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 20,769
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

Humectant

Enteromorpha Flexuosa Extract

Enteromorpha Flexuosa Extract

4.0

A gentle seaweed extract that helps hydrate and calm the skin, with early research suggesting antioxidant benefits.

Irritation

low

Source

natural

beautyskincarehumectant
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Humectant

Enteromorpha Prolifera Water

ENTEROMORPHA PROLIFERA WATER

4.0

A gentle, hydrating seaweed water that adds light moisture and soothing benefits, ideal for sensitive or dehydrated skin.

Irritation

low

Source

natural

beautyskincarehumectant
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Antioxidant

Eperua Falcata Bark Extract

Eperua Falcata Bark Extract

3.8

Eperua Falcata Bark Extract is a gentle botanical antioxidant that may help calm skin and protect against environmental stress, though research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Ephedra Distachya Extract

EPHEDRA DISTACHYA EXTRACT

3.2

Ephedra Distachya Extract is a botanical ingredient with potential antioxidant benefits, but its use in skincare is not well-studied and may pose irritation risks for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarebotanical extract
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Soothing agent

Ephedra Sinica Root Extract

EPHEDRA SINICA ROOT EXTRACT

3.5

A plant root extract with potential soothing and antimicrobial benefits, but limited research and possible irritation risk for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarebotanical extract
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Soothing agent

Ephedra Sinica Water

EPHEDRA SINICA WATER

3.0

Ephedra Sinica Water may offer soothing and antimicrobial benefits, but its safety in skincare is not well-established and it may cause irritation for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarebotanical extract
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Antioxidant

Epigallocatechin Gallate

Epigallocatechin Gallate

4.3

A powerful antioxidant from green tea that helps protect skin from environmental damage and soothes irritation.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Epigallocatechin Gallatyl Glucoside

Epigallocatechin Gallatyl Glucoside

4.0

A modified green tea antioxidant that offers better stability and water solubility than plain EGCG, making it a gentle choice for daytime protection.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
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Soothing Agent

Epilobium Fleischeri Extract

EPILOBIUM FLEISCHERI EXTRACT

4.0

A gentle, antioxidant-rich alpine plant extract that may help calm redness and support skin barrier function, though human studies are limited.

Irritation

low

Source

natural

beautyskincarebotanical
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Soothing Agent

Epilobium Roseum Extract

EPILOBIUM ROSEUM EXTRACT

3.8

A gentle botanical extract that may help calm redness and provide antioxidant support, though research is still emerging.

Irritation

low

Source

natural

beautyskincarebotanical
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Antioxidant

Epimedium Grandiflorum Extract

EPIMEDIUM GRANDIFLORUM FLOWER/LEAF/STEM EXTRACT

3.8

A gentle plant extract with antioxidant potential, but research on its topical benefits is still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Epimedium Leaf/Stem Extract

Epimedium Sagittatum Leaf/Stem Extract

3.5

A plant extract with antioxidant potential, but limited skincare-specific research means its benefits are not yet well-established.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Epiphyllum Oxypetalum Callus Extract

Epiphyllum Oxypetalum Callus Extract

4.0

A gentle, antioxidant-rich plant extract from a rare cactus that may help soothe and protect skin, though human research is still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Epoxidized Juniper Extract

JUNIPERUS VIRGINIANA EXTRACT EPOXIDIZED

3.5

A modified juniper extract that may offer antioxidant benefits, but its epoxidized form is less studied and may pose irritation risks for sensitive skin.

Irritation

moderate

Source

semi-synthetic

beautyskincareantioxidant
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Antioxidant

Epoxidized Juniper Wood Extract

JUNIPERUS MEXICANA WOOD EXTRACT EPOXIDIZED

3.5

A semi-synthetic wood extract with antioxidant potential, but research is limited and it may not be a standout ingredient for most routines.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
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Plasticizer

Epoxidized Soybean Oil

EPOXIDIZED SOYBEAN OIL

3.0

A modified oil that helps formulas stay flexible and stable, but offers little direct skin benefit.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Film Former

Epoxy-Amine Film Former

Bis(Glycidoxyphenyl)Propane/Bisaminomethylnorbornane Copolymer

3.5

A synthetic film former that helps makeup last longer and resist water, but may feel stiff or heavy on the skin.

