Hada Labo Kouji Tightening & Hydration Gel Emulsion 50Ml

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: 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: 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 endogenous-skin-identical emolliency with exceptional stability and skin compatibility.

Why It's Used: The most skin-compatible emollient – chemically identical to human sebum squalene component with outstanding tolerability across all skin types.

How It Works: Fully saturated hydrocarbon with zero oxidation sites provides exceptional stability unlike squalene's 6 double bonds. integrates into stratum corneum lipid bilayers with near-perfect biocompatibility. provides antioxidant protection to formulation via radical quenching.

Typically Found In: Facial oils,serums,non-comedogenic moisturizers,luxury body care

TECHNICAL DETAILS

Primary Category: Functional ingredient – emollient

Secondary Functions: Maximum biocompatibility,antioxidant stabilizer,non-comedogenic

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–100%

SOURCING & ETHICS

Vegan Status: Conditional – plant-derived (sugarcane, olive) preferred; shark liver-derived being phased out

Halal Status: Yes – plant-derived

Source Notes: Sustainable plant-derived squalane from sugarcane fermentation (amyris) or olive oil fractionation is preferred over shark liver-derived. chemically identical regardless of source.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

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

Squalene constitutes approximately 12-15% of human sebum – the highest proportion of any skin lipid. topical squalane (stable, hydrogenated form) replenishes this abundant endogenous skin lipid. the complete absence of oxidizable double bonds (unlike squalene's 6 double bonds) eliminates the pro-oxidant concerns of natural squalene oxidation.

Last Verified: Cosing database,huang et al. squalane review,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides the universal solvent and vehicle for water-soluble actives and the continuous phase of all o/w emulsions.

Why It's Used: The most essential cosmetic ingredient — aqua (water) is listed first on virtually all water-containing cosmetic inci labels as the highest-concentration ingredient, serving as the foundation of the global cosmetics industry.

How It Works: Acts as solvent for all water-soluble ingredients (glycols, amino acids, water-soluble actives). forms the continuous external phase of o/w emulsions (lotions, creams, serums). provides aqueous environment for enzymatic and chemical reactions between actives. ph adjustment medium.

Typically Found In: Virtually all cosmetic products — the most universal cosmetic ingredient globally

TECHNICAL DETAILS

Primary Category: Functional ingredient – water

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: Varies widely — up to 95% in some toners and serums

SOURCING & ETHICS

Vegan Status: Yes – water (deionised/purified)

Halal Status: Yes

Source Notes: Cosmetic-grade water is purified (deionised, distilled, or ro filtered) to prevent mineral content interference with formulation stability. european pharmacopoeial water (aqua purificata ph. eur.) is the quality standard for pharmaceutical and high-end cosmetic formulations.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – non-irritant

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

Water's position as the first inci ingredient on most cosmetic labels reflects the regulatory requirement to list ingredients in descending concentration order — meaning water is the most abundant ingredient in the majority of cosmetic products. the fundamental role of water as the universal cosmetic solvent and vehicle makes it simultaneously the most important cosmetic ingredient and the one that requires the most sophisticated formulation chemistry to control — every emulsifier, thickener, preservative, and ph adjuster exists primarily to manage water's interaction with other ingredients in formulation.

Last Verified: Cosing database,eu cosmetics regulation 1223/2009 inci requirements,ph. eur. aqua purificata monograph

Primary Sources: 2026-03-12