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 569
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

Capryloyl Hydrolyzed Collagen

CAPRYLOYL HYDROLYZED COLLAGEN

4.0

A gentle, modified collagen that helps hydrate and smooth skin without the stickiness of plain collagen.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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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

beautyhaircareconditioning agent
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Skin Conditioning Agent

Caprylyl Pyrrolidone

Caprylyl Pyrrolidone

4.0

Caprylyl Pyrrolidone is a gentle synthetic ingredient that helps other active ingredients absorb better while leaving skin feeling soft and smooth.

Irritation

low

Source

synthetic

beautyskincareconditioning agent
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Skin conditioning agent

Carnitine Tartrate

CARNITINE TARTRATE

4.0

Carnitine Tartrate is a gentle, multi-tasking ingredient that helps balance oil production, supports skin barrier health, and offers antioxidant protection.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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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

beautyhaircareconditioning agent
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Skin conditioning agent

Caviar Extract

CAVIAR EXTRACT

3.5

Caviar extract is a nutrient-rich ingredient that may help hydrate and condition skin, but its benefits are largely anecdotal and backed by limited clinical research.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Antistatic Agent

Cetealkonium Bromide

CETEARALKONIUM BROMIDE

3.5

Cetealkonium bromide is an effective conditioning and antimicrobial ingredient, but it can be irritating for sensitive skin and is best used in rinse-off formulas.

Irritation

moderate

Source

synthetic

beautyskincareconditioning agent
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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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Skin conditioning agent

Cholecalciferol PEG-12 Ether

CHOLECALCIFEROL PEG-12 ETHER

3.5

A PEG-modified form of vitamin D3 that may support skin barrier function, but research is limited and the ingredient is uncommon in mainstream products.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Skin conditioning agent

Chryseobacterium Ferment Filtrate

CHRYSEOBACTERIUM SP. MK-8 FERMENT FILTRATE

3.8

A gentle, biotech-derived ferment that may help calm and condition skin, but research is still early.

Irritation

low

Source

biotech

beautyskincareconditioning agent
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Antistatic Agent

Cinnamidopropyltrimonium Chloride

CINNAMIDOPROPYLTRIMONIUM CHLORIDE

3.8

A gentle conditioning ingredient that helps smooth hair and reduce static, with a mild cinnamon-derived scent.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Conditioning Agent

Coco Glucoside Derivative Conditioner

Laurdimoniumhydroxypropyl Coco-Glucosides Chloride

4.0

A gentle, plant-derived conditioning ingredient that makes hair feel softer and reduces frizz without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Antistatic Agent

Coco-Ethyldimonium Ethosulfate

Coco-Ethyldimonium Ethosulfate

4.0

A gentle, coconut-derived conditioner that helps reduce static and soften hair without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Antistatic Agent

Cocodimonium Epoxypropyl Chloride

2,3-EPOXYPROPYL COCODIMONIUM CHLORIDE

3.5

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

Irritation

moderate

Source

synthetic

beautyhair careconditioning agent
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Hair Conditioning Agent

Cocodimonium Hydroxypropyl Hydrolyzed Casein

Cocodimonium Hydroxypropyl Hydrolyzed Casein

3.8

A gentle conditioning protein that helps hair feel softer and more manageable, but may not suit protein-sensitive hair types.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Antistatic Agent

Cocotrimonium Chloride

Cocotrimonium Chloride

4.0

A gentle, coconut-derived conditioner that reduces static and softens hair without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Film Former

Cocoyl Hydrolyzed Elastin

Cocoyl Hydrolyzed Elastin

3.8

A mild, protein-based conditioning ingredient that temporarily smooths hair and softens skin without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair Conditioner

Cocoyl Hydrolyzed Keratin

COCOYL HYDROLYZED KERATIN

4.0

Cocoyl hydrolyzed keratin is a gentle, protein-rich conditioner that helps strengthen and smooth hair without weighing it down.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Conditioning Agent