Irritation

low

Source

synthetic

beautyskincarefilm-former
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Fragrance Ingredient

Epoxycyclododecane

EPOXYCYCLODODECANE

3.5

Epoxycyclododecane is a synthetic fragrance ingredient that adds a woody scent, but it may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Epoxyguaiène

Epoxyguaiène

3.5

Epoxyguaiène is a rare, natural fragrance ingredient that adds a woody, ambery note and helps stabilize scent blends, but it's not a functional skincare active.

Irritation

low

Source

natural

beautyskincarefragrance
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Fragrance Ingredient

Epoxypinane

Epoxypinane

3.5

Epoxypinane is a synthetic pine-scented fragrance ingredient with limited safety data; it may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Antistatic Agent

Epoxypropyl Lauryldimonium Chloride

2,3-EPOXYPROPYL LAURYLDIMONIUM CHLORIDE

3.5

A synthetic conditioning agent that reduces static and softens hair, but may cause irritation for sensitive scalps.

Irritation

moderate

Source

synthetic

beautyhaircaresurfactant
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Antistatic Agent

Epoxypropyltrimonium Chloride

2,3-EPOXYPROPYLTRIMONIUM CHLORIDE

3.0

A reactive chemical used to make other ingredients more conditioning, but rarely appears as a standalone ingredient in consumer products.

Irritation

moderate

Source

synthetic

beautyskincarehaircare
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Film Former

Epsilon Caprolactone Copolymer

EPSILON CAPROLACTONE PEG/PPG-23/34 COPOLYMER

3.8

A gentle synthetic polymer that helps products spread smoothly and stay put, with low irritation risk.

Irritation

low

Source

synthetic

beautyskincarefilm-former
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Emollient

Equi Lipida

Equi Lipida

4.0

Equi Lipida is a gentle, lipid-rich ingredient that helps restore the skin barrier and lock in moisture, making it a good choice for dry or sensitive skin.

Irritation

low

Source

natural

beautyskincareemollient
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Antioxidant

Equol

Equol

3.8

Equol is a gentle antioxidant that may help even skin tone and support collagen, but human skincare studies are still limited.

Irritation

low

Source

biotech

beautyskincareantioxidant
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Other

Erbium Chloride

ERBIUM CHLORIDE

1.5

Erbium Chloride is a rare-earth salt with very limited cosmetic application; its safety and efficacy in skincare are not well-documented.

Irritation

moderate

Source

synthetic

beautyskincareother
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Emollient

Eremanthus Branch/Leaf Oil

EREMANTHUS ERYTHROPAPPUS BRANCH/LEAF OIL

3.5

A gentle, little-studied botanical oil that may offer antioxidant benefits, but lacks robust research to confirm efficacy.

Irritation

low

Source

natural

beautyskincarebotanical oil
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Fragrance

Eremanthus Erythropappus Leaf Oil

EREMANTHUS ERYTHROPAPPUS LEAF OIL

3.8

A fragrant botanical oil with potential soothing benefits, but limited research and a risk of skin irritation for sensitive individuals.

Irritation

moderate

Source

natural

beautyskincarefragrance
Read ingredient review

Soothing agent

Eremanthus Wood Extract

EREMANTHUS ERYTHROPAPPUS WOOD EXTRACT

3.8

A gentle botanical extract with antioxidant and soothing potential, though research is still emerging.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Fragrance

Eremophila Mitchellii Wood Oil

EREMOPHILA MITCHELLII WOOD OIL

3.8

A fragrant Australian wood oil with a calming scent, but limited research on direct skincare benefits and moderate irritation potential.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Skin conditioning agent

Ergocalciferol

Ergocalciferol

3.5

Ergocalciferol (vitamin D2) may support skin health and calm inflammation, but research in topical skincare is still emerging and it is less potent than vitamin D3.

Irritation

low

Source

natural

beautyskincarevitamin
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Skin Conditioning Agent

Ergosterol

Ergosterol

3.8

Ergosterol is a gentle, yeast-derived sterol that may support skin barrier function and antioxidant defense, but human skincare research is still limited.

Irritation

low

Source

natural

beautyskincareskin conditioning
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Antioxidant

Ergosterol Endoperoxide

Ergosterol Endoperoxide

3.5

Ergosterol endoperoxide is a promising but under-researched antioxidant that may help calm skin and fight free radicals, but it's not yet a mainstream ingredient.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Ergothioneine

Ergothioneine

4.3

Ergothioneine is a gentle, stable antioxidant that defends skin against pollution and UV damage without irritation, making it a smart addition to daytime skincare.

