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

Emulsifier

PEG-35 Almond Glycerides

PEG-35 ALMOND GLYCERIDES

4.0

A mild, almond-derived emulsifier that helps blend water and oil in creams and lotions without heavy irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-35 Castor Oil

PEG-35 Castor Oil

4.0

PEG-35 Castor Oil is a reliable emulsifier that helps mix oil and water, making it a staple in many cleansers and creams without causing irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-35 Hydrogenated Castor Oil

PEG-35 HYDROGENATED CASTOR OIL

4.0

A well-tolerated emulsifier that helps mix oil and water in your products, but may feel heavy on very oily skin.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emollient

PEG-35 Lanolin

PEG-35 Lanolin

3.8

A gentle, water-friendly lanolin derivative that moisturizes and helps blend oil and water in formulas, but may not suit those with wool allergies.

Irritation

low

Source

semi-synthetic

beautyskincareemollientemulsifier
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Emulsifier

PEG-35 Soy Glycerides

PEG-35 SOY GLYCERIDES

4.0

A reliable, low-irritation emulsifier that helps create smooth, stable creams and lotions without clogging pores.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-36 Castor Oil

PEG-36 Castor Oil

3.5

PEG-36 Castor Oil is a reliable emulsifier that helps mix water and oil, but its PEG component raises mild concerns about potential impurities in unrefined grades.

Irritation

low

Source

semi-synthetic

beautyskincaresurfactant
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Emulsifier

PEG-36 Oleate

PEG-36 Oleate

3.5

PEG-36 Oleate is a safe and effective emulsifier that helps mix oil and water, but it may be a concern for those avoiding ethoxylated ingredients.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-36 Stearate

PEG-36 Stearate

3.8

A reliable emulsifier that keeps creams and lotions stable, but may not be ideal for very sensitive or compromised skin.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Humectant

PEG-4

PEG-4

3.8

PEG-4 is a gentle, water-loving ingredient that helps hydrate the skin and improve product texture, but it may be contaminated with impurities in poorly refined forms.

Irritation

low

Source

synthetic

beautyskincarehumectant
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Emollient

PEG-4 Caprylic/Capric Triglyceride

CAPRYLIC/CAPRIC TRIGLYCERIDE PEG-4 ESTERS

3.8

A gentle, semi-synthetic emollient that helps products spread smoothly and feel silky, but may not suit those avoiding PEG compounds.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Emulsifier

PEG-4 Castor Oil

PEG-4 Castor Oil

4.0

A safe, effective emulsifier that helps mix oil and water in your products, with a low risk of irritation or clogged pores.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Surfactant

PEG-4 Cocamide

PEG-4 Cocamide

3.5

PEG-4 Cocamide is a common cleansing agent that helps remove dirt and oil, but may be drying or irritating for sensitive skin.

Irritation

moderate

Source

semi-synthetic

beautyskincaresurfactant
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Surfactant

PEG-4 Cocamine

PEG-4 Cocamine

3.5

PEG-4 Cocamine is a mild cleansing agent that helps products foam and rinse cleanly, but it may cause irritation for very sensitive skin.

Irritation

moderate

Source

semi-synthetic

beautyskincaresurfactant
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Emollient

PEG-4 Dicocoate

PEG-4 Dicocoate

3.8

A gentle synthetic emollient that helps products spread smoothly and feel less greasy, but may not suit those avoiding PEG compounds.

Irritation

low

Source

synthetic

beautyskincareemollient
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Emollient

PEG-4 Diheptanoate

PEG-4 Diheptanoate

3.8

A lightweight synthetic emollient that helps products glide on smoothly without a greasy feel, but it offers no active skincare benefits.

Irritation

low

Source

synthetic

beautyskincareemollient
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Emulsifier

PEG-4 Diisostearate

PEG-4 Diisostearate

3.5

A reliable synthetic emulsifier that helps mix oil and water, but may be slightly pore-clogging for acne-prone skin.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Dilaurate

PEG-4 Dilaurate

3.5

PEG-4 Dilaurate is a workhorse emulsifier that helps mix water and oil, but it may be slightly pore-clogging for acne-prone skin.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Film Former

PEG-4 Dimethacrylate

PEG-4 Dimethacrylate

3.5

A synthetic film-former that helps nail and makeup products last longer, but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarenail care
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Emulsifier

PEG-4 Dioleate

PEG-4 Dioleate

3.5

A synthetic emulsifier that helps mix oil and water, generally safe but may be too heavy for very oily skin.

Irritation

low

Source

synthetic

beautyskincaresurfactant
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Emulsifier

PEG-4 Distearate

PEG-4 Distearate

3.8

A safe, widely used synthetic emulsifier that helps blend oil and water in creams and lotions, but may not suit those avoiding ethoxylated ingredients.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Distearyl Ether

PEG-4 Distearyl Ether

4.0

A gentle synthetic emulsifier that helps create stable, creamy formulas without common irritation concerns.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Ditallow Ether

PEG-4 Ditallow Ether

3.5

An effective emulsifier from animal-derived tallow, but may cause irritation for sensitive skin and raises ethical concerns for vegans.

Irritation

moderate

Source

semi-synthetic

beautyskincaresurfactant
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Emollient

PEG-4 Ethylhexanoate

PEG-4 Ethylhexanoate

3.8

A lightweight synthetic emollient that softens skin without a greasy feel, generally well-tolerated but not a standout active ingredient.

