COSRX Ultimate Nourishing Rice Overnight Spa Mask

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 — 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 – 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%–10%

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 – very low

Comedogenicity Rating: 0/5 – 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: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

1-2-hexanediol has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,1-2-hexanediol technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Soothes irritation, accelerates wound healing, promotes skin cell renewal, and provides mild keratolytic exfoliation.

Why It's Used: Gold standard multi-function soothing active – one of the most widely used cosmetic ingredients across all product types for its exceptional tolerability and clinically proven multi-action skin conditioning.

How It Works: Promotes keratinocyte proliferation and fibroblast migration for wound healing. mild keratolytic activity by disrupting corneocyte binding. anti-irritant via direct protein binding and anti-inflammatory cytokine reduction. humectant activity via hydroxyl groups.

Typically Found In: Post-procedure products,sensitive skin formulas,wound care,anti-acne treatments,baby products

TECHNICAL DETAILS

Primary Category: Active ingredient – soothing / anti-inflammatory

Secondary Functions: Wound healing,keratolytic,anti-irritant

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–2%

SOURCING & ETHICS

Vegan Status: Yes – synthetic or comfrey-derived

Halal Status: Yes

Source Notes: Plant-derived extract or synthetic.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Exceptionally well-tolerated; suitable for all skin types including baby and compromised skin.

Safe for Sensitive Skin: Yes – particularly recommended for sensitive skin

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Ceramides,panthenol,allantoin,hyaluronic acid,centella asiatica

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Allantoin's keratinocyte proliferation stimulation occurs via receptor-mediated signaling (possibly machr activation) rather than non-specific irritation-driven proliferation, making it a true wound-healing stimulant rather than a pro-inflammatory proliferative signal.

Last Verified: Cosing database,cir safety assessment,araújo et al. allantoin review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Conditions skin, attracts moisture, supports wound healing, and improves microcirculation via no synthesis.

Why It's Used: Multi-functional amino acid for skin hydration, conditioning, and wound healing in peptide and nmf formulations.

How It Works: Guanidinium group binds water (humectant). substrate for nitric oxide synthase (enos) producing nitric oxide that vasodilates capillaries improving skin nutrition. stimulates fibroblast proliferation for wound healing.

Typically Found In: Anti-aging serums,wound healing products,nmf moisturizers,scalp treatments

TECHNICAL DETAILS

Primary Category: Active ingredient – amino acid

Secondary Functions: Wound healing,microcirculation,nmf component

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.5%–5%

SOURCING & ETHICS

Vegan Status: Yes – plant-derived or synthetic

Halal Status: Yes

Source Notes: Fermentation-derived or synthetic. natural skin component.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; endogenous skin molecule.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. natural skin nmf component. ewg score: 1.

Works Well With: Hyaluronic acid,ceramides,peptides,other amino acids

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Arginine is a conditionally essential amino acid in wound healing where local demand exceeds synthesis capacity. topical arginine provides the nos substrate locally for no-mediated vasodilation and immune cell function in healing tissue.

Last Verified: Cosing database,cir safety assessment,witte & barbul arginine wound healing review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides osmoprotective humectant conditioning with anti-irritant and mild foam-boosting activity.

Why It's Used: Natural-origin multifunctional osmolyte from sugar beet providing hydration, anti-irritancy, and conditioning in virtually every cosmetic category.

How It Works: Quaternary ammonium betaine provides zwitterionic character for water binding via ionic hydration. osmoprotective function at 100–500mm as compatible solute protecting cells from osmotic stress. reduces surfactant irritation by competing with sls for protein binding sites. mild foam enhancement.

Typically Found In: Virtually all categories — moisturisers, shampoos, cleansers

TECHNICAL DETAILS

Primary Category: Functional ingredient – humectant

Secondary Functions: Tewl reduction,skin plumping

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.5%–10%

SOURCING & ETHICS

Vegan Status: Yes – from beta vulgaris (sugar beet) molasses

Halal Status: Yes

Source Notes: Synthetic or naturally derived. excellent aqueous solubility.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; suitable for all skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Ceramides,emollients,occlusives,glycerin,hyaluronic acid

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Betaine's anti-irritant mechanism for surfactant systems involves competitive protein protection: betaine at high concentrations preferentially interacts with skin proteins, occupying binding sites that would otherwise be occupied by surfactant molecules causing protein denaturation. this competition reduces available protein binding for irritating surfactants, explaining betaine's well-documented ability to reduce sls irritation when co-formulated.

Last Verified: Cosing database,craig betaine osmoprotective review,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides transparent gel textures and thickening at very low concentrations via ph-responsive swelling.

Why It's Used: The most widely used gel thickener – provides crystal-clear, stable gels at concentrations as low as 0.1-0.5% with ph-controlled viscosity.

How It Works: Highly crosslinked polyacrylic acid remains tightly coiled at acidic ph. neutralization with naoh or triethanolamine ionizes carboxylic groups causing electrostatic repulsion that unfolds and swells the polymer coils, dramatically increasing viscosity. concentration-dependent thickening.

