COSRX Official
Master Patch X-Large
Master Patch X-Large
COSRX Official
master-patch-x-large
Spot Patches
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Highlights
WHAT IS IT?
Large hydrocolloid acne patch with 6 ingredients
FEATURES
Spot treatment to solve unplanned breakouts.
BEST FOR
Oily skin, acne-prone skin
CHECKS
Free of sulfates, parabens
Who Is It For?
Adults (18+) Both Men And WomenWhat Does It Help With?
Acne Blemishes Oily PoresBudget
AffordableHow To Use
Which routine should it be used in?
Instructions:
Key Information
What COSRX Official Says
Product Description:
The Original Acne Patch, Just Bigger. Comfortable hydrocolloid patch to solve your large area of oily pores. Use as a safer alternative to pore strips.
About the Brand:
Ingredients Overview
Ingredients List
Cellulose Gum, Hydrogenated Poly(C6-20 Olefin), Pentaerythrityl Tetra-di-t-butyl Hydroxyhydrocinnamate, Polyisobutene, Styrene/Isoprene Copolymer, Niacinamide
Key Ingredients
Niacinamide
Ingredients Details
Cellulose Gum
Common Name(s): Cellulose gum,cosmetic active,functional ingredient
CAS Number: N/a
DESCRIPTION
What It Does: Delivers characteristic cosmetic function at recommended use concentration.
Why It's Used: Selected for functional contribution and formulation compatibility supported by cosmetic science and regulatory safety data.
How It Works: Works through the mechanism of its molecular class โ physicochemical or biological interaction with skin proteins, lipids, or receptors as documented in peer-reviewed cosmetic literature.
Typically Found In: Skin care formulations
TECHNICAL DETAILS
Primary Category: Active ingredient โ cosmetic active
Secondary Functions: Skin conditioning
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.1%โ10%
SOURCING & ETHICS
Vegan Status: Conditional
Halal Status: Yes
Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.
SKIN COMPATIBILITY
Irritancy Rating: 1/5 โ very low
Comedogenicity Rating: 0/5 โ non-comedogenic
Sensitivity Concerns: Well-tolerated by most skin types.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Good safety profile at recommended concentrations. ewg score: 1โ2.
Works Well With: Standard skincare actives
Avoid Combining With: No known significant incompatibilities
SCIENTIFIC NOTE
Cellulose gum has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.
Last Verified: Cosing database,cellulose gum technical literature
Primary Sources: 2026-03-12
Hydrogenated Poly(c6-20 Olefin)
Common Name(s): Hydrogenated poly(c6-20 olefin)
DESCRIPTION
What It Does: Delivers targeted skin-conditioning or bioactive benefits through a specific mechanism of action suited to the formulation's intended purpose.
Why It's Used: Specialty actives address specific skin concerns through targeted molecular mechanisms, providing efficacy beyond what base formulation ingredients alone can achieve.
How It Works: The bioactive compound interacts with specific molecular targets in skin cells or the extracellular matrix โ enzymes, receptors, structural proteins, or signaling molecules โ triggering beneficial biological responses.
Typically Found In: Serums,treatments,moisturizers,specialty products
TECHNICAL DETAILS
Primary Category: Specialty actives
Secondary Functions: Skin-conditioning,anti-aging
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.01โ5%
SOURCING & ETHICS
Vegan Status: Yes
Halal Status: Yes
Source Notes: Specialty active ingredient; check individual sourcing for vegan status.
SKIN COMPATIBILITY
Irritancy Rating: 1
Comedogenicity Rating: 0
Sensitivity Concerns: Low sensitization potential at recommended use concentrations.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Well-characterized cosmetic ingredient with established safety profile. generally non-irritating at typical use concentrations. suitable for leave-on and rinse-off cosmetics.
Works Well With: Niacinamide,hyaluronic acid,vitamin c,peptides
Avoid Combining With: Incompatible with oxidizing agents; check ph stability
SCIENTIFIC NOTE
Specialty actives typically work through enzyme inhibition (e.g., tyrosinase inhibition for brightening, mmp inhibition for anti-aging), receptor activation (e.g., retinoid receptors, ppar-ฮณ for barrier genes), or transcription factor modulation (e.g., nrf2 for antioxidant gene upregulation). structure-activity relationships determine potency and selectivity.
Last Verified: Cosing eu database; pcpc cosmetic ingredient safety reviews; ingredient-specific safety and efficacy literature
Primary Sources: 2025-01-15
Niacinamide
Common Name(s): Vitamin b3,nicotinamide,pyridine-3-carboxamide
CAS Number: 98-92-0
DESCRIPTION
What It Does: Niacinamide strengthens the skin barrier, reduces visible pore size, regulates sebum production, fades dark spots, and improves skin texture and tone.
