Hyaluronic acid is everywhere. Every brand has an HA serum now, and the marketing makes it sound foolproof — just slap it on and enjoy plump, dewy skin. But HA is one of those ingredients where how you use it matters just as much as whether you use it. And a lot of people are getting it wrong.
1. Applying it to dry skin
This is the big one. Hyaluronic acid is a humectant — it works by pulling moisture towards itself. It can hold up to 1,000 times its weight in water, which sounds incredible until you realise it doesn't generate that moisture from nowhere. It has to pull it from somewhere.
If you apply HA to dry skin in a dry room, it'll pull moisture from the deeper layers of your skin instead of from the environment. That's the opposite of what you want. Always apply HA to damp skin — right after cleansing, while your face is still wet, or spritz with a face mist first. Then seal it in with a moisturiser.
2. Using it in dry climates without an occlusive
Related to mistake number one, but worth its own point. If you live somewhere with low humidity — or you're blasting central heating all winter — HA without an occlusive on top is a recipe for tighter, drier skin. The moisture it draws in will just evaporate.
Always follow HA with something that creates a physical barrier. Ceramide-rich moisturisers, squalane, even a thin layer of something with petrolatum if your skin tolerates it. The HA pulls moisture in; the occlusive keeps it there.
3. Assuming bigger molecules are better
HA comes in different molecular weights, and there's a common misconception that you should always go for the highest weight because "bigger molecules hold more water." It's more nuanced than that. High molecular weight HA sits on the surface and provides immediate plumping. Low molecular weight HA penetrates deeper and hydrates from within. The best formulations actually use a blend of multiple weights — you'll sometimes see this labelled as "multi-weight" or "multi-molecular" on packaging.
4. Layering too many HA products
HA toner, HA serum, HA moisturiser, HA mask. Some routines have become absurdly HA-heavy, and there's genuinely no benefit to that. Your skin can only hold so much water. Past a certain point, you're just layering sticky texture for no reason and potentially making other products absorb less effectively.
One well-formulated HA product is plenty. Pick a serum or a moisturiser that contains it — you don't need it in every step.
5. Skipping it because your skin is oily
"My skin's already oily, I don't need more moisture." This one comes up constantly and it's a misunderstanding of how skin works. Oily skin produces excess sebum, but it can still be dehydrated — lacking water as opposed to oil. Dehydrated oily skin often overproduces sebum to compensate for the water it's missing.
HA provides hydration without adding oil. It's lightweight, non- comedogenic, and can actually help balance oily skin over time by giving it the water content it's craving. If your oily skin feels tight after cleansing, that's dehydration talking.
Curious how different HA products stack up? Have a look at our hyaluronic acid ingredient page to see which products feature it prominently and where it actually sits in their formulas. Because INCI position matters — an HA serum where hyaluronic acid is the 15th ingredient isn't really an HA serum.