OUAI Hydrating Scalp Serum

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

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

Last Verified: Cosing database,dextran technical literature

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: Provides warm clove fragrance note with local anaesthetic and antimicrobial properties.

Why It's Used: Natural local anaesthetic fragrance – eugenol provides clove's dual function as both a fragrance compound and a topical anaesthetic used in dentistry for pain relief.

How It Works: Activates trpv1 for local anaesthetic desensitisation (same mechanism as capsaicin but much weaker). inhibits cox and lox for anti-inflammatory activity. membrane disruption for antimicrobial activity. antioxidant via phenolic radical scavenging.

Typically Found In: Spice fragrances,dental products,clove-scented cosmetics

TECHNICAL DETAILS

Primary Category: Fragrance component – phenylpropanoid

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%–0.5%

SOURCING & ETHICS

Vegan Status: Yes – from clove essential oil (syzygium aromaticum)

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. sensitiser at high concentrations.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Eugenol's dental anaesthetic use predates modern pharmaceutical dentistry – oil of cloves (primarily eugenol) has been used for toothache relief for centuries. modern dentistry still uses eugenol in zinc oxide-eugenol cement for temporary cavity filling, where eugenol's trpv1 desensitisation provides pain relief while zinc oxide provides structural material – a pharmaceutical application of a fragrance compound still standard in clinical dentistry.

Last Verified: Cosing database,ifra standards,eugenol dental 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: Hyaluronic acid draws and locks moisture into the skin at multiple depths (surface and deeper layers depending on molecular weight), creating a plumping, smoothing, and hydrating effect.

Why It's Used: It is used because it is endogenous to human skin, making it exceptionally biocompatible and non-irritating. its unparalleled moisture-binding capacity makes it the most effective hydrating ingredient available.

How It Works: Ha binds water molecules through its many hydroxyl and carboxyl groups, creating a gel-like matrix. high molecular weight ha (>500 kda) hydrates the skin surface; low molecular weight ha (<50 kda) penetrates deeper to provide interior hydration.

Typically Found In: Serums,moisturizers,sheet masks,toners,eye creams,lip treatments,dermal fillers (injectable)

TECHNICAL DETAILS

Primary Category: Active ingredient – humectant/hydrator

Secondary Functions: Barrier repair,plumping,anti-aging

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–2% (effective at very low concentrations; multi-weight ha provides superior results)

SOURCING & ETHICS

Vegan Status: Yes – biotechnology-derived (microbial fermentation of streptococcus equi or b. subtilis); vegan-certified versions widely available

Halal Status: Yes

Source Notes: Originally extracted from rooster combs; now predominantly produced via biotechnology (bacterial fermentation), which is vegan and more sustainable.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low; one of the gentlest skincare ingredients known

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: In very dry environments, high-molecular-weight ha on the surface can potentially draw moisture out of the skin if not sealed with an occlusive. apply to damp skin and seal with moisturizer.

Safe for Sensitive Skin: Yes – ideal for all skin types including rosacea, eczema, and post-procedure skin

SAFETY & COMPATIBILITY

Safety Profile: Exceptional safety profile. endogenous molecule – no toxicity concerns. ewg hazard score: 1. safe during pregnancy.

Works Well With: Virtually all ingredients; especially ceramides,glycerin,peptides,retinol (reduces irritation),niacinamide,vitamin c

Avoid Combining With: No significant incompatibilities; high concentrations of alcohol in a formula may reduce its efficacy

SCIENTIFIC NOTE

Hyaluronic acid naturally degrades in skin (half-life ~1–2 days). the skin produces it endogenously, but production decreases with age. multi-molecular-weight ha formulas provide hydration at both surface and deeper skin levels.

Last Verified: Cosing database,cir safety assessment,papakonstantinou et al. (2012) dermato-endocrinology

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides the functional class benefits described by the 'peptides' category — specific activity depends on the precise ingredient within this functional class.

Why It's Used: Used as a category label when listing ingredient classes rather than specific inci names — relevant for consumer-facing communication and ingredient disclosure frameworks.

How It Works: Activity depends on specific ingredient within the category; the category designation indicates the broad functional mechanism shared by all members of the group.

Typically Found In: Consumer communication,ingredient disclosure

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: Varies

SOURCING & ETHICS

Vegan Status: Varies

Halal Status: Varies

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

Peptides as a category encompasses multiple specific inci ingredients each with individual safety and efficacy profiles; see individual ingredient entries for specific mechanistic detail.

Last Verified: Cosing database,functional category descriptor

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: Deposits a conditioning film on hair and skin through electrostatic attraction to negative cuticle/corneocyte surfaces, reduces hair-on-hair friction for improved combability and detangling, eliminates static charge buildup, and provides anti-frizz humidity resistance.

Why It's Used: Cationic polymers are the primary hair conditioning technology — the permanent positive quaternary ammonium groups provide substantive deposition that resists rinsing, delivering persistent conditioning between washes unlike small-molecule cationic conditioners.

How It Works: At shampoo/conditioner ph 4.5–5.5, hair cuticle carries net negative charge (isoelectric point ph ~3.5). polyquaternium cations undergo electrostatic attraction depositing on the cuticle surface. during rinsing, the deposited polymer film persists from reduced surface-solution equilibrium at low bulk concentration — substantive deposition from favourable interfacial versus bulk partitioning.

Typically Found In: Shampoos,conditioners,leave-in products

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%–3%

SOURCING & ETHICS

Vegan Status: Yes

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

Different polyquaternium numbers indicate different backbone chemistries: pq-7 (acrylamide/quaternary acrylate copolymer) for leave-on flexibility; pq-10 (hydroxyethylcellulose/quaternary ammonium) for substantive deposition; pq-11 (vp/dimethylaminoethyl methacrylate) for styling fixation.

Last Verified: Cosing database,polyquaternium-7 cationic conditioning deposition review

Primary Sources: 2026-03-12

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: 1899-12-31 00:00:00 -0800

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: 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