Hyaluronic acid is a moisture-holding molecule your body already makes, and it's found naturally in your skin. In skincare, it works as a humectant: it pulls water into the top layer of your skin, so skin looks and feels plumper, softer and less dry. It works best on damp skin with a moisturizer on top to seal the water in. It's gentle and suits most skin types, but it's a hydrator, not a miracle. Expect softer skin, not a new face.
Hyaluronic acid is on so many labels now that it's easy to assume it does something magical. I get asked about it a lot, usually along with "do I need it?" Here's what it actually does, how to use it so it works, and what it won't do.
What is hyaluronic acid?
Despite the name, it isn't a harsh acid like the ones used for peeling. It's a sugar molecule your body makes on its own, and there's a lot of it in your skin, eyes and joints. Its big talent is holding water. Harvard Health says it can bind more than a thousand times its weight in water.
Your body makes less of it as you get older, which is part of why skin can feel drier and less bouncy with age. On a label you'll often see it as sodium hyaluronate or hydrolyzed hyaluronic acid. These are lab-made forms that work the same way.
What does it do for your skin?
- Draws water in. It's a humectant, the same family as glycerin and aloe. It pulls water into the outer layer of skin.
- Makes skin feel softer and smoother. Well-hydrated skin feels more supple and flexible.
- Softens the look of fine, dry lines. When skin is dehydrated, little lines show more. Adding water back can make them look softer. A dermatologist quoted by Harvard Health put it plainly: it won't bring back youthful plumpness, but after about a week you may notice a mild softening.
- Plays well with others. Using it before stronger ingredients like retinol or glycolic acid may help skin handle them with less dryness.
How to use it so it actually works
This is where most people go wrong. Hyaluronic acid draws in water, so how you put it on matters.
- Wash your face gently.
- Apply it to damp skin. Leave your face a little wet, or mist it, before you smooth on a hyaluronic acid serum.
- Seal it in right away. Follow with a moisturizer that has something to hold the water in, like shea butter, jojoba oil or petrolatum.
- Go thinnest to thickest. Watery serum first, then cream on top.
- Morning, night, or both. Follow the directions on your product.
Skipping the moisturizer is the most common mistake. A humectant needs water to work with, and the cream on top is what keeps that water from escaping. If you're figuring out which cream to put on top, I wrote about choosing a moisturizer for dry skin.
Does the molecule size matter?
A little. Big hyaluronic acid molecules hold more water but stay on the surface. Smaller ones go a bit deeper but hold less. Many serums use a mix of sizes. You don't need to overthink this. How you apply it matters more than which kind you buy.
Is it safe? Who is it for?
It's considered one of the gentlest skincare ingredients. It's rarely irritating and isn't known to cause breakouts, so it suits dry, normal, oily and breakout-prone skin alike. If you do break out after starting a new product, another ingredient in the formula is the more likely cause. As with anything new, patch test first.
Do you need it?
Not necessarily. Hyaluronic acid is a nice ingredient, but it's one of several humectants that do a similar job. Glycerin is the old, simple, inexpensive one, and it's in a lot of good products. The American Academy of Dermatology lists both glycerin and hyaluronic acid among the ingredients to look for in a cream for dry skin.
What matters more than any single ingredient is the routine: a gentle cleanser that doesn't strip, something to add moisture, and something to seal it in, on damp skin, every day. I laid out that whole routine in a simple face routine.
A quick note on injections: hyaluronic acid is also used in cosmetic fillers. That's a medical procedure and a completely different thing from a serum. Fillers should only ever be done by a licensed professional.
So if you love your hyaluronic acid serum, keep it. Just put it on damp skin and follow it with a good moisturizer. That's the part that makes it work.
What we use in our house
The Face System
Oil cleanser, face bar, a plant-oil serum with a touch of glycerin, and our Day + Night Face Moisturizer with shea butter, aloe and goat milk. Four simple steps for skin that feels soft and comfortable, not tight. Made in small batches on our Idaho farm.
See the Face System →
Lauren Stewart makes Tyme Soap by hand on our family farm in Idaho, with milk from our own goats.