Colostrum

Colostrum

3.8

Colostrum is a nutrient-rich ingredient that may help soothe and condition the skin, but research on its cosmetic benefits is still limited.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Conditioning Agent

Colostrum Extract

SINE ADIPE COLOSTRUM

3.5

Colostrum extract is a gentle, nutrient-dense ingredient that may support skin hydration and barrier comfort, but research is still emerging.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Skin conditioning agent

Cytosine

CYTOSINE

3.5

Cytosine is a DNA building block with emerging research in skincare, but its benefits are not yet well-established for topical use.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Eyelash enhancer

Dechloro Ethylcloprostenolamide

DECHLORO ETHYLCLOPROSTENOLAMIDE

2.5

A synthetic ingredient that may boost eyelash growth but carries significant irritation and safety concerns, including potential eye and skin reactions.

Irritation

high

Source

synthetic

beautyskincareconditioning agent
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Skin conditioning agent

Decyloxyacetaldehyde

DECYLOXYACETALDEHYDE

3.5

Decyloxyacetaldehyde is a synthetic ingredient that may help improve skin texture, but research is limited and it can be irritating for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincareconditioning agent
Read ingredient review

Conditioning agent

Deer Blood Extract

Cervus Elaphus Blood Extract

2.5

Deer blood extract is a niche ingredient with traditional use but minimal modern research to support its cosmetic benefits.

Irritation

moderate

Source

natural

beautyskincareconditioning agent
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Skin conditioning

Defatted Egg Yolk Powder

DEFATTED EGG YOLK POWDER

3.5

A protein-rich powder that can help condition skin and hair, but its benefits are not well-studied in modern cosmetics.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Skin conditioning agent

Defined Cell Culture Media 14

Defined Cell Culture Media 14

3.5

A biotech ingredient that provides a complex blend of nutrients to support skin cell function, but its benefits in finished products are still being studied.

Irritation

low

Source

biotech

beautyskincareconditioning agent
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Skin conditioning agent

Diacetyl Benzoyl Lathyrol

DIACETYL BENZOYL LATHYROL

3.5

An emerging semi-synthetic ingredient that may help support skin barrier function, but research is still limited.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Antistatic Agent

Dibehenoylethyl Dimonium Chloride

Dibehenoylethyl Dimonium Chloride

4.0

A mild, plant-derived conditioning ingredient that smooths hair without heavy buildup, suitable for fine or sensitive hair.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Antistatic Agent

Dibehenyldimonium Chloride

Dibehenyldimonium Chloride

4.0

A gentle, effective conditioning ingredient that reduces static and improves manageability without heavy buildup.

Irritation

low

Source

synthetic

beautyskincarehaircareconditioning agent
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Antistatic Agent

Dicetyldimonium Chloride

Dicetyldimonium Chloride

3.8

A gentle synthetic conditioner that reduces static and softens hair without heavy buildup, but may not suit very fine or oily hair types.

Irritation

low

Source

synthetic

beautyskincarehaircareconditioning agent
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Skin conditioning agent

Diethyl Aspartate

DIETHYL ASPARTATE

3.5

Diethyl Aspartate is a gentle synthetic ingredient that helps skin feel smooth and conditioned, but research on its long-term benefits is still limited.

Irritation

low

Source

synthetic

beautyskincareconditioning agent
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Conditioning Agent

Diethylaminoethyl Stearate

DIETHYLAMINOETHYL STEARATE

3.5

A synthetic conditioning agent that can improve texture but may be irritating or clog pores for some skin types.

Irritation

moderate

Source

synthetic

beautyskincareconditioning agent
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Skin conditioning agent

Diglycol Guanidine Succinate

DIGLYCOL GUANIDINE SUCCINATE

3.5

Diglycol Guanidine Succinate is a synthetic conditioning agent that helps improve the feel and mildness of skincare and haircare products, but research on its long-term effects is limited.

Irritation

low

Source

synthetic

beautyskincareconditioning agent
Read ingredient review