Kose Je l'aime Deep Inner Repair Hair Mask

DESCRIPTION

What It Does: Provides nmf-type humectant moisture retention and skin conditioning.

Why It's Used: Simple, well-tolerated nmf amino acid humectant for skin conditioning formulations.

How It Works: Small methyl side chain contributes to protein hydrophobic core but as free amino acid provides direct humectant activity via amino and carboxyl groups. converted to pyruvate for cellular atp production via gluconeogenesis.

Typically Found In: Nmf moisturizers,skin conditioning products

TECHNICAL DETAILS

Primary Category: Active ingredient – amino acid

Secondary Functions: Nmf component,cellular energy

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

Free alanine is among the most abundant amino acids in the stratum corneum nmf, where it contributes to the aqueous phase hydration that keeps the stratum corneum flexible and functional.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides amino group-mediated preferential adsorption to damaged hair for targeted conditioning.

Why It's Used: Premium hair conditioning silicone – amino groups provide substantive adsorption to hair far exceeding pdms, with automatic targeting to the most damaged areas requiring conditioning.

How It Works: Amino (nh2) groups on silicone chain provide cationic character at normal ph, electrostatic adsorption to anionic hair surface. higher charge density at damaged sites increases adsorption where conditioning is most needed. si-o-si backbone provides permanent conditioning film with heat protection.

Typically Found In: Intensive conditioners,anti-frizz products,damage repair conditioners

TECHNICAL DETAILS

Primary Category: Functional ingredient – amino-functional silicone

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%–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

Amodimethicone's amino group-driven substantivity to damaged hair is dramatically greater than non-functionalized pdms. studies show amodimethicone deposits 50-200× more mass on bleach-damaged hair vs virgin hair, providing an automatic 'damage detection' conditioning system that directs the most conditioning to the hair areas that need it most.

Last Verified: Cosing database,robbins hair science,cir safety assessment

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: 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 — enzymes, receptors, structural proteins, or signaling molecules — 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: 0.01–5%

SOURCING & ETHICS

Vegan Status: No

Halal Status: Conditional

Source Notes: Contains animal-derived components (collagen...); not suitable for vegan formulations.

SKIN COMPATIBILITY

Irritancy Rating: 1

Comedogenicity Rating: 0

Sensitivity Concerns: Low sensitization potential at recommended use concentrations.

Safe for Sensitive Skin: Conditional

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-γ 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

DESCRIPTION

What It Does: Provides sulfur for keratin disulfide bonds, supports glutathione antioxidant synthesis, and directly scavenges free radicals.

Why It's Used: Hair strengthening via keratin disulfide bond support and antioxidant defense as a glutathione precursor.

How It Works: Thiol group (-sh) forms disulfide bonds (-s-s-) between adjacent keratin chains providing mechanical strength to hair and nails. glutathione synthase uses cysteine as the rate-limiting substrate for the master antioxidant glutathione.

Typically Found In: Hair strengthening treatments,keratin products,antioxidant formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – amino acid

Secondary Functions: Keratin disulfide bond,glutathione precursor

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 – 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

Hair's mechanical strength (tensile and torsional) is primarily determined by the density of disulfide crosslinks between adjacent keratin alpha-helices. chemical treatments (bleaching, perming) break these bonds; cysteine topical application may support their restoration.

Last Verified: Cosing database,cir safety assessment,keratin chemistry literature

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: 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 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

Ethanol has an established safety profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,ethanol technical literature

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: Provides nmf amino acid skin conditioning and collagen-constituent support.

Why It's Used: The collagen amino acid — glycine is the most abundant amino acid in collagen (every third residue in the triple helix is glycine) making topical glycine the most physiologically relevant collagen-support amino acid.

How It Works: Nmf component via zwitterionic water retention. collagen triple helix requires gly-x-y repeat where glycine's small size allows close packing. wound healing via fibroblast glutathione synthesis support. anti-inflammatory via glycine-gated chloride channel activation (inhibitory neuromodulator).

Typically Found In: Skin conditioning products,wound healing,nmf moisturisers

TECHNICAL DETAILS

Primary Category: Active ingredient – simplest amino acid

Secondary Functions: Skin conditioning

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 – fermentation or 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

Glycine's mandatory presence at every third position in collagen's triple helix (gly-x-y repeat) arises from its unique zero side-chain structure — only glycine is small enough to fit at the sterically restricted centre of the triple helix where the three polypeptide chains cross. no other amino acid can substitute for glycine in the collagen triple helix without disrupting the structure, making glycine irreplaceable in collagen biology.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides nmf conditioning with copper-chelating antioxidant and uv-absorbing activity from imidazole ring.

Why It's Used: Antioxidant nmf amino acid — histidine's imidazole ring provides unique copper-chelating antioxidant activity alongside nmf hydration and uv absorption not available from other nmf amino acids.

How It Works: Imidazole ring chelates cu²⁺ and fe²⁺ for antioxidant metal chelation (inhibiting fenton reaction). uv absorption at 211nm provides partial photoprotection. precursor for carnosine (with beta-alanine) for anti-glycation. nmf component via imidazole + carboxylate water binding.

Typically Found In: Antioxidant skincare,anti-aging products,nmf moisturisers

TECHNICAL DETAILS

Primary Category: Active ingredient – imidazole amino acid

Secondary Functions: Skin conditioning

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 – fermentation

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

Histidine's imidazole ring's copper chelation provides the same chemical mechanism as the pharmaceutical cuprimine (d-penicillamine) used for copper chelation therapy in wilson's disease — just with significantly lower affinity. the imidazole copper chelation prevents fenton-type radical generation from free copper ions that would otherwise catalyse hydroxyl radical production from hydrogen peroxide.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12