L'Oreal Professionnel Serioxyl Advanced Density Activator, Leave-In Serum

DESCRIPTION

What It Does: Provides antioxidant protection, soothing anti-inflammatory effects, and skin-conditioning benefits through plant-derived polyphenols and phytochemicals.

Why It's Used: Plant extracts concentrate bioactive phytochemicals evolved for environmental protection — uv, microbial, and oxidative stressors — that translate to skin benefits.

How It Works: Polyphenols (flavonoids, phenolic acids) inhibit nf-κb-mediated inflammatory signaling, scavenge reactive oxygen species through electron donation, and chelate pro-oxidant metal ions to reduce oxidative skin damage.

Typically Found In: Serums,toners,moisturizers,masks,essences

TECHNICAL DETAILS

Primary Category: Botanical extracts

Secondary Functions: Antioxidant,anti-inflammatory

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: Yes

Halal Status: Yes

Source Notes: Plant-derived extract; no animal components.

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,ceramides

Avoid Combining With: Strong oxidizing agents

SCIENTIFIC NOTE

Plant secondary metabolites (flavonoids, terpenes, phenolic acids) are biosynthesized as defense compounds against uv, herbivores, and pathogens. their anti-inflammatory activity typically derives from competitive inhibition of cox-2 and 5-lox enzymes (ic50 1–50 µm), while antioxidant activity involves single electron transfer (set) and hydrogen atom transfer (hat) mechanisms with structure-dependent rate constants.

Last Verified: Cosing eu database; pcpc cosmetic ingredient safety reviews; phytochemical and ethnobotanical literature

Primary Sources: 2025-01-15

DESCRIPTION

What It Does: Provides soft, lasting rose-floral fragrance note.

Why It's Used: Essential rose fragrance monoterpene for lasting smooth floral notes in high-quality perfumery and cosmetic fragrances.

How It Works: Allylic alcohol monoterpene provides fixative property in fragrance blends. good skin substantivity for lasting scent. softer, rounder rose note vs geraniol's fresher character. natural in rose otto at 18-34%.

Typically Found In: Rose perfumes,floral fragrances,luxury skincare

TECHNICAL DETAILS

Primary Category: Fragrance component – monoterpene alcohol

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.001%–1%

SOURCING & ETHICS

Vegan Status: Yes – from rose, geranium, citronella oils

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: declared fragrance allergen. ifra guidelines apply.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Citronellol's r-enantiomer (natural) vs s-enantiomer (synthetic) provide meaningfully different scent character – a remarkable demonstration of chiral scent discrimination by olfactory receptors. the (r) form provides the characteristic rose note while the (s) form has a distinctly different, less pleasant character. this enantiomeric scent difference means that the biological handedness of naturally-sourced vs racemic synthetic citronellol produces perceptibly different fragrance quality.

Last Verified: Cosing database,ifra standards

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: 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: 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 fresh rose-geranium floral scent with antimicrobial activity.

Why It's Used: The rose fragrance terpene – geraniol defines the fresh, sweet rose-geranium note found in more than 60 essential oils and is essential for recreating natural floral fragrance profiles.

How It Works: Monoterpene alcohol inhibits bacterial membrane integrity for antimicrobial activity. activates trpv1 for anti-nociception. inhibits nf-kb for anti-inflammatory activity. antioxidant via allylic radical scavenging.

Typically Found In: Rose-scented products,floral fragrances,natural cosmetics

TECHNICAL DETAILS

Primary Category: Fragrance component – acyclic monoterpene alcohol

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.001%–1%

SOURCING & ETHICS

Vegan Status: Yes – from rose, geranium, palmarosa oils

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: declared fragrance allergen. ifra guidelines apply.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Geraniol's isomers (geraniol, nerol, citronellol) provide subtly different scent characters despite identical molecular formulae (c10h18o): geraniol provides the sweet, fresh rose note while its z-isomer nerol has a more delicate, neroli-like character. these isomeric scent differences arise from different spatial presentation of the hydroxyl and double bond groups to the olfactory receptor – demonstrating the extraordinary structural sensitivity of olfactory perception.

Last Verified: Cosing database,ifra standards

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides the defining fresh citrus fragrance note alongside solvent and antimicrobial properties.

Why It's Used: The citrus industry's primary fragrance compound and the most abundant terpene in essential oils – limonene provides the clean, universally appealing fresh citrus scent character.

How It Works: D-limonene activates trpv1 mildly at high concentrations. antimicrobial via membrane disruption. solvent for oils and lipophilic compounds. cleaning via emulsification of lipid soils.

