Beauty ingredient research

Beauty ingredients explained in plain English

Browse the review database to understand what an ingredient is, what it does in a beauty formula, when it is useful, and when it deserves caution across skincare, haircare, bodycare, makeup, and more.

20769

Reviewed ingredients

524

Low-concern standouts

2884

Need usage caution

Showing 60 of 20,303
AllUV absorberUV filterabrasiveabsorbentacne treatmentactiveactive ingredientadhesivealkalizing agentamino acidanti-aginganti-androgenanti-cavityanti-cavity agentanti-inflammatoryanti-irritantanticariesanticavity agentantidandruffantifungalantimicrobialantioxidantantiperspirantantiplaqueastringentbarrier repairbarrier supportbarrier-repairbarrier-supportbinderbinding agentbiotechbiotechnologybond-builderbotanicalbotanical extractbotanical oilbotanical waterbrighteningbrightening agentbufferbuffering agentcell-communicating ingredientceramidechelating agentchemicalchemical intermediateclaycleansercleansingcleansing agentcolorantconditionerconditioningconditioning agentcooling agentcosmeticcosmetic additivecosmetic colorantcosmetic ingredientcosmetic pigmentcosmetic powdercosmetic-texturizercosmetic-waxcosmeticscrosslinking agentdelivery agentdelivery systemdenaturantdeodorantdeodorant agentdepigmenting agentdepilatorydepilatory agentdesensitizing agentdyedye intermediatedye precursordye-intermediateemollientemulsifierenzymeessential oilexfoliantexperimentaleyelashfermentfilm formerfilm-formerfilm-formingfilm-forming agentfirming agentfixativeflavoring agentformulationfragrancefragrance ingredientfunctional ingredientgashair carehair colorhair coloranthair conditionerhair dyehair removalhair-carehair-colorhaircarehumectantindustrialinsecticideintermediatelashlash carelash enhancerlash-and-browlip carelipidmakeupmarine extractmasking agentmicrobiomemicrobiome modulatormineralmoisturizernail carenail-careocclusiveoilopacifieropacifying agentoptical agentoral careotheroxidative dyeoxidative dye precursoroxidizing agentpH adjusterpain reliefpenetration enhancerpeptidepersonal careph adjusterpharmaceuticalpheromonepigmentplant oilplasticizerpolymerpolymer precursorprebioticprescription-drugpreservativepreservative boosterprobioticprocessing agentprocessing aidpropellantproteinpurifyingreducing agentretinoidscalp caresebum regulatorsebum-regulatorself-tannerself-tanningsensory additivesensory agentsensory modifiersiliconeskin barrierskin barrier supportskin conditionerskin conditioningskin conditioning agentskin lighteningskin protectantskin-conditioningskin-conditioning agentskin-identicalskin-identical ingredientskin-lighteningskin-lightening agentskincaresolventsoothingsoothing agentstabilizerstimulantsunscreensurfactantsyntheticsynthetic colorantsynthetic dyesynthetic resinsynthetic-coloranttexture enhancertexturizerthickenertoneruv-absorberuv-filtervasoactivevasodilatorviscosity controlviscosity controllingviscosity controlling agentvitaminwax

Surfactant

PEG-40 Hydrogenated Tallow Amine

PEG-40 Hydrogenated Tallow Amine

3.5

A functional emulsifier that can help blend oils and water, but may be too heavy or irritating for sensitive or acne-prone skin.

Irritation

moderate

Source

semi-synthetic

beautyskincaresurfactant
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Emulsifier

PEG-40 Isostearate

PEG-40 Isostearate

4.0

A reliable emulsifier that helps create stable, creamy formulas without common irritation.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-40 Jojoba Acid

PEG-40 Jojoba Acid

4.0

A gentle, plant-derived emulsifier that helps blend oil and water in cleansers and creams, with a low risk of irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-40 Jojoba Alcohol

PEG-40 Jojoba Alcohol

4.2

A gentle, jojoba-derived emulsifier that helps mix oil and water without stripping the skin.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-40 Lanolin

PEG-40 Lanolin

3.8

A gentle, water-friendly emulsifier that helps blend oil and water in creams and cleansers, but may not suit those with wool allergies.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Surfactant

PEG-40 Methyl Ether

PEG-40 Methyl Ether

3.8

PEG-40 Methyl Ether is a synthetic surfactant that helps cleanse and emulsify, but may cause mild irritation for sensitive skin types.

Irritation

moderate

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Emulsifier

PEG-40 Olive Glycerides

PEG-40 Olive Glycerides

4.0

A mild, olive-derived emulsifier that helps mix oil and water in cleansers and creams, with a low risk of irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Film Former

PEG-40 Polyepsilon Caprolactone

BIS-METHOXY PEG-40 POLYEPSILON CAPROLACTONE

3.5

A synthetic polymer that helps products spread smoothly and form a light, flexible film on skin, but offers no active skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefilm-former
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Emulsifier

PEG-40 Ricinoleamide

PEG-40 Ricinoleamide

4.0

PEG-40 Ricinoleamide is a gentle emulsifier that helps mix oil and water in cleansers, but it may not suit those avoiding PEG compounds.

