Hyaluronic Acid in Skincare

It holds water. Hyaluronic acid is a humectant, which means it pulls moisture in and keeps it sitting in the upper layers of your skin.

That makes skin look plumper and smoother and softens the look of fine lines, but it is doing that by hydrating rather than by changing the skin. Stop using it and the effect fades, which is why it is a maintenance ingredient rather than a treatment.

Despite the name it does not exfoliate. It has nothing in common with glycolic or salicylic acid.

Hyaluronic acid is not really sold by percentage, and you will not find one on most bottles here.

What matters more is molecular size. Smaller molecules sink in further and larger ones sit on the surface holding water there. The better formulas use several sizes together, which is what names like COSRX The Hyaluronic Acid 3 Serum are describing.

Numbers in these product names usually mean something else entirely. A range name, a count of ingredients or a different active altogether.

On damp skin, then seal it. This matters more than which product you buy.

Hyaluronic acid pulls water from whatever is nearest. Applied to damp skin and covered with a moisturiser, it pulls from the water you just added. Applied to bone dry skin with nothing over it, it can pull from deeper in your skin and leave you tighter than before.

So: cleanse, leave your skin slightly damp, apply, then moisturiser straight after. Never skip the moisturiser.

Nearly everything here is a serum, so pick on texture and how much you want to spend.

• A first hyaluronic serum: SkinCeuticals Hydrating B5 Gel or Medik8 Hydr8 B5
• Something richer: Medik8 Hydr8 B5 Intense or SkinCeuticals HA Intensifier Multi-Glycan
• Pure and simple: Image Skincare Ageless Total Pure Hyaluronic Filler or Pestle & Mortar Pure Hyaluronic Serum
• If you would rather it was a cream: Anua PDRN Hyaluronic Acid 100 Moisture Cream or Medicube Hyaluronic Ceramide Jelly Cream

Any of them will hydrate. The expensive ones are buying you texture and the rest of the formula, not more hydration.

It can, and this catches a lot of people out.

If you apply it to dry skin in a dry room and leave it uncovered, it has no water to draw on except your own. Skin then feels tighter than before you started.

The fix is always the same. Damp skin underneath, moisturiser on top. If it still feels tight, what you actually need is a richer moisturiser with oils and ceramides in it, not more hyaluronic acid.

Yes. Hyaluronic acid is the least fussy ingredient in skincare and clashes with nothing.

Use it with vitamin C, retinol, niacinamide or acids without a second thought. It is often a good idea alongside a retinol, because it takes the edge off the dryness.

It goes on early, straight after cleansing and before heavier creams. Thinnest to thickest is the rule.