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

Fragrance

Hydrocinnamyl Propionate

HYDROCINNAMYL PROPIONATE

3.5

A synthetic fragrance ester that adds a sweet, floral scent to products; generally considered safe at low concentrations but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Propellant

Hydrofluorocarbon 227ea

HYDROFLUOROCARBON 227EA

3.5

A synthetic propellant that helps spray products work smoothly, but it has a high global warming potential and is being phased out in some regions.

Irritation

low

Source

synthetic

beautyskincarepropellant
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Antioxidant

Hydrogen

HYDROGEN

3.5

Hydrogen is a trendy antioxidant ingredient that may help calm skin, but its benefits in topical skincare are still being studied and are not yet proven in large human trials.

Irritation

low

Source

synthetic

beautyskincareantioxidant
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Film Former

Hydrogen Dimethicone

Hydrogen Dimethicone

4.0

Hydrogen Dimethicone is a gentle silicone that smooths and protects skin and hair without clogging pores or causing irritation.

Irritation

low

Source

synthetic

beautyskincarehaircarefilm-former
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Emollient

Hydrogen Diphenyl Dimethicone

Hydrogen Diphenyl Dimethicone

4.0

A gentle silicone that smooths skin and hair without clogging pores, making it a reliable choice for most skin types.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Antimicrobial

Hydrogen Peroxide

Hydrogen Peroxide

2.5

Hydrogen peroxide can kill bacteria and lighten skin, but it's harsh and can damage healthy skin cells, making it a risky choice for routine skincare.

Irritation

moderate

Source

synthetic

beautyskincareantimicrobial
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Emollient

Hydrogenated Argan Oil

Hydrogenated Argania Spinosa Kernel Oil

4.3

A stable, non-greasy emollient that locks in moisture and improves product texture, ideal for dry or sensitive skin.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Emollient

Hydrogenated Avocado Oil

Hydrogenated Avocado Oil

4.0

A gentle, non-greasy emollient that strengthens the skin barrier and is well-tolerated by most skin types.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Emollient

Hydrogenated Baobab Seed Oil

HYDROGENATED ADANSONIA DIGITATA SEED OIL

4.0

A gentle, non-greasy emollient that locks in moisture and gives products a smooth, velvety feel.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Soothing Agent

Hydrogenated Bisabolol

Hydrogenated Bisabolol

4.5

A gentle, stabilized version of chamomile-derived bisabolol that helps calm irritated skin without causing breakouts.

Irritation

low

Source

semi-synthetic

beautyskincaresoothing agent
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Antioxidant

Hydrogenated Calamus Root Extract

ACORUS CALAMUS ROOT EXTRACT HYDROGENATED

3.5

A gentle, processed root extract that may help calm skin and fight free radicals, but research is still limited.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
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Emollient

Hydrogenated Camelina Oil

HYDROGENATED CAMELINA SATIVA SEED OIL

4.0

A gentle, plant-based emollient that locks in moisture without clogging pores—great for dry or sensitive skin.

Irritation

low

Source

natural

beautyskincareemollient
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Emollient

Hydrogenated Camellia Seed Oil

HYDROGENATED CAMELLIA OLEIFERA SEED OIL

4.3

A gentle, non-greasy emollient that locks in moisture and gives a silky feel — great for dry or sensitive skin.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Emulsifier

Hydrogenated Castor Oil Ethoxylate

PEG-40 HYDROGENATED CASTOR OIL

4.0

A reliable, low-irritation emulsifier that helps mix oil and water in your skincare products, but may feel slightly heavy on very oily skin.

Irritation

low

Source

semi-synthetic

beautyskincaresurfactant
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Emulsifier

Hydrogenated Castor Oil PEG-8 Esters

Hydrogenated Castor Oil PEG-8 Esters

4.0

A gentle, PEG-modified castor oil derivative that helps mix water and oil, making it a reliable emulsifier for stable, non-greasy formulas.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emollient

Hydrogenated Catnip Oil

HYDROGENATED NEPETA CATARIA OIL

3.5

A gentle, plant-derived emollient that softens skin with low irritation risk, though research on its unique benefits is still limited.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Emollient

Hydrogenated Didecene

Hydrogenated Didecene

4.0

A lightweight, non-greasy emollient that spreads easily and leaves skin feeling soft without clogging pores.

Irritation

low

Source

synthetic

beautyskincareemollient
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Emollient

Hydrogenated Didodecene

Hydrogenated Didodecene

4.0

A lightweight, synthetic emollient that improves product texture and leaves skin feeling silky without clogging pores.

Irritation

low

Source

synthetic

beautyskincareemollient
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Emollient

Hydrogenated Difarnesene

Hydrogenated Difarnesene

4.5

A next-generation, plant-derived emollient that feels lightweight and non-greasy, with a strong sustainability profile.

Irritation

low

Source

biotech

beautyskincareemollient
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Emulsifier

Hydrogenated Dimer Dilinoleth-80

Hydrogenated Dimer Dilinoleth-80

4.2

A gentle, plant-derived emulsifier that helps oil and water mix, making creams and lotions smooth and stable without irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emulsifier

Hydrogenated Ditallowamine

Hydrogenated Ditallowamine

3.5

An effective emulsifier and antistatic agent, but may cause irritation or clog pores in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarehaircare
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Emollient

Hydrogenated Diterpene

HYDROGENATED DITERPENE

3.8

A gentle, plant-derived emollient that improves product texture and skin feel without clogging pores or causing irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Emollient

Hydrogenated Egg Oil

Hydrogenated Egg Oil

4.0

A gentle, nourishing emollient that helps soften and smooth skin without clogging pores.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Fragrance Ingredient

Hydrogenated Ethylbicycloheptane Guaiacol

HYDROGENATED ETHYLBICYCLOHEPTANE GUAIACOL

3.5

A synthetic fragrance ingredient that adds a warm, woody scent but has limited published safety data compared to more common fragrance materials.

Irritation

low

Source

synthetic

beautyskincarefragrance
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