Irritation

low

Source

semi-synthetic

beautyskincaresurfactant
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Emulsifier

PEG-40 Sorbitan Lanolate

PEG-40 SORBITAN LANOLATE

4.0

A reliable, low-irritation emulsifier that helps blend oils and water, but may not suit those with lanolin sensitivity.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-40 Sorbitan Laurate

PEG-40 Sorbitan Laurate

3.8

A reliable emulsifier that keeps formulas stable, but may be too heavy for very oily or acne-prone skin.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-40 Sorbitan Oleate

PEG-40 Sorbitan Oleate

3.8

A widely used synthetic emulsifier that is generally safe and non-irritating for most skin types.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-40 Sorbitan Perisostearate

PEG-40 SORBITAN PERISOSTEARATE

3.8

A reliable synthetic emulsifier that helps blend oil and water, generally well-tolerated but may not suit those avoiding ethoxylated ingredients.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-40 Sorbitan Peroleate

PEG-40 SORBITAN PEROLEATE

3.8

A reliable emulsifier that helps oil and water mix, but may not suit those avoiding ethoxylated ingredients.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-40 Sorbitan Stearate

PEG-40 Sorbitan Stearate

4.0

A gentle, widely used emulsifier that helps create stable, creamy formulas without common irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-40 Sorbitan Tetraoleate

PEG-40 Sorbitan Tetraoleate

3.5

A reliable synthetic emulsifier that keeps oil and water mixed in your products, but it may not suit those avoiding ethoxylated ingredients.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-40 Soy Sterol

PEG-40 Soy Sterol

4.0

A well-tolerated emulsifier that helps create stable, creamy textures while offering mild skin conditioning.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
Read ingredient review

Solvent

PEG-400

PEG-400

3.5

PEG-400 is a widely used synthetic ingredient that helps dissolve other ingredients and improve texture, but its safety depends on purity and molecular weight.

Irritation

low

Source

synthetic

beautyskincaresolvent
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Emulsifier

PEG-41 Polybutylene Glycol Ether

HYDROGENATED DIMER DILINOLEYL PEG-41/POLY(1,2-BUTANEDIOL)-18 DIMETHYL ETHER

4.0

A gentle synthetic polymer that helps stabilize formulas and gives a smooth, non-greasy feel.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-42 Babassu Glycerides

PEG-42 Babassu Glycerides

4.0

A mild, semi-synthetic emulsifier derived from babassu oil that helps blend water and oil in cleansers and creams without stripping the skin.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emollient

PEG-42 Mushroom Glycerides

PEG-42 Mushroom Glycerides

3.5

A gentle, semi-synthetic emollient that helps soften skin and stabilize formulas, but research on its unique mushroom-derived benefits is still limited.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Emulsifier

PEG-44 Castor Oil

PEG-44 Castor Oil

4.0

A gentle emulsifier that helps mix oil and water in cleansers and shampoos, with a low risk of irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Thickener

PEG-44 Polybutylene Glycol Ether

HYDROGENATED DIMER DILINOLEYL PEG-44/POLY(1,2-BUTANEDIOL)-15 DIMETHYL ETHER

3.8

A synthetic polymer that helps create a smooth, non-greasy gel texture in skincare and haircare products, with a low irritation profile.

Irritation

low

Source

synthetic

beautyskincarehaircare
Read ingredient review

Surfactant

PEG-44 Sorbitan Laurate

PEG-44 Sorbitan Laurate

4.0

A gentle, water-soluble emulsifier that helps cleanse without stripping the skin's natural moisture barrier.

Irritation

low

Source

semi-synthetic

beautyskincaresurfactant
Read ingredient review

Emulsifier

PEG-45 Hydrogenated Castor Oil

PEG-45 Hydrogenated Castor Oil

3.8

A gentle, oil-based emulsifier that helps mix water and oil in formulas, but may feel heavy on very oily skin.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-45 Palm Kernel Glycerides

PEG-45 PALM KERNEL GLYCERIDES

3.8

A gentle emulsifier that helps blend oil and water in skincare products, generally well-tolerated but derived from palm kernel oil, which raises sustainability concerns.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-45 Safflower Glycerides

PEG-45 SAFFLOWER GLYCERIDES

4.0

A mild, plant-derived emulsifier that helps water and oil mix in your skincare, with a low risk of irritation or clogged pores.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-45 Stearate

PEG-45 Stearate

4.0

PEG-45 Stearate is a widely used emulsifier that helps create stable, creamy textures, but it may contain trace impurities from its manufacturing process.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-45 Stearate Phosphate

PEG-45 Stearate Phosphate

3.8

A reliable synthetic emulsifier that helps mix oil and water in creams and cleansers, but may not suit those avoiding PEG compounds.

Irritation

low

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Antioxidant

PEG-45 Thioctic Acid

METHOXY PEG-45 THIOCTATE

3.5

A PEG-modified form of alpha-lipoic acid that offers antioxidant benefits with improved water solubility and stability, but its effectiveness depends on formulation and concentration.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidantskin conditioning
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Film Former

PEG-45/Dodecyl Glycol Copolymer

PEG-45/Dodecyl Glycol Copolymer

3.8

A synthetic polymer that helps products stay put, resist water, and feel smooth, but offers no active skincare benefit.

