COSRX
Master Patch Basic
The original hydrocolloid blemish patch: a clean four-entry material list that absorbs fluid and shields the spot while it settles.
No reviews yet- Ships from our California warehouse
- Duties prepaid
- Suited to
- NormalCombinationDry
- Helps with
- Shoppers who want the full Master Patch Basic assembled as one purchase instead of sourcing each item on its ownConsistent use across every piece in the set, since a multi-step routine compounds over weeks of use rather than showing a result from one application
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One email, the moment this exact unit is back in stock. Not a newsletter and not a sequence, and your address comes off the list the second it is sent.
- Duties prepaid
- 30-day returns
- Free US shipping on orders of $100 or more
- Dispatched within 2 business days
How it works
A hydrocolloid patch is a dressing: it covers one spot, takes up what the spot gives off, and keeps fingers and fabric away from it. This is the basic patch in COSRX's Master Patch range, the plain version with nothing worked into the material. It goes on last, on clean dry skin, because nothing sticks over a serum or a cream that has not absorbed. The middle turns white or cloudy while it is on, which is the fluid it has drawn up. One patch per spot, overnight, then a fresh one if the spot is still there.
Key benefits
- Hydrocolloid absorbs fluid from the spot and turns visibly white as it works
- Covering the spot keeps fingers off it, which is half the battle
- A short material list with nothing to sensitize the skin around the spot
- Thin cut edges sit flat enough for day or night wear
Key actives
Cellulose Gum
the absorbent core of the hydrocolloid dressing
COSRX Master Patch Basic
What does the Master Patch Basic actually do?
This is COSRX's simplest hydrocolloid patch, a four-ingredient material list: cellulose gum, hydrogenated poly(C6-20 olefin), polyisobutene and styrene/isoprene copolymer. Cellulose gum is the absorbent core that pulls fluid from a blemish, while the other three form the flexible adhesive film around it. There's no named active ingredient added on top, just the dressing itself. Thirty-six patches ship per box for spot-by-spot use.
Is this a safe pick for sensitive or reactive skin?
Fragrance, essential oil, denatured alcohol, silicone, parabens, sulfate surfactants, mineral oil and added colourant are all absent from this four-entry ingredient list. With only cellulose gum and three adhesive-film ingredients present, there is very little in the formula beyond the dressing material itself. That short a list is one of the more straightforward options for skin that reacts to actives, though any material touching skin, including an adhesive film, can still irritate in individual cases.
Will this patch make a blemish disappear by morning?
The patch works by absorbing fluid out of a spot into the cellulose gum layer, which is why the center turns visibly white or cloudy as it fills. That's evidence the dressing is doing its job of drawing fluid and shielding the area, not evidence the blemish itself is gone underneath. Replacing a saturated patch, rather than expecting one overnight application to finish the process, is the realistic way to use it.
Can I use this with a spot treatment or retinoid step?
No ingredient on this four-ingredient list overlaps with an active spot treatment or a retinoid, since the patch is purely an absorbent dressing. Applying a leave-on treatment to clean, dry skin first and letting it fully absorb before pressing the patch on keeps the two from sliding around on wet skin. The patch then sits over that spot rather than under it.
How do I check that my Master Patch Basic is the authentic formula?
COSRX also verifies units directly: the batch number and expiration date on your box can be entered on the verification page at cosrx.com. Reading those two codes off your own packaging, rather than trusting a listing's word for it, is the actual verification.
- 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
We accept
How to use
- Press one Master Patch Basic onto clean, dry skin at the end of the evening routine.
- Choose the size that covers the spot with a small margin, then press from the middle outward until the edges lie flat.
- Nothing goes over it, and it holds best on bare skin, so let every leave-on layer absorb first.
- One patch per spot per night. Do not press one onto damp skin or over a cream; it will lift within the hour.
Reviews
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COSRX, Korean-market original
Hydrocolloid blemish patches, 36 ea, the original fit.
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 skin care, quoted from the medical sources linked beside each.
Your skin barrier is basically your outer layer of the skin.
Melissa Piliang, MDDermatologist, Cleveland Clinic Pretty much every step of a Korean skin care routine is going to have some component of hydration.
Alok Vij, MDDermatologist, Cleveland Clinic
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