Typically Found In: Citrus-scented products,cleaning products,fragrance compounds

TECHNICAL DETAILS

Primary Category: Fragrance component – cyclic monoterpene

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.001%–3%

SOURCING & ETHICS

Vegan Status: Yes – from citrus peel essential oils

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: declared fragrance allergen. oxidises to sensitising compounds (limonene hydroperoxides) on air exposure – use with antioxidant stabilisers. ifra guidelines apply.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Limonene's sensitisation risk arises not from limonene itself but from its autooxidation products (limonene-1,2-epoxide and limonene hydroperoxides) formed on air exposure. fresh limonene has low sensitisation potential, but air-oxidised limonene's hydroperoxide products are potent skin sensitisers. this explains why oxidation-stabilised formulations (with bht or other antioxidants) are required to manage limonene safety.

Last Verified: Cosing database,ifra standards,bråred christensson et al. limonene oxidation study

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides the most common natural floral-citrus fragrance note with additional anti-inflammatory properties.

Why It's Used: The most abundant fragrance terpene in nature – linalool forms the primary scent character of lavender, responsible for lavender's documented aromatherapy calming effects.

How It Works: Monoterpene alcohol activates gaba-a receptors for anti-anxiety activity (same receptor as benzodiazepines). inhibits glutamate-induced excitotoxicity. antimicrobial via membrane disruption. anti-inflammatory via nf-kb inhibition.

Typically Found In: Virtually all fragranced cosmetics

TECHNICAL DETAILS

Primary Category: Fragrance component – tertiary terpene alcohol

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.001%–3%

SOURCING & ETHICS

Vegan Status: Yes – from lavender, coriander, bergamot

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: declared fragrance allergen on label when >0.001% (leave-on) or >0.01% (rinse-off). ifra guidelines apply.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Linalool's gaba-a receptor activation provides a pharmacological basis for lavender aromatherapy's documented anxiolytic effects. the same receptor modulation used by benzodiazepine drugs (such as diazepam) is activated by inhaled linalool vapor, providing receptor-mediated calming without the tolerance and dependence associated with pharmaceutical gaba-a modulators.

Last Verified: Cosing database,ifra standards,elisabetsky et al. linalool gaba study

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides potent antioxidant protection, activates anti-aging sirtuin pathways, and reduces inflammation.

Why It's Used: Premium anti-aging antioxidant targeting sirt1-mediated longevity pathways alongside strong direct antioxidant and anti-inflammatory activity.

How It Works: Direct free radical scavenging via hydroxystilbene phenolic groups. activates sirt1 deacetylase, promoting mitochondrial biogenesis and dna repair. inhibits nf-kb for anti-inflammatory effects. may block tyrosinase for mild brightening.

Typically Found In: Premium anti-aging serums,antioxidant complexes,anti-inflammatory products

TECHNICAL DETAILS

Primary Category: Active ingredient – stilbene antioxidant

Secondary Functions: Sirtuin activation,anti-inflammatory,longevity pathway

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–1%

SOURCING & ETHICS

Vegan Status: Yes – plant-derived or synthetic

Halal Status: Yes

Source Notes: Extracted from japanese knotweed (polygonum cuspidatum), grape skins, or synthesized. trans-form is bioactive; cis-form less active.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Generally well-tolerated; rare reports of contact sensitization at high concentrations.

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

Resveratrol's sirt1 activation promotes mitochondrial biogenesis via pgc-1α, potentially reversing age-related mitochondrial dysfunction in skin cells – the same longevity pathway activated by caloric restriction in model organisms.

Last Verified: Cosing database,baur & sinclair resveratrol review,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides potent antioxidant protection, activates anti-aging sirtuin pathways, and reduces inflammation.

Why It's Used: Premium anti-aging antioxidant targeting sirt1-mediated longevity pathways alongside strong direct antioxidant and anti-inflammatory activity.

How It Works: Direct free radical scavenging via hydroxystilbene phenolic groups. activates sirt1 deacetylase, promoting mitochondrial biogenesis and dna repair. inhibits nf-kb for anti-inflammatory effects. may block tyrosinase for mild brightening.

Typically Found In: Premium anti-aging serums,antioxidant complexes,anti-inflammatory products

TECHNICAL DETAILS

Primary Category: Active ingredient – stilbene antioxidant

Secondary Functions: Sirtuin activation,anti-inflammatory,longevity pathway

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–1%

SOURCING & ETHICS

Vegan Status: Yes – plant-derived or synthetic

Halal Status: Yes

Source Notes: Extracted from japanese knotweed (polygonum cuspidatum), grape skins, or synthesized. trans-form is bioactive; cis-form less active.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Generally well-tolerated; rare reports of contact sensitization at high concentrations.

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

Resveratrol's sirt1 activation promotes mitochondrial biogenesis via pgc-1α, potentially reversing age-related mitochondrial dysfunction in skin cells – the same longevity pathway activated by caloric restriction in model organisms.

Last Verified: Cosing database,baur & sinclair resveratrol review,cir safety assessment

Primary Sources: 2026-03-12