Why It's Used: It is used because it addresses multiple skin concerns at once without irritation, making it suitable for all skin types. it is stable in formulations and pairs well with most other actives.
How It Works: Niacinamide inhibits the transfer of melanosomes (pigment packets) to skin cells, reducing hyperpigmentation. it also stimulates ceramide synthesis to strengthen the skin barrier and reduces inflammation by modulating cytokine activity.
Typically Found In: Serums,moisturizers,toners,cleansers,eye creams,sunscreens,primers
TECHNICAL DETAILS
Primary Category: Active ingredient โ vitamin
Secondary Functions: Barrier repair,brightening,anti-inflammatory
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 2%โ10% (typical: 5%; higher concentrations may cause flushing in some individuals)
SOURCING & ETHICS
Vegan Status: Yes โ synthetically produced
Halal Status: Yes โ synthetic origin
Source Notes: Commercially produced via synthesis from nicotinic acid or 3-cyanopyridine. no animal-derived sources used in cosmetic-grade niacinamide.
SKIN COMPATIBILITY
Irritancy Rating: 1/5 โ very low; concentrations above 10% may cause temporary flushing in sensitive individuals
Comedogenicity Rating: 0/5 โ non-comedogenic
Sensitivity Concerns: At concentrations >10%, some users experience niacin flush (transient redness/tingling). generally very well-tolerated.
Safe for Sensitive Skin: Yes โ one of the best-tolerated actives for sensitive skin
SAFETY & COMPATIBILITY
Safety Profile: Extensively studied and considered very safe. ewg hazard score: 1. no significant systemic toxicity concerns at topical concentrations.
Works Well With: Retinol,peptides,ahas/bhas,hyaluronic acid,ceramides,zinc,vitamin c,spf
Avoid Combining With: High concentrations of vitamin c (ascorbic acid) may theoretically convert to niacin โ use at different times if using pure l-ascorbic acid above 15%
SCIENTIFIC NOTE
Niacinamide is a precursor to nad+ and nadp+, coenzymes vital to cellular energy metabolism. its benefits for dna repair and mitochondrial function make it a key ingredient in anti-aging strategies.
Last Verified: Cosing database,cir safety assessment,ewg skin deep,pubmed clinical studies
Primary Sources: 2026-03-12
Pentaerythrityl Tetra-di-t-butyl Hydroxyhydrocinnamate
Common Name(s): Pentaerythrityl tetra-di-t-butyl hydroxyhydrocinnamate
DESCRIPTION
What It Does: Absorbs or reflects uv radiation, preventing uv-induced dna damage, photo-oxidative stress, and premature skin aging.
Why It's Used: Uv filters are the active ingredients in sun protection โ without them, formulations cannot make spf claims or prevent solar-induced skin damage.
How It Works: The uv-absorbing chromophore undergoes photoexcitation by uv photons, then dissipates the absorbed energy through thermal relaxation (chemical filters) or photon scattering/reflection (physical filters), preventing photon penetration to skin cells.
Typically Found In: Sunscreens,moisturizers with spf,foundations with spf
TECHNICAL DETAILS
Primary Category: Uv filters
Secondary Functions: Skin-protecting
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.5โ25% (within regulatory limits)
SOURCING & ETHICS
Vegan Status: Yes
Halal Status: Yes
Source Notes: Synthetic uv filter; no animal components.
SKIN COMPATIBILITY
Irritancy Rating: 1
Comedogenicity Rating: 0
Sensitivity Concerns: Contact allergy to uv filters occurs in approximately 1โ3% of the general population; patch testing recommended for those with known photosensitivity.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Regulatory approval required per market (eu annex vi, fda otc monograph, etc.). generally non-irritating at approved concentrations.
Works Well With: Other uv filters,antioxidants,emollients
Avoid Combining With: Incompatible filter combinations (photodegradation); check regulatory approvals per region
SCIENTIFIC NOTE
Uv filters operate through two mechanisms: organic/chemical filters absorb uv photons through electronic excitation (ฯโฯ* transitions in conjugated systems), then dissipate energy via thermal relaxation; inorganic/physical filters (tio2, zno) scatter and reflect photons through mie scattering (particle size 50โ300 nm) and band gap absorption. spf is measured in vivo (iso 24444) as the ratio of minimal erythema doses with and without sunscreen.
Last Verified: Cosing eu database; pcpc cosmetic ingredient safety reviews; eu cosmetics regulation annex vi; iso 24444 (in vivo spf testing)
Primary Sources: 2025-01-15