Typically Found In: Gels,serums,emulsions,sunscreens

TECHNICAL DETAILS

Primary Category: Functional ingredient – polyacrylic acid thickener

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%–2%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – 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: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Carbomer's ph-responsive swelling mechanism provides an elegant formulation control tool: a neutralized gel can be liquefied by ph reduction (adding acid) and re-thickened by reneutralization. this reversible rheology control allows two-phase products that mix on application without the need for mechanical emulsification.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides silicone-characteristic silky feel and skin protection with adjustable viscosity.

Why It's Used: The benchmark cosmetic silicone – sets the gold standard for silky application feel, spreadability, and skin protection in virtually all skin care categories.

How It Works: Polydimethylsiloxane chain flexibility provides extremely low surface tension and high spreadability. inert si-o backbone provides chemical stability and excellent skin tolerance. occlusive film formation reduces tewl. higher viscosity grades provide more intense conditioning.

Typically Found In: Moisturizers,foundations,primers,sunscreens – nearly universal

TECHNICAL DETAILS

Primary Category: Functional ingredient – polydimethylsiloxane

Secondary Functions: Barrier sealing,softening

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–30%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Plant-derived, synthetic or animal-derived. verify source.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 1/5 – low; formulation-dependent

Sensitivity Concerns: Non-irritating.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Humectants,ceramides,actives as carrier

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Dimethicone's exceptional silky feel arises from its very low intermolecular attractive forces (weak van der waals forces due to non-polar methyl groups) that allow silicone chains to slide freely over skin. the coefficient of kinetic friction for pdms against skin (~0.04) is among the lowest of any cosmetic material – explaining why even small amounts transform product feel.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides antimicrobial skin conditioning with deodorant activity and preservation system enhancement.

Why It's Used: Multifunctional clean beauty preservation active — ethylhexylglycerin provides antimicrobial, deodorant, and skin conditioning in a single ingredient accepted in most natural cosmetic certification schemes.

How It Works: Glycerol ether provides antimicrobial via bacterial membrane phospholipid disruption. deodorant activity via reduction of underarm lipase enzyme activity (similar mechanism to triethyl citrate). skin conditioning from glycerol humectant component. synergistic with phenoxyethanol and diols.

Typically Found In: Natural preservation systems,deodorants,skin conditioning products

TECHNICAL DETAILS

Primary Category: Functional ingredient – antimicrobial glycerol ether

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%–0.5%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – 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: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Ethylhexylglycerin's deodorant mechanism is pharmacologically identical to triethyl citrate: both inhibit skin surface microbial lipase enzymes that convert odourless triglycerides to odorous free fatty acids. the glycerol ether structure of ethylhexylglycerin, combined with the 2-ethylhexyl chain, provides lipase inhibition similar to ester-based lipase inhibitors from a different chemical class.

Last Verified: Cosing database,schülke sensiva sc 10 technical data,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Glycerin pulls water from the environment and deeper skin layers into the outer skin layer (epidermis), boosting moisture levels and keeping skin soft, smooth, and plump.

Why It's Used: It is used in virtually every moisturizer, serum, and cleanser because it is highly effective at hydrating skin, is well-tolerated by all skin types, and enhances the texture and spreadability of formulations.

How It Works: As a humectant, glycerin forms hydrogen bonds with water molecules, trapping them in the skin. it also reinforces the skin barrier by integrating into lipid structures between skin cells.

Typically Found In: Moisturizers,serums,cleansers,toners,sheet masks,sunscreens,body lotions,shampoos,conditioners

TECHNICAL DETAILS

Primary Category: Humectant

Secondary Functions: Skin barrier support,emollient,solvent

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–30% (typical: 3–10%)

SOURCING & ETHICS

Vegan Status: Yes – plant-derived (coconut, soy, palm) or synthetic

Halal Status: Yes – when plant-derived or synthetic; verify source with supplier

Source Notes: Derived from plant oils via hydrolysis or saponification; synthetic versions also available. palm-derived glycerin carries sustainability concerns.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low; non-irritating at all standard concentrations

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Extremely rare allergic reactions; generally safe for all skin types including sensitive and baby skin

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Widely recognized as safe. ewg hazard score: 1. no significant concerns for irritation, sensitization, or toxicity at typical concentrations (up to 50%).

Works Well With: Hyaluronic acid,ceramides,niacinamide,panthenol,urea,peptides,retinol,ahas/bhas

Avoid Combining With: No known incompatibilities at standard concentrations

SCIENTIFIC NOTE

Glycerin is an endogenous skin component found naturally in the stratum corneum. aquaporin-3 channels in keratinocytes facilitate glycerin transport, making it integral to natural skin hydration pathways.

Last Verified: Cosing database,cir safety assessment,ewg skin deep,inci decoder

Primary Sources: 2026-03-12

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 – 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%–10% (typical: 5%; higher concentrations may cause flushing in some individuals)

SOURCING & ETHICS

Vegan Status: Yes – synthetically produced

Halal Status: Yes – 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 – very low; concentrations above 10% may cause temporary flushing in sensitive individuals

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: At concentrations >10%, some users experience niacin flush (transient redness/tingling). generally very well-tolerated.

Safe for Sensitive Skin: Yes – 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 – 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