What does hyaluronic acid do for your skin?
Hyaluronic acid is a humectant, which means it attracts and holds on to water. On your skin, it mostly works at the surface, helping skin feel hydrated and look plumper for a while. It's well tolerated by most people, and it works best when you seal it in with a moisturiser. It isn't a filler in a bottle.
What it is
Your skin already makes it. According to one recent paper, skin holds about half of all the hyaluronic acid in your body, mostly in the deeper layer, where it helps hold water. The ingredient in a jar is a manufactured version of the same molecule.
What it does when you put it on
Think of it as a sponge at the surface. It takes up water, which softens the very top layer of skin and can make it look smoother and plumper for a while. That effect is real but limited. It doesn't replace the hyaluronic acid deeper down, and it doesn't work like an injected filler.
Do molecule sizes matter?
You'll see "low molecular weight" and "multi-weight" on labels. The idea is that small molecules can get further into skin. A study of creams at five different molecular weights found all of them improved hydration and elasticity compared with a placebo, and only the smaller ones showed a significant change in wrinkle depth. That's encouraging for the idea, but it's one study with a 0.1 per cent cream used every day, so it doesn't tell you much about a mask worn for 15 minutes.
Our Hyaluronic Acid label says Hyaluronic Acid, and Rose lists sodium hyaluronate, a salt form of it. Neither gives a molecular weight, so we can't tell you which size it is. If that matters to you, ask the same question of any product you're considering. Plenty of them make the claim without saying what they tested.
Does hyaluronic acid dry your skin in dry air?
You'll see this claim a lot: in dry air, humectants pull water up from deeper skin and leave you drier. It sounds logical, but we couldn't find a good study showing it happens in everyday use. DermNet describes humectants as attracting and holding water in the top layer of skin, and notes that occlusive moisturisers work differently, by slowing the loss of water to the air.
The practical advice is the same either way: put your hyaluronic acid on damp skin, and put a moisturiser over it. That matters more in winter, on planes, and next to a heat pump.
How to use it
- Apply it to clean, slightly damp skin.
- Follow with a moisturiser while your skin is still damp.
- In the morning, finish with sunscreen.
It generally plays well with other products, including niacinamide and retinol, which makes it an easy place to start if you're building a routine. For where it goes, see skincare routine order.
Hyaluronic acid in our jars
Hyaluronic Acid is the formula built around it, for skin that feels tight and thirsty: Hyaluronic Acid is eighth on its label. Rose has it too, as sodium hyaluronate. The shop page describes it like this: it "holds water at the surface for a plumper, hydrated look". What you'll notice is short term: skin that feels comfortable rather than tight straight after you peel, and a plumper, dewy look. Following with a moisturiser helps keep that feeling.
Questions
Is hyaluronic acid an acid that exfoliates?
No. Despite the name, it isn't an exfoliating acid like glycolic or salicylic acid. It holds water rather than loosening skin cells.
Can you use hyaluronic acid every day?
Most people can. It's a common ingredient in daily serums and moisturisers. Stop if your skin reacts, as with any product.
Can I use hyaluronic acid with retinol?
Generally, yes. It's a common pairing because hydrating ingredients can help with the dryness retinol can cause. If you're using a prescribed retinoid, check with whoever prescribed it.
This is general information, not medical advice. If you're worried about your skin, see your GP or a skin specialist.
Sources
- Multicenter evaluation of a topical hyaluronic acid serum, Robinson and colleagues, Journal of Cosmetic Dermatology, 2022
- Efficacy of cream-based novel formulations of hyaluronic acid of different molecular weights in anti-wrinkle treatment, Pavicic and colleagues, Journal of Drugs in Dermatology, 2011
- Emollients and moisturisers, DermNet