Paula's Choice Resist Perfectly Balanced Foaming Cleanser

DESCRIPTION

What It Does: Provides versatile acrylic film formation and thickening across broad ph range.

Why It's Used: Versatile workhorse polymer for film formation and thickening across diverse cosmetic product types from acidic aha serums to alkaline cleansers.

How It Works: Copolymer of acrylic acid and methacrylic acid esters. thickens via polymer chain entanglement and electrostatic repulsion. film formation from chain entanglement on water evaporation. broad ph stability from balanced acid/neutral monomer composition.

Typically Found In: Serums,lotions,sunscreens — versatile across formulation types

TECHNICAL DETAILS

Primary Category: Functional ingredient – acrylic film former

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 – 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

Acrylates copolymers' broad ph thickening stability (vs carbomer's ph-sensitive thickening, requiring neutralisation for viscosity) enables thickening of acidic aha serums (ph 3-4) without neutralisation — maintaining the low ph required for aha efficacy while providing viscosity control. this acid-stable thickening is impossible with conventional carbomers.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides antioxidant protection from reactive oxygen species, reduces inflammatory cytokine production in skin, and conditions skin surface through the plant's secondary metabolite complex.

Why It's Used: Chosen for its natural origin narrative, traditional use heritage, and multi-functional phytochemical profile that supports several concurrent skin care claims from one ingredient.

How It Works: Polyphenols, terpenoids, and alkaloids in the extract scavenge ros via hydrogen atom transfer, inhibit nf-kb or cox-2 inflammatory pathways, and interact with skin surface proteins for conditioning.

Typically Found In: Botanical skin care,natural products

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: 0.1%–10%

SOURCING & ETHICS

Vegan Status: Yes

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

Plant secondary metabolites evolved as uv photoprotectants and antimicrobial agents — mechanisms that directly translate to cosmetic antioxidant and anti-inflammatory activity in human skin.

Last Verified: Cosing database,aloe barbadensis leaf extract botanical review

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: Provides the most potent antimicrobial diol activity alongside skin feel enhancement.

Why It's Used: Premium antimicrobial diol — caprylyl glycol's c8 chain provides the strongest membrane-disrupting antimicrobial activity of common diol preservative boosters with unique skin-feel enhancement.

How It Works: C8 1,2-diol: c8 chain length provides strongest bacterial and fungal membrane disruption of common diols. emollient skin feel improvement from c8 chain length interaction with skin surface. active at lower concentrations than shorter-chain diols. synergistic with ethylhexylglycerin.

Typically Found In: Natural preservation systems,skin feel enhancement

TECHNICAL DETAILS

Primary Category: Functional ingredient – antimicrobial humectant

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%

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

Caprylyl glycol's antimicrobial potency follows the chain-length dependent membrane activity of fatty acids: c8 is the optimal chain length for membrane disruption (same as caprylic acid's antimicrobial optimum), providing maximum membrane integration without the skin sensitisation associated with longer chain lengths. this chain-length pharmacophore relationship is why c8 > c6 > c5 in diol antimicrobial potency despite identical head group chemistry.

Last Verified: Cosing database,schülke sensiva sc 50 technical data,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides transparent gel textures and thickening at very low concentrations via ph-responsive swelling.

Why It's Used: The most widely used gel thickener – provides crystal-clear, stable gels at concentrations as low as 0.1-0.5% with ph-controlled viscosity.

How It Works: Highly crosslinked polyacrylic acid remains tightly coiled at acidic ph. neutralization with naoh or triethanolamine ionizes carboxylic groups causing electrostatic repulsion that unfolds and swells the polymer coils, dramatically increasing viscosity. concentration-dependent thickening.

Typically Found In: Gels,serums,emulsions,sunscreens

TECHNICAL DETAILS

Primary Category: Functional ingredient – polyacrylic acid thickener

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%–2%

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

Carbomer's ph-responsive swelling mechanism provides an elegant formulation control tool: a neutralized gel can be liquefied by ph reduction (adding acid) and re-thickened by reneutralization. this reversible rheology control allows two-phase products that mix on application without the need for mechanical emulsification.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides alpha-hydroxy ceramide for complementary barrier repair alongside ceramide np and eop.

Why It's Used: Essential barrier ceramide trio component — ceramide ap's alpha-hydroxy fatty acid provides the specific lamellar body formation chemistry needed for complete barrier restoration with ceramide np and ceramide eop.

How It Works: N-(2-hydroxyfatty acid) phytosphingosine: 2-hydroxylation of fatty acid is critical for optimal packing of ceramide ap in lamellar lipid bilayers. the alpha-hydroxy group creates stronger intermolecular hydrogen bonding between ceramide ap molecules than non-hydroxylated ceramides. used in combination with ceramide np and ceramide eop for comprehensive barrier repair.

Typically Found In: Complete barrier repair formulas,triple ceramide systems,eczema treatment

TECHNICAL DETAILS

Primary Category: Active ingredient – alpha-hydroxy ceramide

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.01%–1%

SOURCING & ETHICS

Vegan Status: Conditional – plant-derived phytosphingosine available

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

The ceramide np + ceramide ap + ceramide eop triple combination mimics the natural ratio of ceramide classes in healthy stratum corneum (approximately 1:0.5:0.3 ratio). clinical studies comparing single ceramide vs triple ceramide barrier repair show significantly greater tewl reduction with triple ceramide combinations — the complementary molecular packing geometries of different ceramide classes creating a more complete lamellar bilayer than any single ceramide can provide.

