Kerastase Specifique Hydra-Apaisant Hair Mask For Sensitive Scalp & Hair, Rebalances & Soothes

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: 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-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 anti-glycation and anti-carbonylation activity protecting collagen from glycation-induced crosslinking.

Why It's Used: Natural anti-age dipeptide targeting glycation — complementary to antioxidant-only anti-aging strategies with documented collagen protection.

How It Works: Histidine imidazole chelates cu²⁺ for antioxidant metal chelation. beta-alanine traps reactive carbonyl species (glycating aldehydes). quenches 4-hydroxynonenal (hne) protein carbonylation. anti-glycation via competing with lysine residues.

Typically Found In: Anti-aging serums,anti-glycation products,longevity skincare

TECHNICAL DETAILS

Primary Category: Active ingredient – antioxidant

Secondary Functions: Free radical scavenging,anti-aging

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 – synthetic

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: Non-irritating; well-tolerated.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

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

Works Well With: Vitamin c,vitamin e,ferulic acid,spf,other antioxidants

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Carnosine's anti-glycation mechanism is sacrificial carbonyl trapping: reactive carbonyl species (methylglyoxal, glyoxal) that would normally glycate collagen lysines are instead captured by carnosine's free amino groups — carnosine acts as a sacrificial protector for collagen, being consumed in the process of preventing more damaging collagen glycation.

Last Verified: Cosing database,guiotto et al. carnosine anti-glycation 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: Activates trpm8 cold thermoreceptors for intense cooling sensation and analgesic activity.

Why It's Used: The most potent cosmetic cooling agent – direct trpm8 agonist providing cooling sensation without actual temperature reduction for refreshing and analgesic formulations.

How It Works: Potent trpm8 (menthol receptor/cold thermosensor) agonist – activation at room temperature mimics cold sensation without actual cooling. anti-pruritic via trpm8 activation competing with itch c-fiber signaling. antimicrobial via membrane disruption.

Typically Found In: Cooling products,scalp treatments,oral care,pain relief,foot care,after-sun

TECHNICAL DETAILS

Primary Category: Active ingredient – cooling sensory terpenoid

Secondary Functions: Redness reduction,anti-inflammatory,calming

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 – from mentha piperita or synthetic

Halal Status: Yes

Source Notes: Plant-derived extract or synthetic.

SKIN COMPATIBILITY

Irritancy Rating: 2/5 – low to moderate; potential sensitizer

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; ideal for reactive and sensitive skin.

Safe for Sensitive Skin: Avoid near eyes. use with caution at concentrations above 1% for sensitive skin.

SAFETY & COMPATIBILITY

Safety Profile: Eu max 4.5% (leave-on); regulations vary by application site. avoid on infants' face.

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

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Menthol's exceptional cooling potency stems from its ec50 for trpm8 activation of approximately 10μm (vs camphor's ec50 of ~5mm – 500× lower potency). this 500× potency advantage explains why even tiny concentrations of menthol provide intense cooling, while much higher concentrations of camphor are required for equivalent sensation.

Last Verified: Cosing database,mckemy et al. menthol trpm8 discovery,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Activates trpm8 cold thermoreceptors for intense cooling sensation and analgesic activity.

Why It's Used: The most potent cosmetic cooling agent – direct trpm8 agonist providing cooling sensation without actual temperature reduction for refreshing and analgesic formulations.

How It Works: Potent trpm8 (menthol receptor/cold thermosensor) agonist – activation at room temperature mimics cold sensation without actual cooling. anti-pruritic via trpm8 activation competing with itch c-fiber signaling. antimicrobial via membrane disruption.

Typically Found In: Cooling products,scalp treatments,oral care,pain relief,foot care,after-sun

TECHNICAL DETAILS

Primary Category: Active ingredient – cooling sensory terpenoid

Secondary Functions: Redness reduction,anti-inflammatory,calming

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 – from mentha piperita or synthetic

Halal Status: Yes

Source Notes: Plant-derived extract or synthetic.

SKIN COMPATIBILITY

Irritancy Rating: 2/5 – low to moderate; potential sensitizer

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; ideal for reactive and sensitive skin.

Safe for Sensitive Skin: Avoid near eyes. use with caution at concentrations above 1% for sensitive skin.

SAFETY & COMPATIBILITY

Safety Profile: Eu max 4.5% (leave-on); regulations vary by application site. avoid on infants' face.

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

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Menthol's exceptional cooling potency stems from its ec50 for trpm8 activation of approximately 10μm (vs camphor's ec50 of ~5mm – 500× lower potency). this 500× potency advantage explains why even tiny concentrations of menthol provide intense cooling, while much higher concentrations of camphor are required for equivalent sensation.

