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 1,375
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

Antistatic Agent

Ditallowdimonium Chloride

Ditallowdimonium Chloride

3.5

Ditallowdimonium Chloride is an effective hair conditioner and antistatic agent, but it may cause irritation or clog pores in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarehaircare
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Antistatic Agent

Ditallowoyl PG-Dimonium Chloride

Ditallowoyl PG-Dimonium Chloride

3.5

An effective hair-softening ingredient from animal-derived tallow, but may be too heavy for oily or acne-prone skin.

Irritation

low

Source

semi-synthetic

beautyskincarehaircare
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Antistatic Agent

Ditridecyldimonium Chloride

Ditridecyldimonium Chloride

3.5

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

Irritation

moderate

Source

synthetic

beautyhaircareconditioning agent
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Film Former

DMAPA Acrylates Copolymer

DMAPA ACRYLATES/ACRYLIC ACID/ACRYLONITROGENS COPOLYMER

3.5

A synthetic polymer that helps products stay put and resist water, but offers no active skincare benefit.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Film Former

DMPA/PPG-36/SMDI Copolymer

DMPA/PPG-36/SMDI Copolymer

3.8

A synthetic polymer that helps products stay put and resist water, but may feel heavy on some skin types.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Antistatic Agent

Dodecylhexadecyltrimonium Chloride

Dodecylhexadecyltrimonium Chloride

3.5

A synthetic conditioning agent that reduces static and softens hair, but may be irritating or pore-clogging for some skin types.

Irritation

moderate

Source

synthetic

beautyskincarehaircare
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Antistatic Agent

Dodecylxylylditrimonium Chloride

Dodecylxylylditrimonium Chloride

3.5

An effective synthetic conditioning agent that reduces static and improves manageability, but may cause irritation for sensitive scalps.

Irritation

moderate

Source

synthetic

beautyskincarehaircare
Read ingredient review

Soothing Agent

Eclipta Prostrata Leaf Oil

ECLIPTA PROSTRATA LEAF OIL

3.8

Eclipta Prostrata Leaf Oil is a gentle, antioxidant-rich botanical oil that may help soothe the scalp and support healthy-looking hair, but more human studies are needed to confirm its benefits.

Irritation

low

Source

natural

beautyskincarehaircare
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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

Ethalkonium Chloride Acrylate Copolymer

ETHALKONIUM CHLORIDE ACRYLATE/HEMA/STYRENE COPOLYMER

3.5

A synthetic polymer that helps products form a flexible, long-lasting film on hair or skin, but offers no active skincare benefits.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Reducing Agent

Ethanolamine Dithiodiglycolate

ETHANOLAMINE DITHIODIGLYCOLATE

3.5

A potent reducing agent for hair restructuring, but requires careful formulation and professional handling to minimize scalp irritation.

Irritation

moderate

Source

synthetic

beautyhaircarereducing agent
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Film Former

Ethyl Ester of Hydrolyzed Animal Protein

ETHYL ESTER OF HYDROLYZED ANIMAL PROTEIN

3.5

A gentle conditioning protein that can temporarily smooth hair and skin, but its animal origin and limited long-term benefits may not suit everyone.

Irritation

low

Source

natural

beautyskincarehaircare
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Film-Forming Agent

Ethyl Ester of Hydrolyzed Keratin

ETHYL ESTER OF HYDROLYZED KERATIN

4.0

A gentle, modified keratin protein that forms a protective film on hair and skin to improve strength, moisture retention, and manageability.

Irritation

low

Source

semi-synthetic

beautyskincarehaircarefilm-forming agent
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Film Former

Ethyl Polysilicate

Ethyl Polysilicate

3.8

A synthetic film-former that helps makeup and sunscreen stay put, but may feel slightly tight on very dry skin.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Film Former

Ethyl Polysilsesquioxane

Ethyl Polysilsesquioxane

4.0

A gentle silicone that forms a breathable, water-resistant film for a smooth, silky feel without clogging pores.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Emollient

Ethyl Trisiloxane

ETHYL TRISILOXANE

4.0

A lightweight silicone that helps products glide on smoothly and leaves a silky finish without clogging pores.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Film Former

Ethylcellulose

Ethylcellulose

4.0

A gentle film-former that helps products spread smoothly and stay put without clogging pores.

Irritation

low

Source

semi-synthetic

beautyskincarehaircare
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Optical Brightener

Fluorescent Brightener 393

Fluorescent Brightener 393

2.5

A synthetic optical brightener that makes skin and hair appear brighter by reflecting blue light, but it offers no real skincare benefit and may cause sensitivity in some.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Film Former

Fluorinated Film-Forming Copolymer

ISOBUTYL METHACRYLATE/TRIFLUOROETHYLMETHACRYLATE/BIS-HYDROXYPROPYL DIMETHICONE ACRYLATE COPOLYMER

3.5

A high-performance film former that helps products stay put, but its fluorinated chemistry raises environmental persistence concerns.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Film Former

Fluoro-Film Forming Polymer

ACRYLATES/TRIFLUOROPROPYLMETHACRYLATE/POLYTRIMETHYL SILOXYMETHACRYLATE COPOLYMER

3.5

A synthetic polymer that helps products stay put and resist water, but offers no active skincare benefit.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Anti-androgen

Fluridil

Fluridil

3.5

Fluridil is a synthetic anti-androgen applied to the scalp to help slow hair thinning, but its effectiveness and long-term safety are not as well-established as some alternatives.