Irritation

low

Source

synthetic

beautyskincarefilm-former
Read ingredient review

Thickener

PEG-450

PEG-450

3.8

PEG-450 is a safe, widely used synthetic thickener and humectant that helps stabilize formulas and improve texture, but it may be contaminated with impurities in poorly manufactured products.

Irritation

low

Source

synthetic

beautyskincarethickenerhumectant
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Film Former

PEG-450 Succinimide Ester

METHOXY PEG-450 AMIDO HYDROXYSUCCINIMIDYL SUCCINAMATE

3.5

A synthetic polymer that helps ingredients stick to skin and form a light, flexible film, but its large size means it stays on the surface and offers no deep hydration.

Irritation

low

Source

synthetic

beautyskincarefilm-former
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Thickener

PEG-45M

PEG-45M

4.0

PEG-45M is a safe, synthetic thickener that gives products a smooth, silky feel without clogging pores.

Irritation

low

Source

synthetic

beautyskincarethickener
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Emollient

PEG-5 Brazil Nut Oil Esters

PEG-5 BERTHOLLETIA EXCELSA SEED OIL GLYCERYL ESTERS

4.0

A gentle, semi-synthetic emollient that helps moisturize and stabilize formulas without feeling greasy.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Surfactant

PEG-5 Castor Oil

PEG-5 Castor Oil

3.8

A gentle emulsifier that helps blend oil and water in cleansers, but may be drying for some skin types.

Irritation

low

Source

semi-synthetic

beautyskincaresurfactant
Read ingredient review

Surfactant

PEG-5 Cocamide

PEG-5 Cocamide

3.5

PEG-5 Cocamide is a mild cleansing agent that helps foaming products work better, but it may be slightly drying for very sensitive skin.

Irritation

moderate

Source

semi-synthetic

beautyskincaresurfactant
Read ingredient review

Surfactant

PEG-5 Cocamine

PEG-5 Cocamine

3.5

An effective cleansing agent that helps remove dirt and oil, but may cause irritation for sensitive skin types.

Irritation

moderate

Source

semi-synthetic

beautyskincaresurfactant
Read ingredient review

Emulsifier

PEG-5 Cocoate

PEG-5 Cocoate

3.5

PEG-5 Cocoate helps mix oil and water in cleansers, but may be slightly drying or irritating for very sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Surfactant

PEG-5 DEDM Hydantoin

PEG-5 DEDM Hydantoin

3.5

A synthetic ingredient that helps products feel smooth and stay fresh, but may cause irritation for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarehaircare
Read ingredient review

Surfactant

PEG-5 DEDM Hydantoin Oleate

PEG-5 DEDM Hydantoin Oleate

3.5

A synthetic emulsifier that helps mix oil and water, but may be slightly drying or irritating for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Emollient

PEG-5 Ethylhexanoate

PEG-5 Ethylhexanoate

3.8

A gentle synthetic emollient that helps products feel silky without heavy greasiness, but offers no active skincare benefits.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emulsifier

PEG-5 Glyceryl Isostearate

PEG-5 Glyceryl Isostearate

3.8

A reliable synthetic emulsifier that helps create stable, creamy textures, but may be too heavy for very oily or acne-prone skin.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-5 Glyceryl Oleate

PEG-5 Glyceryl Oleate

3.8

A gentle emulsifier that helps blend oils and water, making cleansers and creams feel smooth without stripping the skin.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-5 Glyceryl Sesquioleate

PEG-5 Glyceryl Sesquioleate

3.5

A safe, effective emulsifier that helps your products feel smooth and stable, but it's synthetic and may not suit those avoiding PEGs.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-5 Glyceryl Stearate

PEG-5 Glyceryl Stearate

3.8

A gentle emulsifier that helps create stable, creamy textures without heavy irritation or clogging.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-5 Glyceryl Trioleate

PEG-5 Glyceryl Trioleate

3.8

A gentle synthetic emulsifier that helps mix water and oil in your skincare, but may not suit those avoiding PEG compounds.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-5 Glyceryl Tristearate

PEG-5 Glyceryl Tristearate

3.8

A reliable synthetic emulsifier that helps creams and lotions feel smooth and stable, but it offers no direct skin benefit.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-5 Hydrogenated Castor Oil

PEG-5 Hydrogenated Castor Oil

4.0

A reliable, low-irritation emulsifier that helps mix oil and water in cleansers and creams, but may not suit those avoiding PEG compounds.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

PEG-5 Hydrogenated Corn Glycerides

PEG-5 Hydrogenated Corn Glycerides

4.0

A gentle, semi-synthetic emulsifier derived from corn glycerides that helps stabilize creams and lotions without common irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
Read ingredient review

Emollient

PEG-5 Hydrogenated Lanolin

PEG-5 Hydrogenated Lanolin

3.8

A gentle, modified lanolin that softens skin and helps blend water and oil, but may clog pores in acne-prone individuals.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review