Irritation

low

Source

synthetic

beautyskincareemollient
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Emulsifier

PEG-4 Glyceryl Distearate

PEG-4 Glyceryl Distearate

4.0

A gentle, semi-synthetic emulsifier that helps create stable, creamy textures with low irritation potential.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Glyceryl Tristearate

PEG-4 Glyceryl Tristearate

4.0

A gentle synthetic emulsifier that helps create stable, creamy textures in skincare without significant irritation or clogging concerns.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Isostearate

PEG-4 Isostearate

3.8

A reliable synthetic emulsifier that helps oil and water mix in your skincare, but it's not a star active ingredient.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emollient

PEG-4 Lanolate

PEG-4 Lanolate

3.8

PEG-4 Lanolate is a gentle, lanolin-derived emollient that softens skin and helps other ingredients absorb, but it may clog pores for acne-prone individuals.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Emulsifier

PEG-4 Laurate

PEG-4 Laurate

3.5

PEG-4 Laurate is a workhorse emulsifier that helps mix oil and water, but it may be mildly irritating or pore-clogging for sensitive or acne-prone skin.

Irritation

moderate

Source

synthetic

beautyskincareemulsifier
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Solvent

PEG-4 Methyl Ether

PEG-4 Methyl Ether

3.5

A gentle synthetic solvent and humectant that helps other ingredients dissolve and spread, but offers no unique skin benefit on its own.

Irritation

low

Source

synthetic

beautyskincaresolvent
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Emulsifier

PEG-4 Montanate

PEG-4 Montanate

3.5

A gentle synthetic emulsifier that helps mix water and oil in creams and lotions, with a low risk of irritation.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Oleamide

PEG-4 OLEAMIDE

3.5

PEG-4 Oleamide helps mix oil and water in cleansers and creams, but its synthetic nature and potential for irritation make it a cautious choice for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Oleate

PEG-4 Oleate

3.8

PEG-4 Oleate helps mix oil and water in products, but may be slightly irritating or pore-clogging for sensitive or acne-prone skin.

Irritation

moderate

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Olivate

PEG-4 Olivate

4.0

A gentle, olive-derived emulsifier that helps blend water and oil in cleansers and creams, with low irritation potential.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 PEG-12 Dimethicone

PEG-4 PEG-12 Dimethicone

4.0

A gentle silicone emulsifier that improves product texture and stability, generally safe for most skin types.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emollient

PEG-4 Proline Linoleate

PEG-4 Proline Linoleate

4.0

A gentle, semi-synthetic moisturizer that helps reinforce the skin barrier and improve hydration without clogging pores.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Skin conditioning agent

PEG-4 Proline Linolenate

PEG-4 Proline Linolenate

3.8

A gentle, semi-synthetic conditioning ingredient that may support skin barrier function, but research is limited and it's not a star performer on its own.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Surfactant

PEG-4 Rapeseedamide

PEG-4 RAPESEEDAMIDE

3.8

A gentle, plant-based cleansing agent that helps remove dirt and oil without stripping the skin.

Irritation

low

Source

semi-synthetic

beautyskincaresurfactant
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Emulsifier

PEG-4 Sorbitan Stearate

PEG-4 SORBITAN STEARATE

4.0

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

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Sorbitan Triisostearate

PEG-4 SORBITAN TRIISOSTEARATE

4.0

A reliable synthetic emulsifier that keeps water and oil mixed in creams and lotions, generally well-tolerated by most skin types.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Stearamide

PEG-4 Stearamide

3.5

A synthetic helper that blends oil and water in your products, but offers no direct skin benefit.

Irritation

low

Source

synthetic

beautyskincaresurfactant
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Emulsifier

PEG-4 Stearate

PEG-4 Stearate

3.8

PEG-4 Stearate is a safe, widely used emulsifier that helps products feel smooth, but it may be slightly pore-clogging for acne-prone skin.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-4 Tallate

PEG-4 TALLATE

3.5

PEG-4 Tallate is a functional emulsifier that helps mix oil and water, but it may be mildly irritating for sensitive skin and has moderate comedogenic potential.

Irritation

moderate

Source

semi-synthetic

beautyskincaresurfactant
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Emulsifier

PEG-40 Distearate

PEG-40 Distearate

3.8

A reliable synthetic emulsifier that stabilizes formulas but may not suit those avoiding ethoxylated ingredients.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-40 Glyceryl Cocoate

PEG-40 Glyceryl Cocoate

3.8

A gentle, coconut-derived emulsifier that helps cleansers foam and rinse cleanly without stripping the skin.

Irritation

low

Source

semi-synthetic

beautyskincarecleansingemulsifier
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Emulsifier

PEG-40 Glyceryl Isostearate

PEG-40 Glyceryl Isostearate

4.0

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

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Emulsifier

PEG-40 Glyceryl Stearate

PEG-40 Glyceryl Stearate

4.0

A gentle emulsifier that keeps oil and water mixed in creams and lotions, generally well-tolerated by most skin types.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

PEG-40 Glyceryl Trioleate

PEG-40 Glyceryl Trioleate

3.8

A reliable emulsifier that helps mix oil and water, but may be too heavy for very oily or acne-prone skin.

Irritation

low

Source

synthetic

beautyskincareemulsifier
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Surfactant

PEG-40 Hydrogenated Castor Oil

PEG-40 Hydrogenated Castor Oil

3.8

PEG-40 is a workhorse emulsifier that helps mix oil and water, but it may cause irritation for sensitive skin at high concentrations.

Irritation

moderate

Source

semi-synthetic

beautyskincaresurfactant
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