Last Verified: Cosing database,mckemy et al. menthol trpm8 discovery,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Prevents microbial contamination and spoilage in cosmetic formulations.

Why It's Used: The benchmark cosmetic preservative – eu-permitted up to 1%, effective against virtually all cosmetically relevant microorganisms, and excellent tolerability.

How It Works: Phenol ring provides broad antimicrobial activity via disruption of bacterial and fungal cell membranes and inhibition of enzymatic activity. effective against gram-positive and gram-negative bacteria, yeasts (candida), and molds (aspergillus). activity ph range: 3-9.

Typically Found In: All cosmetic formulations as primary preservative

TECHNICAL DETAILS

Primary Category: Functional ingredient – broad-spectrum preservative

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%–1% (eu max 1%)

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: Eu cosmetics regulation max 1%. sccs assessed as safe at ≤1%. avoid use around eyes in baby products per some country regulations. ewg score: 4.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Phenoxyethanol's widespread adoption as the primary cosmetic preservative followed the phaseout of parabens from many formulations in the 2000s-2010s. despite having a comparable or better safety profile to parabens, it is often cited in 'free-from' formulations – a consumer perception issue rather than a scientific safety concern.

Last Verified: Cosing database,sccs opinion on phenoxyethanol,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides documented functional activity from quaternium-87.

Why It's Used: Quaternium-87 contributes established cosmetic function from its characteristic chemical structure and physicochemical properties.

How It Works: Chemical structure provides documented cosmetic function. safety: established in cosmetic science literature and regulatory review. use: standard cosmetic concentrations.

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

Quaternium-87 provides documented cosmetic activity through its characteristic mechanism. established in cosmetic science literature with regulatory review supporting safety at standard formulation concentrations.

Last Verified: Cosing database,quaternium-87 technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Delivers characteristic cosmetic function — skin conditioning, antioxidant protection, active biological benefit, or formulation 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

Rhamnose has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,rhamnose technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Delivers characteristic cosmetic function — skin conditioning, antioxidant protection, active biological benefit, or formulation 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

Rhamnose has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,rhamnose technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Tocopherol neutralizes free radicals that damage skin cells, protects cell membranes from lipid peroxidation, moisturizes, and helps maintain a healthy skin barrier.

Why It's Used: It is used as both a skin-active antioxidant and a formulation stabilizer (preventing oxidation of other ingredients). it has decades of safety and efficacy evidence and works synergistically with vitamin c.

How It Works: As a chain-breaking antioxidant, tocopherol donates hydrogen atoms to interrupt lipid peroxidation chain reactions. it is regenerated by vitamin c (ascorbic acid) in the vitamins c+e antioxidant cycle, creating a more durable antioxidant defense.

Typically Found In: Moisturizers,serums,oils,sunscreens,eye creams,lip balms,antioxidant formulations,haircare products

TECHNICAL DETAILS

Primary Category: Active ingredient – antioxidant/vitamin e

Secondary Functions: Emollient,formulation stabilizer,barrier support

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–1% (typical: 0.1–0.5% as active; higher as formulation antioxidant)

SOURCING & ETHICS

Vegan Status: Yes – plant-derived (soybean, sunflower, wheat germ oil) or synthetic

Halal Status: Yes – plant-derived or synthetic

Source Notes: Natural d-alpha-tocopherol is derived from plant oils and is more bioactive. synthetic dl-alpha-tocopherol is less expensive. tocopherol acetate (tocopheryl acetate) is the more stable ester form.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low; rare contact sensitivity reported

Comedogenicity Rating: 2/5 – mildly comedogenic at higher concentrations; formulation-dependent

Sensitivity Concerns: A small percentage of people report contact sensitization to tocopherol, particularly with leave-on products. comedogenicity risk is higher in oil-heavy formulations.

Safe for Sensitive Skin: Generally yes; perform patch test if history of vitamin e sensitivity

SAFETY & COMPATIBILITY

Safety Profile: Very safe; widely used. ewg hazard score: 2–3 (depending on concentration). no significant systemic concerns from topical use.

Works Well With: Ascorbic acid (vitamin c) – synergistic antioxidant pair,ferulic acid – stabilizes and boosts both c and e,ceramides,spf,retinol

Avoid Combining With: Very high concentrations of benzoyl peroxide may oxidize tocopherol; potential comedogenicity concerns in acne-prone skin when in heavy oil bases

SCIENTIFIC NOTE

The combination of vitamin c, vitamin e, and ferulic acid (the 'ce ferulic' formulation) provides fourfold photoprotection against uv-induced free radical damage – a synergy documented in landmark research by pinnell et al.

Last Verified: Cosing database,cir safety assessment,pinnell et al. (2005) journal of investigative dermatology,efsa panel on food additives

Primary Sources: 2026-03-12