Olay Retinol 24 Night Smoothing Serum

DESCRIPTION

What It Does: Provides lightweight non-polar emolliency from the hydrocarbon chain.

Why It's Used: C13-14 isoparaffin is selected for hydrocarbon emolliency — the non-polar alkane or alkene chain provides clean-rinse lightweight conditioning with no ester or silicone residue for formulators seeking a minimal-footprint emollient.

How It Works: Hydrocarbon chain: non-polar → low surface energy → fast-spreading emolliency; no ester or silicone chemistry → clean formulation profile.

Typically Found In: Cosmetic 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

Safety documented in cosing at standard formulation concentrations.

Last Verified: Cosing database,c13-14 isoparaffin technical review

Primary Sources: 2026-03-22

DESCRIPTION

What It Does: Provides silicone-characteristic silky feel and skin protection with adjustable viscosity.

Why It's Used: The benchmark cosmetic silicone – sets the gold standard for silky application feel, spreadability, and skin protection in virtually all skin care categories.

How It Works: Polydimethylsiloxane chain flexibility provides extremely low surface tension and high spreadability. inert si-o backbone provides chemical stability and excellent skin tolerance. occlusive film formation reduces tewl. higher viscosity grades provide more intense conditioning.

Typically Found In: Moisturizers,foundations,primers,sunscreens – nearly universal

TECHNICAL DETAILS

Primary Category: Functional ingredient – polydimethylsiloxane

Secondary Functions: Barrier sealing,softening

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–30%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

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

Dimethicone's exceptional silky feel arises from its very low intermolecular attractive forces (weak van der waals forces due to non-polar methyl groups) that allow silicone chains to slide freely over skin. the coefficient of kinetic friction for pdms against skin (~0.04) is among the lowest of any cosmetic material – explaining why even small amounts transform product feel.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

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

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

Last Verified: Cosing database,dimethiconol technical literature

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: 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

Laureth-4 has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,laureth-4 technical literature

Primary Sources: 2026-03-12

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

Laureth-7 has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,laureth-7 technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Niacinamide strengthens the skin barrier, reduces visible pore size, regulates sebum production, fades dark spots, and improves skin texture and tone.

Why It's Used: It is used because it addresses multiple skin concerns at once without irritation, making it suitable for all skin types. it is stable in formulations and pairs well with most other actives.

How It Works: Niacinamide inhibits the transfer of melanosomes (pigment packets) to skin cells, reducing hyperpigmentation. it also stimulates ceramide synthesis to strengthen the skin barrier and reduces inflammation by modulating cytokine activity.

Typically Found In: Serums,moisturizers,toners,cleansers,eye creams,sunscreens,primers

TECHNICAL DETAILS

Primary Category: Active ingredient – vitamin

Secondary Functions: Barrier repair,brightening,anti-inflammatory

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 2%–10% (typical: 5%; higher concentrations may cause flushing in some individuals)

SOURCING & ETHICS

Vegan Status: Yes – synthetically produced

Halal Status: Yes – synthetic origin

Source Notes: Commercially produced via synthesis from nicotinic acid or 3-cyanopyridine. no animal-derived sources used in cosmetic-grade niacinamide.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low; concentrations above 10% may cause temporary flushing in sensitive individuals

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: At concentrations >10%, some users experience niacin flush (transient redness/tingling). generally very well-tolerated.

Safe for Sensitive Skin: Yes – one of the best-tolerated actives for sensitive skin

SAFETY & COMPATIBILITY

Safety Profile: Extensively studied and considered very safe. ewg hazard score: 1. no significant systemic toxicity concerns at topical concentrations.

Works Well With: Retinol,peptides,ahas/bhas,hyaluronic acid,ceramides,zinc,vitamin c,spf

Avoid Combining With: High concentrations of vitamin c (ascorbic acid) may theoretically convert to niacin – use at different times if using pure l-ascorbic acid above 15%

SCIENTIFIC NOTE

Niacinamide is a precursor to nad+ and nadp+, coenzymes vital to cellular energy metabolism. its benefits for dna repair and mitochondrial function make it a key ingredient in anti-aging strategies.

Last Verified: Cosing database,cir safety assessment,ewg skin deep,pubmed clinical studies

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Stimulates collagen types i, iii, and iv synthesis in fibroblasts, reducing wrinkles and firming skin.

Why It's Used: Clinically proven signal peptide and the original matrixyl with the strongest evidence base for wrinkle reduction via collagen stimulation. cornerstone of peptide anti-aging formulations.

How It Works: Palmitoyl moiety enables stratum corneum penetration. pal-kttks peptide sequence mimics collagen type i procollagen fragment activating tgf-beta receptor-mediated collagen synthesis in fibroblasts. also stimulates fibronectin and hyaluronan production.