Irritation

low

Source

natural

beautyskincareantioxidant
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Soothing Agent

Erica Arborea Root Extract

Erica Arborea Root Extract

3.8

A gentle botanical extract with antioxidant potential, but research on its specific skin benefits is still limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Antioxidant

Erica Canaliculata Extract

Erica Canaliculata Flower/Leaf/Stem Extract

3.8

A gentle botanical extract with antioxidant potential, but research is limited—best as a supporting ingredient in soothing formulations.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Erica Cinerea Flower Extract

ERICA CINEREA FLOWER EXTRACT

3.8

A gentle botanical extract with antioxidant potential, but research on its skincare benefits is still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Film Former

Ericerus Pela Wax

ERICERUS PELA CERA

3.5

A natural insect wax that helps thicken and stabilize cosmetic formulas with a low risk of irritation.

Irritation

low

Source

natural

beautyskincarewax
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Antioxidant

Eriodictyol

Eriodictyol

3.8

Eriodictyol is a plant-derived antioxidant that may help protect skin from environmental damage and support a more even complexion, though human studies are limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Humectant

Erman's Birch Sap

Betula Ermanii Sap

4.0

A gentle, hydrating sap from birch trees that may help soothe and lightly moisturize the skin, but scientific evidence is still limited.

Irritation

low

Source

natural

beautyskincarehumectant
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Antioxidant

Erman's Birch Stem Extract

Betula Ermanii Stem Extract

4.0

A gentle, plant-based antioxidant that may help calm skin and defend against environmental stress, though research is still early.

Irritation

low

Source

natural

beautyskincareantioxidant
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Preservative

Erucalkonium Chloride

Erucalkonium Chloride

3.5

Erucalkonium chloride is an effective preservative and antistatic agent for hair products, but it may cause mild irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarepreservative
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Slip Agent

Erucamide

ERUCAMIDE

3.5

Erucamide is a synthetic lubricant that improves the glide and feel of makeup and skincare, with a strong safety record at low use levels.

Irritation

low

Source

synthetic

beautyskincareemollient
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Surfactant

Erucamidopropyl Hydroxysultaine

Erucamidopropyl Hydroxysultaine

4.0

A gentle, effective surfactant that creates rich foam without stripping the skin, making it a great choice for sensitive or dry skin types.

Irritation

low

Source

semi-synthetic

beautyskincarecleanser
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Cleansing Agent

Erucic Acid

ERUCIC ACID

3.5

Erucic acid is a gentle fatty acid that helps cleanse and condition skin and hair, but it may be slightly comedogenic for acne-prone individuals.

Irritation

low

Source

natural

beautyskincarecleansing agent
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Emollient

Erucyl Arachidate

ERUCYL ARACHIDATE

4.0

Erucyl Arachidate is a gentle, non-greasy emollient that helps soften and smooth skin without clogging pores.

Irritation

low

Source

synthetic

beautyskincareemollient
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Emollient

Erucyl Erucate

ERUCYL ERUCATE

4.0

A lightweight, plant-derived emollient that softens skin and improves product texture with a low risk of irritation or clogged pores.

Irritation

low

Source

natural

beautyskincareemollient
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Emollient

Erucyl Oleate

Erucyl Oleate

4.0

Erucyl Oleate is a gentle emollient that softens and smooths skin without feeling greasy, making it a good choice for dry or sensitive skin.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Antioxidant

Erythorbic Acid

Erythorbic Acid

4.0

Erythorbic acid is a gentler, more stable alternative to L-ascorbic acid that helps brighten skin and fight free radicals.

Irritation

low

Source

synthetic

beautyskincareantioxidant
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Soothing Agent

Erythrina Variegata Flower Water

ERYTHRINA VARIEGATA FLOWER WATER

3.8

A mild, aromatic floral water that offers gentle soothing and antioxidant benefits, but with limited research specific to skincare.

Irritation

low

Source

natural

beautyskincaresoothing
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Soothing Agent

Erythrina Variegata Leaf Extract

Erythrina Variegata Leaf Extract

3.8

A gentle botanical extract with antioxidant and soothing potential, though research is still early and benefits are not yet proven in large human studies.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Humectant

Erythritol

Erythritol

4.0

Erythritol is a gentle, non-irritating humectant that helps hydrate skin without stickiness, making it a great alternative to glycerin for sensitive or acne-prone skin.

Irritation

low

Source

natural

beautyskincarehumectant
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