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

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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

Skin conditioning agent

Calcium Hydrolyzed Collagen

Calcium Hydrolyzed Collagen

3.8

A modified collagen that may help improve skin hydration and elasticity, but its calcium component adds little extra benefit for most people.

Irritation

low

Source

semi-synthetic

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Emollient

Camellia & Palm Amino Esters

CAMELLIA SINENSIS SEED OIL/PALM OIL AMINOPROPANEDIOL ESTERS

4.0

A gentle, semi-synthetic emollient that combines the nourishing properties of camellia and palm oils with improved stability and feel.

Irritation

low

Source

semi-synthetic

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Emollient

Camellia Kissi Seed Oil

CAMELLIA KISSI SEED OIL

4.0

A gentle, antioxidant-rich oil that hydrates and softens skin without clogging pores, suitable for most skin types.

Irritation

low

Source

natural

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Skin Conditioner

Caproyl Lysine

N-Caproyl Lysine

4.0

A mild, amino-acid-based ingredient that helps condition skin and hair without irritation.

Irritation

low

Source

semi-synthetic

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Emollient

Capryl Dimethicone

Capryl Dimethicone

4.0

A gentle silicone that makes products feel silky and spread easily without clogging pores or causing irritation.

Irritation

low

Source

synthetic

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Hair conditioning agent

Capryloyl Hydrolyzed Keratin

CAPRYLOYL HYDROLYZED KERATIN

4.0

A gentle, protein-based ingredient that helps repair and strengthen damaged hair without weighing it down.

Irritation

low

Source

semi-synthetic

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Hair Conditioner

Capryloyl Keratin Amino Acids

CAPRYLOYL KERATIN AMINO ACIDS

4.0

A mild, protein-derived ingredient that strengthens hair and soothes skin without stripping natural oils.

Irritation

low

Source

semi-synthetic

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Skin Conditioner

Capryloyl Lysine

N-CAPRYLOYL LYSINE

4.3

A mild, amino-acid-based ingredient that helps skin feel smooth and soft without clogging pores or causing irritation.

Irritation

low

Source

semi-synthetic

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Emollient

Caprylyl Trimethicone

Caprylyl Trimethicone

4.3

A gentle, lightweight silicone that makes products feel silky and helps them glide on without clogging pores.

Irritation

low

Source

synthetic

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Hair conditioning agent

Carboxymethyl Disulfide Keratin

CARBOXYMETHYL DISULFIDE KERATIN

4.0

A modified keratin protein that helps strengthen and repair hair by bonding to damaged areas, but results vary by hair type and formulation.

Irritation

low

Source

semi-synthetic

beautyhaircareprotein
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Hair Conditioner

Cassia Hydroxypropyltrimonium Chloride

Cassia Hydroxypropyltrimonium Chloride

4.3

A gentle, plant-based conditioning ingredient that makes hair smoother and easier to manage, ideal for sensitive scalps.

Irritation

low

Source

semi-synthetic

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Film Former

Castor Oil Dimer Copolymer

Bis-Isostearoyl Castor Oil/Dimer Dilinoleate Copolymer

4.0

A gentle film-forming polymer that improves wear and texture without common irritation risks.

Irritation

low

Source

semi-synthetic

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Antistatic Agent

Ceteardimonium Chloride

Ceteardimonium Chloride

3.8

Ceteardimonium Chloride is a synthetic conditioning agent that reduces static and softens hair, but it may cause irritation or clog pores in sensitive individuals.

Irritation

moderate

Source

synthetic

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Antistatic Agent

Ceteartrimonium Chloride

Ceteartrimonium Chloride

3.8

A gentle conditioning ingredient that reduces static and softens hair, but may cause mild irritation for sensitive scalps.

Irritation

moderate

Source

synthetic

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Emollient

Cetearyl Methicone

Cetearyl Methicone

4.0

A gentle silicone that smooths skin and hair without feeling heavy, making it a popular choice for lightweight formulas.

Irritation

low

Source

synthetic

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Antistatic Agent

Cetethyldimonium Bromide

Cetethyldimonium Bromide

3.5

A synthetic conditioning ingredient that helps soften hair and reduce static, but may cause irritation or clog pores in sensitive individuals.

Irritation

moderate

Source

synthetic

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Antistatic Agent

Cetrimonium Bromide

CETRIMONIUM BROMIDE

3.8

Cetrimonium bromide is an effective hair conditioner and mild preservative, but can be irritating to sensitive skin or eyes at higher concentrations.

Irritation

moderate

Source

synthetic

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Antistatic Agent

Cetrimonium Chloride

CETRIMONIUM CHLORIDE

3.8

A common conditioning ingredient that softens hair and reduces static, but can be irritating or pore-clogging for some skin types.

Irritation

moderate

Source

synthetic

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Antistatic Agent

Cetrimonium Methosulfate

CETRIMONIUM METHOSULFATE

4.0

A gentle conditioning ingredient that reduces static and softens hair without heavy buildup.

Irritation

low

Source

synthetic

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Antistatic Agent

Cetrimonium Saccharinate

CETRIMONIUM SACCHARINATE

3.8

A gentle conditioning ingredient that reduces static and improves hair manageability, but may not suit very sensitive scalps.

Irritation

low

Source

synthetic

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Antistatic Agent

Cetrimonium Tosylate

CETRIMONIUM TOSYLATE

3.8

Cetrimonium tosylate is a synthetic conditioning agent that reduces static and softens hair, but may cause mild irritation for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarehaircareconditioning agent
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Conditioning Agent

Cetyl Amodimethicone

Cetyl Amodimethicone

4.0

Cetyl Amodimethicone is a gentle silicone that adds slip and shine to hair and skin, with low irritation potential.

Irritation

low

Source

synthetic

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Surfactant

Cetyl Betaine

Cetyl Betaine

4.3

Cetyl Betaine is a gentle, coconut-derived surfactant that cleanses without stripping the skin barrier, making it ideal for sensitive skin and daily use.

Irritation

low

Source

semi-synthetic

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Emulsifier

Cetyl Dimethicone PEG-7 Acetate

Cetyl Dimethicone PEG-7 Acetate

4.0

A gentle silicone emulsifier that helps create smooth, creamy textures and leaves skin and hair feeling soft without heavy residue.

Irritation

low

Source

semi-synthetic

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Conditioning Agent

Cetyl Triethylmonium Dimethicone PEG-8 Phthalate

Cetyl Triethylmonium Dimethicone PEG-8 Phthalate

3.5

A silicone-based conditioning ingredient that helps reduce frizz and improve slip, but its complex synthetic nature and phthalate-related name may raise concerns for some users.

Irritation

low

Source

synthetic

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Film Former

Cetyl Trimethoxysilane

Cetyl Trimethoxysilane

4.0

A silicone-based film former that adds a silky feel and water resistance to products, generally well-tolerated but not a treatment ingredient.

Irritation

low

Source

synthetic

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Emulsifier

Cetyldimonium Ethyl Cetyl Phosphate

CETYLDIMONIUM ETHYL CETYL PHOSPHATE

4.0

A mild, positively charged emulsifier that helps blend ingredients and leaves skin and hair feeling soft without heavy residue.

Irritation

low

Source

semi-synthetic

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Film Former

Chitosan Hydroxypropyltrimonium Chloride

Chitosan Hydroxypropyltrimonium Chloride

4.0

A gentle, conditioning ingredient that helps hair feel soft and smooth while also offering some antimicrobial and film-forming benefits for skin.

Irritation

low

Source

semi-synthetic

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