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COSRX · Masks

Master Patch Intensive

$12·Leave-on
80
Low concern

Why this score

Concern47 / 55
  • Tea Tree Oil: watch if sensitive

How much genuine, cited concern the ingredients carry, weighted by how much of each is likely present and whether the product stays on or rinses off.

Transparency20 / 20
  • No hidden fragrance blend.

Whether the full ingredient list, and any fragrance, are actually disclosed.

Formulation restraint13 / 25
  • 2 known irritant or fragrance-allergen ingredients: Salicylic Acid, Tea Tree Oil.

Needless irritant or allergen load for the product type. A clean, purposeful formula scores well without any "free-from" theater.

Scored by PlainBody Editorial against the PlainScore method · Label checked July 2026

What’s inside

Cellulose GumGenerally safe

A plant-based thickener derived from cellulose that creates smooth, gel-like textures in formulas. One of the most studied and best-tolerated thickeners in cosmetics, used in shampoos, face masks, and leave-on products for decades.

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Hydrogenated Poly(C6-14 Olefin)Generally safe

A saturated hydrocarbon emollient that softens skin and gives products a smooth glide. Its saturated structure makes it stable and well tolerated. It is inert and carries a low sensitization risk at typical cosmetic use levels.

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PolyisobuteneGenerally safe

A synthetic film-forming emollient that provides a protective, flexible layer on skin. Not absorbed and well tolerated with no documented safety issues in cosmetic use.

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Salicylic AcidGenerally safe

A beta hydroxy acid used to smooth texture and clear pores. Safe at cosmetic levels; can be mildly irritating if overused.

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Tea Tree OilWatch if sensitive

Tea tree oil is used for its antimicrobial reputation in blemish-focused products, but it is a genuine, well-documented contact sensitizer, and its allergy potential rises sharply once the oil has oxidized from air exposure. Fresh, well-preserved, low-concentration formulations are much lower risk than old or improperly stored oil.

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Lower-concern alternatives

Same category, higher PlainScore.

Cosmetic information for general education, not medical advice. Concern ratings are evidence-graded and cited on each ingredient page. See how we score.