Last Verified: Cosing database,elias & feingold barrier ceramide review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides the essential acylceramide scaffold for stratum corneum lamellar lipid organisation and barrier architecture.

Why It's Used: The architectural ceramide — ceramide eop's covalent corneocyte envelope binding is unique among ceramides and essential for organising the lamellar lipid matrix of the stratum corneum barrier.

How It Works: Omega-hydroxy ceramide esterified with linoleic acid at the omega-end. omega-hydroxyl group covalently bonds to involucrin/envoplakin proteins of corneocyte envelope via ester bond. this covalent anchor organises the lamellar lipid bilayers around each corneocyte. linoleate deficiency impairs this covalent anchoring — the biochemical basis of linoleic acid deficiency skin disease.

Typically Found In: Complete barrier repair systems,eczema treatment,omega-ceramide products

TECHNICAL DETAILS

Primary Category: Active ingredient – linoleate acylceramide

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: Conditional – plant-derived linoleate available

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

Ceramide eop's covalent corneocyte envelope binding is the only covalent interaction in the stratum corneum lipid structure — all other lamellar lipids interact via non-covalent van der waals and hydrogen bonds. this unique covalent anchoring of eop to the protein envelope provides the mechanical scaffold from which the entire lamellar lipid architecture is organised, making ceramide eop architecturally irreplaceable in barrier function.

Last Verified: Cosing database,holleran et al. ceramide eop review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides the most abundant natural skin ceramide for precise stratum corneum barrier lipid replacement.

Why It's Used: The primary skin ceramide — ceramide np's identity as the dominant stratum corneum ceramide fraction makes it the most physiologically relevant barrier lipid replacement for dry skin and eczema.

How It Works: N-stearoyl-phytosphingosine provides the exact molecular structure of the most abundant natural skin ceramide. integrates into stratum corneum lamellar lipid bilayers restoring barrier architecture. reduces tewl, improves corneometer moisture, restores barrier integrity. synergistic with cholesterol and fatty acids in barrier restoration.

Typically Found In: Barrier repair moisturisers,eczema care,dry skin treatment

TECHNICAL DETAILS

Primary Category: Active ingredient – phytosphingosine ceramide

Secondary Functions: Skin conditioning

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: Conditional – from wheat or phytosphingosine fermentation; plant-derived available

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

Ceramide np's structural identity to natural skin ceramide 3 (the dominant sc ceramide at approximately 18% of total sc ceramide fraction) means it integrates into the stratum corneum's lamellar bilayer structure with perfect molecular recognition. no other moisturising ingredient can achieve this level of structural identity to the natural barrier component it replaces — providing barrier repair rather than simply occlusive surface coating.

Last Verified: Cosing database,elias skin barrier ceramide review,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides fatty alcohol emulsification and thickening for stable, well-textured emulsions.

Why It's Used: The most widely used fatty alcohol in cosmetics – provides emulsification, thickening, and emolliency simultaneously from a single ingredient with excellent safety profile.

How It Works: Forms bilayer lamellar structures in water with emulsifiers creating a viscous structured network that thickens and stabilizes emulsions. fatty alcohol emolliency provides direct skin conditioning. bilayer formation reduces inter-droplet coalescence in emulsions.

Typically Found In: Creams,lotions,conditioners – virtually all emulsion products

TECHNICAL DETAILS

Primary Category: Functional ingredient – fatty alcohol emulsifier/thickener

Secondary Functions: Barrier sealing,softening

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–25%

SOURCING & ETHICS

Vegan Status: Yes – from vegetable or coconut/palm fatty acids

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

Cetearyl alcohol's ability to form lamellar liquid crystal structures ('krafft phases') with water and co-emulsifiers provides not only emulsion stability but also enhanced skin penetration via the lamellar skin barrier pathway. these crystalline structures can act as a reservoir for active ingredients, slowly releasing them as the lamellar structure melts on skin contact.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides essential barrier sterol function as one of three critical stratum corneum lipid components.

Why It's Used: Essential component of complete barrier repair formulations – the stratum corneum barrier requires ceramides:cholesterol:fatty acids in approximately 1:1:1 molar ratio for complete barrier restoration.

How It Works: Integrates between ceramide headgroups in lamellar body structures, providing fluidity and flexibility to the otherwise rigid ceramide-dominated lipid matrix. controls lamellar body phase behavior for functional barrier.

Typically Found In: Barrier repair moisturizers,eczema treatments,dry skin formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – barrier sterol

Secondary Functions: Lamellar body structure,barrier sterol

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.01%–1%

SOURCING & ETHICS

Vegan Status: Conditional – animal-derived (lanolin) or plant-derived phytosterol analogs; verify

Halal Status: Conditional – verify source

Source Notes: Traditionally from lanolin (wool grease). plant-derived cholesterol alternatives include phytosterols, though these show slightly different barrier integration. verify for vegan/halal.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Endogenous molecule; excellent tolerability.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Exceptional safety profile. natural skin component. ewg score: 1.

Works Well With: Other ceramides,cholesterol,free fatty acids,hyaluronic acid,niacinamide

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Elias demonstrated that barrier repair requires all three lipid classes (ceramides, cholesterol, fatty acids) in approximately equimolar ratios. formulations providing only ceramides without cholesterol and fatty acids show significantly inferior barrier restoration vs complete triple-lipid combinations.

Last Verified: Cosing database,elias et al. barrier lipid ratio study,loden barrier repair review

Primary Sources: 2026-03-12