that feels tighter after using a hydrating serum.
The rule that fixes it
Apply hyaluronic acid to damp skin, then seal it immediately with a moisturiser.
Damp skin gives the humectant water to grab. The moisturiser on top stops that water evaporating. Miss either half and you get considerably less from it — and in dry conditions you can end up worse off than using nothing.
Molecular weight
High molecular weight hyaluronic acid sits on the surface and holds water there, giving an immediate plumped feel. Low molecular weight penetrates further for longer-lasting hydration.
Products combining several weights cover both. This is one of the few places where the marketing detail reflects something real, though it matters far less than applying it correctly.
What it does not do
- It does not repair the barrier — that is ceramides and lipids.
- It does not treat acne, pigmentation, or fine lines directly.
- It does not replace a moisturiser; it needs one on top to work.
Pairs well with
- Any moisturiser — required, not optional
- Niacinamide — hydration alongside oil regulation
- Retinol and acids — helps offset the dryness they cause
Use with care alongside
- Nothing in particular — it is compatible with essentially everything
Common questions
Why does hyaluronic acid make my skin feel drier?
You are almost certainly applying it to dry skin in dry air, without sealing it. The humectant pulls water from deeper in your skin and it evaporates. Apply to damp skin and follow immediately with moisturiser.
Do I still need a moisturiser?
Yes. Hyaluronic acid holds water; a moisturiser stops it escaping. They do different jobs, and hyaluronic acid without a moisturiser on top is half a step.
Can I use it twice a day?
Yes, morning and night. It does not exfoliate, sensitise, or interact with other actives.
Not sure if hyaluronic acid is right for your skin?
A scan grades what your skin actually needs and builds the routine around it — including which actives to use together and which to keep apart.