COSRX
The Hyaluronic Acid 3 Serum
A hyaluronic acid serum for skin that still feels tight an hour after moisturizer, worn after toner and under cream. 20 ml.
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- Suited to
- DryDehydratedSensitiveCompromised barrier
- Helps with
- DehydrationBarrier weaknessEarly environmental damageRough surface texture
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- 30-day returns
- Free US shipping on orders of $100 or more
- Dispatched within 2 business days
How it works
Hydration is a layering job, and this is the water step that sits between toner and moisturizer. It goes on damp skin so the layer above it has something to hold, and the cream over the top is what keeps it there. Skin that drinks a moisturizer and still feels tight an hour later is usually short of water rather than oil, and that gap is what this step is for. It is a daily step, morning and evening, and it layers under anything else already in the routine. In the morning it goes under sunscreen, and at night under whatever cream finishes the routine.
Key benefits
- Sodium hyaluronate is fifth on the list, ahead of the amino acid blend
- COSRX's own product name states 3%; the ingredient list itself declares no percentage
- Ceramide NP, cholesterol and phytosphingosine round out a barrier-supportive base further down the list
- A small amount of lactic acid sits near the end for mild surface exfoliation, not a treatment-level dose
- Watery texture built to layer, not to replace a moisturizer
- 20 ml, a layering-serum size rather than an all-over daily pour
Key actives
Sodium Hyaluronate
a humectant that draws in and holds moisture
Ceramide NP
supports the skin barrier alongside the hydrators
COSRX The Hyaluronic Acid 3 Serum
What is the actual sodium hyaluronate content in this Hyaluronic Acid 3 Serum?
Sodium hyaluronate sits fifth on the ingredient list, right after the water, butylene glycol, propanediol and glycerin base, though the list itself declares no percentage there, and the 3% figure comes from the product name only. Ceramide NP, cholesterol and phytosphingosine appear further down the list as a barrier-supportive trio, and a broad amino acid set rounds out the formula. This is a 20 ml bottle sized for layering rather than an all-over daily pour.
Is this serum suitable for dry, barrier-compromised skin?
Ceramide NP, cholesterol and phytosphingosine appear together on the list, the same three-lipid combination often chosen to support a weakened barrier, alongside sodium PCA and sodium lactate. Fragrance, essential oil, paraben and mineral oil are all absent from the list. That reads as a generally barrier-friendly formula, though skin under active irritation should still be patch tested before adding it to a routine.
Does the hydration from this serum last, or fade if I stop using it?
Humectants such as sodium hyaluronate hold onto water present in the skin rather than making a lasting structural change, so the plumped feeling recedes gradually if the serum is dropped from a routine. Consistent daily use keeps the amino acids and barrier lipids working alongside it. This works as an ongoing habit rather than a step that produces a permanent result on its own.
Can I use this alongside a pore-focused or retinoid product?
The formula here is built from humectants, amino acids and barrier lipids, none of which inherently conflict with a separate pore-focused or retinoid step in the same routine. A common order is toner, this serum on damp skin, then any treatment product, followed by moisturizer. Check the other product's own label for its specific layering instructions before combining the two.
How do I confirm this 20 ml bottle is the authentic Korean-market formula?
This unit's barcode, 8809598454668, is the original Korean-market code, not a substitute applied for US retail.
- Ships from
- California
Duties are prepaid. Nothing is owed at delivery. Returns are accepted for 30 days, by mail.
Orders ship from our California warehouse, dispatched within 2 business days, and arrive in 3 to 5 days. Shipping is free on orders of $100 or more.
We split shipments free, so one out-of-stock item never holds up the rest of your order.
Where this unit came from
- 1Seoul
Bought as Korean-market stock - 2Customs
Duty paid by us before it enters the US - 3California
Ships domestically, no international leg
We stock the version of a formula that is sold in Korea, not the release a brand prepares for another market under the same name.
Every unit keeps its original barcode and batch code intact, so the unit in your hands can be checked against the brand’s own records.
Import duties are paid by us before the parcel reaches you, so nothing is owed at the door, and returns run for 30 days.
Every claim on this page traces to the unit in the box, the barcode, the batch code and the price you can read for yourself.
Payment and security
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How to use
- Use the Hyaluronic Acid 3 Serum after toner and before moisturizer, morning and evening, on skin still damp from the step before.
- Three or four drops covers the whole face. Press it in with flat palms instead of rubbing it around.
- Toner first, this second, then moisturizer over the top within a minute, while the layer underneath is still damp.
- Twice a day, every day. Do not leave it bare on the skin with nothing over it; a water layer with no cream on top gives most of that water back to the air.
Worth knowing
- This formula carries an active acid, so pairing it with another exfoliant in the same routine is worth spacing out.
Reviews
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COSRX, Korean-market original
Hyaluronic Acid Serum, 20 ml, led by Sodium Hyaluronate.
Verify your unit when it arrives
Verify your unit when it arrives
Korean-market stock with the original barcode and batch code intact, exactly as it left Korea.
COSRX verifies units itself. Find the verification page on cosrx.com and enter the batch number and expiration date printed on your unit. Read them off the package rather than from us, which is the point.
Source: COSRX FAQ
On the unit itself
- The Korean-market barcode, unaltered from the retail package.
- The manufacturer’s batch code, exactly as the maker printed it.
정품Genuine article, Korean-market stock
What professionals say
What professionals say
What skin-care professionals say about the key actives in this formula, quoted from the medical sources linked beside each.
Hyaluronic acid helps bind water to collagen, which traps water in the skin. That helps make the skin more plump and full-looking.
Samantha Stein, PA-CDermatology physician assistant, Cleveland Clinic Ceramides are part fatty acid and part amino acid and are able to be the grout that keeps the building blocks of the skin together and functioning as a barrier between the inside and outside world.
Amy Kassouf, MDDermatologist, Cleveland Clinic
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