Hyaluronic acid is in almost everything now — toners, essences, serums, moisturizers — which leads to a fair question shoppers keep asking: what does it actually do, and do you really need a separate hyaluronic acid serum on top of everything else?
This guide clears up what hyaluronic acid is, the myths people get wrong, and how to tell whether a dedicated serum belongs in your routine.
What is hyaluronic acid and what does it do?
Hyaluronic acid is a humectant, meaning it attracts and holds water, and it occurs naturally in your skin. In skincare it is used to help skin hold onto moisture so it feels hydrated, soft, and looks plumper. Despite the word "acid" in its name, it is not an exfoliant and does not work like an AHA or BHA — it is a hydrating ingredient, not a resurfacing one.
What do people get wrong about hyaluronic acid?
Most of the confusion comes from a few common myths:
- "It exfoliates because it is an acid." It does not. The name is chemistry, not function — hyaluronic acid hydrates rather than exfoliates.
- "More is always better." A higher percentage is not automatically more hydrating, and very high amounts are not what makes a formula feel good.
- "It hydrates on its own in any weather." In very dry air, hyaluronic acid can pull water from wherever it can find it. Applying it to damp skin and sealing with a moisturizer is what keeps that water in.
- "It is only for dry skin." Because it is lightweight, hyaluronic acid suits oily and combination skin too, not just dry skin.
Do you need a separate hyaluronic acid serum?
Not necessarily. Hyaluronic acid is already included in many toners, essences, and moisturizers, so if the products you use list it, you may already be getting it without a standalone serum. A dedicated hyaluronic acid serum is an optional extra step rather than a must-have, and layering one on top of products that already contain it is not required for most people.
Who might still want a dedicated serum?
A separate hyaluronic acid serum can make sense if your skin feels persistently dehydrated, if you enjoy layering thin hydrating steps, or if you want one targeted step you can adjust independently. It is about preference and how your skin feels, not a rule everyone has to follow.
How do you use hyaluronic acid so it actually hydrates?
The simplest way to get the most from hyaluronic acid is to apply it to slightly damp skin and then follow with a moisturizer to seal the hydration in. This is true whether the hyaluronic acid comes from a serum, a toner, or a cream. Using it as a hydrating layer under your moisturizer, rather than as the last step on its own, is what helps skin stay comfortable through the day.
Which Klairs products include hyaluronic acid?
If you would rather get hyaluronic acid through steps you already use, several Klairs products include it:
- The fragrance-free Supple Preparation Unscented Toner uses sodium hyaluronate as a lightweight, hydrating first step.
- The Vitamin Toning Barrier Cream pairs triple hyaluronic acid with barrier-supporting ingredients in a daily moisturizer.
- The Midnight Blue Calming Cream includes a hyaluronic acid complex in a lightweight, calming gel-cream.
If you are building out a hydrating routine, our guides to choosing a milky or hydrating toner and the best toner for dry skin cover the toner step in more detail.
FAQ
What does hyaluronic acid do for skin?
Hyaluronic acid is a humectant that attracts and holds water, helping skin feel hydrated and soft and look plumper. It occurs naturally in the skin and is used across toners, serums, and moisturizers as a hydrating ingredient.
Is hyaluronic acid an exfoliating acid?
No. Despite the word acid in its name, hyaluronic acid does not exfoliate the way AHAs or BHAs do. It is a hydrating ingredient that helps skin hold onto moisture, not a resurfacing one.
Do I need a separate hyaluronic acid serum?
Not necessarily. Hyaluronic acid is already in many toners, essences, and moisturizers, so if your current products contain it you may not need a standalone serum. A dedicated serum is an optional extra rather than a requirement.
Can hyaluronic acid dry out your skin?
In very dry air, hyaluronic acid can draw water from wherever it can, which is why applying it to damp skin and sealing with a moisturizer matters. Used that way, it helps skin stay hydrated rather than feeling drier.
Is hyaluronic acid good for all skin types?
Yes, because it is lightweight it can suit oily and combination skin as well as dry skin. As always, patch test a new product first if your skin is easily irritated.
The simple takeaway
Hyaluronic acid is a gentle, hydrating ingredient that helps skin hold water — not an exfoliating acid, and not something everyone needs in a separate serum. Check whether your toner or moisturizer already includes it, apply it to damp skin, and seal with a moisturizer. That is usually all it takes to keep skin feeling comfortably hydrated.