Typically Found In: Anti-aging serums,anti-wrinkle creams,eye treatments,neck creams

TECHNICAL DETAILS

Primary Category: Active ingredient – matrikine signal peptide

Secondary Functions: Collagen type i stimulation,wrinkle reduction,skin firming

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1–1000 ppm (typically 3–200 ppm)

SOURCING & ETHICS

Vegan Status: Yes – synthetically produced

Halal Status: Yes

Source Notes: Synthesized by solid-phase peptide synthesis (spps) followed by palmitoylation. commercially supplied in aqueous solution (matrixyl by sederma).

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; suitable for all skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

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

Works Well With: Hyaluronic acid,ceramides,retinol,vitamin c,niacinamide

Avoid Combining With: Avoid mixing with high-concentration ahas at same ph (may hydrolyze peptide bonds)

SCIENTIFIC NOTE

Lintner & mas-chamberlin (2002) demonstrated pal-kttks upregulates collagen i, iii, and iv as well as fibronectin in fibroblast cultures. a 2.0 ppm clinical trial showed statistically significant wrinkle depth reduction after 4 weeks.

Last Verified: Cosing database,lintner & mas-chamberlin (2002) matrixyl study,gorouhi & maibach peptide review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Retinol accelerates skin cell turnover, stimulates collagen production, reduces fine lines and wrinkles, fades hyperpigmentation, and helps normalize pore size.

Why It's Used: It is the most evidence-backed anti-aging ingredient available without a prescription. it provides comprehensive skin renewal benefits that no other single cosmetic ingredient can match.

How It Works: Retinol is converted in the skin to retinoic acid, which binds to retinoid receptors in cell nuclei. this activates gene expression changes that accelerate cell turnover, boost collagen synthesis, and inhibit matrix metalloproteinases (collagen-degrading enzymes).

Typically Found In: Night creams,serums,eye creams,targeted treatment products,anti-aging formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – vitamin a derivative

Secondary Functions: Exfoliating,anti-acne,brightening

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.025%–1% (otc); start at low concentrations and build up slowly

SOURCING & ETHICS

Vegan Status: Conditional – can be animal-derived (fish liver, egg yolk) or synthetic; verify source

Halal Status: Conditional – verify source; synthetic retinol is halal

Source Notes: Cosmetic retinol is predominantly synthetically manufactured. some natural sources include fish liver oils. synthetic is preferred for purity and sustainability.

SKIN COMPATIBILITY

Irritancy Rating: 3/5 – moderate; can cause dryness, peeling, redness, especially during adjustment period (retinization)

Comedogenicity Rating: 0/5 – non-comedogenic; actually helps clear pores

Sensitivity Concerns: Retinization period: 2–6 weeks of potential dryness, flaking, and sensitivity. photosensitizing – must use spf when using retinol. avoid during pregnancy.

Safe for Sensitive Skin: Use with caution – start at 0.025%, buffer with moisturizer, use every 2–3 nights initially

SAFETY & COMPATIBILITY

Safety Profile: Safe for general use at otc concentrations. not recommended during pregnancy. avoid with waxing. use spf daily. ewg hazard score: varies by concentration.

Works Well With: Niacinamide (soothes irritation),peptides,ceramides,hyaluronic acid,spf (mandatory)

Avoid Combining With: Benzoyl peroxide (may inactivate retinol),ahas/bhas (when new to retinol – overexfoliation risk),vitamin c (use at different times)

SCIENTIFIC NOTE

Retinol is approximately 20 times less potent than prescription tretinoin (retinoic acid) but significantly better tolerated. the conversion rate of retinol to retinoic acid in skin is the rate-limiting step in its efficacy.

Last Verified: Cosing database,cir safety assessment,journal of investigative dermatology,kligman et al. studies

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Promotes skin cell renewal and collagen support with a gentle activity profile.

Why It's Used: Stable, gentle retinoid ester for sensitive skin where tolerability is a priority.

How It Works: Enzymatic hydrolysis releases retinol from propionate ester for standard retinoid metabolic activation.

Typically Found In: Anti-aging creams,night serums,eye creams

TECHNICAL DETAILS

Primary Category: Active ingredient – vitamin a derivative

Secondary Functions: Collagen support,texture refinement

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.01%–0.5%

SOURCING & ETHICS

Vegan Status: Conditional – verify source

Halal Status: Conditional – verify source

Source Notes: Predominantly synthetic. slightly more lipophilic than retinyl acetate.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Introduce slowly; retinization expected at higher potencies.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Safe at cosmetic concentrations. use spf. avoid during pregnancy. ewg score: 2.

Works Well With: Niacinamide,ceramides,hyaluronic acid,spf,tocopherol

Avoid Combining With: Pregnancy; extended uv without spf; benzoyl peroxide

SCIENTIFIC NOTE

The c3 propionate ester is slightly more lipophilic than acetate, potentially improving stratum corneum penetration while maintaining a gentle release profile.

Last Verified: Cosing database,cir retinol safety assessment

Primary Sources: 2026-03-12