Irritation

low

Source

synthetic

beautyhaircareanti-androgen
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Film Former

Fumaric Acid Copolymer

FUMARIC ACID/PHTHALIC ANHYDRIDE/TRICYCLODECANEDIMETHANOL COPOLYMER

3.5

A synthetic film-former that helps products stay put, but offers no active skincare benefits.

Irritation

low

Source

synthetic

beautyskincarehaircare
Read ingredient review

Film Former

Gelatin Lysine Polyacrylamide Complex

GELATIN/LYSINE/POLYACRYLAMIDE HYDROXYPROPYLTRIMONIUM CHLORIDE

3.8

A conditioning polymer blend that helps hair and skin feel smooth and soft, but its synthetic nature and limited research may give some users pause.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Antistatic Agent

Ginseng Hydroxypropyltrimonium Chloride

Ginseng Hydroxypropyltrimonium Chloride

4.0

A gentle conditioning ingredient that helps reduce static and improve softness in hair and skin products, with added antioxidant benefits from ginseng.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Film Former

Gluconamido Amodimethicone

Gluconamido Amodimethicone

4.0

A gentle, modified silicone that smooths hair and skin without heavy buildup, making it a good choice for fine or oily hair types.

Irritation

low

Source

synthetic

beautyskincarehaircareconditioning agent
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Film Former

Glycerin/Phthalic Acid Copolymer Castorate

GLYCERIN/PHTHALIC ACID COPOLYMER CASTORATE

3.8

A film-forming polymer that helps products stay put and resist water, but its phthalic acid component raises mild safety questions despite being bound in a polymer.

Irritation

low

Source

semi-synthetic

beautyskincarehaircare
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Reducing agent

Glyceryl Thioglycolate

GLYCERYL THIOGLYCOLATE

3.0

A strong chemical used to break and reform hair bonds for perms or straightening; not for everyday use and requires professional handling.

Irritation

high

Source

synthetic

beautyhaircarereducing agent
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Film Former

Glycidoxy Dimethicone

GLYCIDOXY DIMETHICONE

3.5

A reactive silicone that helps products spread smoothly and form a flexible film, but its epoxy group raises some formulation and safety considerations.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Hair straightening agent

Glyoxyloyl Cysteine

GLYOXYLOYL CYSTEINE

3.8

A gentler alternative to harsh hair straighteners that works by temporarily reshaping hair bonds without breaking them.

Irritation

low

Source

semi-synthetic

beautyhaircarehair conditioner
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Hair conditioning agent

Glyoxyloyl Keratin Amino Acids

GLYOXYLOYL KERATIN AMINO ACIDS

4.0

A gentle keratin-derived ingredient that helps smooth and strengthen hair without harsh chemicals, ideal for those seeking a milder alternative to traditional straightening treatments.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Hair Conditioning Agent

Grapeseed-Derived Conditioning Agent

SODIUM GRAPESEEDAMIDOPROPYL PG-DIMONIUM CHLORIDE PHOSPHATE

3.8

A gentle conditioning ingredient derived from grapeseed oil that helps soften hair and reduce static without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircare
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Surfactant

Guanidine Surfactant Blend

Laur/myrist/palmitamidobutyl guanidine acetate

3.5

A gentle synthetic conditioning agent that helps detangle and soften hair without heavy buildup.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Antistatic Agent

Guar Hydroxypropyltrimonium Chloride

GUAR HYDROXYPROPYLTRIMONIUM CHLORIDE

4.0

A gentle, plant-derived conditioning ingredient that makes hair softer and less frizzy without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Colorant

HC Blue No. 15

HC Blue No. 15

3.5

HC Blue No. 15 is a synthetic hair dye that can deliver vibrant blue shades but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhaircarecolorant
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Hair Colorant

HC Orange No. 2

HC Orange No. 2

3.5

HC Orange No. 2 is a synthetic dye that adds orange shades to hair color, but it may cause irritation in sensitive individuals and has limited long-term safety data.

Irritation

moderate

Source

synthetic

beautyhaircarecolorant
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Hair Colorant

HC Red No. 18

HC RED NO. 18

3.5

HC Red No. 18 is a synthetic colorant for hair dyes that can cause irritation in sensitive individuals, but is generally considered safe for use in rinse-off products.

Irritation

moderate

Source

synthetic

beautyhaircarecolorant
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Hair Colorant

HC Red No. 3

HC RED NO. 3

3.5

HC Red No. 3 is a widely used synthetic hair dye colorant, but it may cause skin irritation in sensitive individuals and has limited long-term safety data.

Irritation

moderate

Source

synthetic

beautyhaircarecolorant
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Hair Colorant

HC Red No. 7

HC Red No. 7

3.5

HC Red No. 7 is a synthetic colorant for hair dyes that can cause irritation in sensitive individuals, especially with frequent use.

Irritation

moderate

Source

synthetic

beautyhaircarecolorant
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Hair Colorant

HC Yellow No. 10

HC YELLOW NO. 10

3.5

HC Yellow No. 10 is a common synthetic hair dye that adds yellow shades but may cause irritation for sensitive scalps.

Irritation

moderate

Source

synthetic

beautyhaircarecolorant
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