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

Hair Conditioning Agent

Hydroxypropyltrimonium Hydrolyzed Whey

Hydroxypropyltrimonium Hydrolyzed Whey

4.0

A gentle, protein-derived conditioning ingredient that adds softness and manageability to hair without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair Conditioner

Hydroxypropyltrimonium Inulin

Hydroxypropyltrimonium Inulin

4.3

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

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair conditioning agent

Hydroxypropyltrimonium Lemon Protein

HYDROXYPROPYLTRIMONIUM LEMON PROTEIN

3.8

A gentle, plant-derived conditioning ingredient that helps detangle hair and soften skin without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair conditioning agent

Imidazolylethyl Diaminopropanamide HCl

IMIDAZOLYLETHYL DIAMINOPROPANAMIDE HCL

3.8

A synthetic hair-strengthening ingredient that helps repair damage and improve hair resilience, but research is limited to manufacturer studies.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Film Former

Inulin Lauryl Carbamate

INULIN LAURYL CARBAMATE

4.0

A gentle, plant-derived film former that leaves skin and hair feeling smooth and conditioned without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircare
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Reducing Agent

Isooctyl Thioglycolate

Isooctyl Thioglycolate

2.5

A strong chemical used to break hair bonds for perms or straightening; effective but can be irritating and requires careful handling.

Irritation

high

Source

synthetic

beautyhaircarereducing agent
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Film Former

Isophorone Diamine Copolymer

ISOPHORONE DIAMINE/ISOPHTHALIC ACID/TROMETHAMINE COPOLYMER

3.5

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

Irritation

low

Source

synthetic

beautyskincarehaircare
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Film Former

Isophoronediamine Copolymer

ISOPHORONEDIAMINE/ISOPHTHALIC ACID/PENTAERYTHRITOL COPOLYMER

3.5

A synthetic film former that helps makeup and sunscreen stay put longer, but offers no active skincare benefits.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Viscosity Controlling

Isostearamide MIPA

Isostearamide MIPA

3.8

A mild synthetic thickener and conditioner that helps products feel creamy and rinse cleanly, but offers no active skincare benefits.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Surfactant

Isostearamidopropyl Morpholine

Isostearamidopropyl Morpholine

3.5

A mild conditioning ingredient that helps reduce static and improve manageability in hair products, but is not a primary moisturizer.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Antistatic Agent

Isostearamidopropyl Morpholine Lactate

Isostearamidopropyl Morpholine Lactate

3.5

A synthetic conditioning agent that reduces static and improves feel in hair and skin products, generally well-tolerated but with limited research on long-term effects.

Irritation

low

Source

synthetic

beautyskincarehaircare
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Antistatic Agent

Isostearamidopropyl PG-Dimonium Chloride

Isostearamidopropyl PG-Dimonium Chloride

3.8

A gentle conditioning ingredient that helps hair feel soft and smooth without heavy buildup, but may not suit very fine or oily hair types.

Irritation

low

Source

synthetic

beautyskincarehaircareconditioning agent
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Antistatic Agent

Isostearaminopropalkonium Chloride

Isostearaminopropalkonium Chloride

3.5

A synthetic conditioning agent that reduces static and softens hair, but may cause irritation or clog pores in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarehaircare
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Skin conditioner

Isostearoyl Hydrolyzed Collagen

ISOSTEAROYL HYDROLYZED COLLAGEN

4.0

A gentle conditioning ingredient that helps skin and hair feel smooth and soft without being heavy.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair Conditioning Agent

Isostearoyl Hydrolyzed Silk

ISOSTEAROYL HYDROLYZED SILK

4.0

A gentle, modified silk protein that adds softness and shine to hair and skin without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircare
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Antistatic Agent

Isostearyl Benzimidonium Chloride

Isostearyl Benzimidonium Chloride

3.5

A synthetic conditioning ingredient that helps reduce static and improve hair manageability, but is less common in modern formulations.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Antistatic Agent

Isostearyl Ethyldimonium Chloride

Isostearyl Ethyldimonium Chloride

3.8

A gentle synthetic conditioner that reduces static and smooths hair without heavy buildup, suitable for most hair types.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Antistatic Agent

Isostearyl Ethylimidazolinium Ethosulfate

Isostearyl Ethylimidazolinium Ethosulfate

3.5

A synthetic antistatic ingredient that helps reduce frizz and flyaways in hair products, but it offers no long-term repair or moisturizing benefits.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Antistatic Agent

Isostearyl Laurdimonium Chloride

Isostearyl Laurdimonium Chloride

3.5

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

Irritation

moderate

Source

synthetic

beautyskincarehaircare
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Hair Conditioner

Jojoba Protein Conditioner

LAURDIMONIUM HYDROXYPROPYL HYDROLYZED JOJOBA PROTEIN

4.0

A gentle, protein-derived conditioning ingredient that helps soften hair and skin without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircare
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Soothing agent

Juazeiro Bark Extract

Ziziphus joazeiro bark extract

3.8

A gentle botanical extract from the Juazeiro tree that may help soothe the scalp and condition hair, though scientific evidence is still limited.

Irritation

low

Source

natural

beautyskincarehaircare
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Hair Conditioner

Keratin

Keratin

4.0

Keratin can temporarily smooth and strengthen hair, but results are not permanent and may not benefit all hair types.

Irritation

low

Source

natural

beautyskincarehaircare
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Hair Conditioning Agent

Keratin Amino Acid Complex

GELATIN/KERATIN AMINO ACIDS/LYSINE HYDROXYPROPYLTRIMONIUM CHLORIDE

4.0

A protein-rich conditioning complex that helps strengthen hair and reduce frizz, but may not suit very fine or low-porosity hair.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Surfactant

Keratin Amino Acid Surfactant

SODIUM/TEA-LAUROYL KERATIN AMINO ACIDS

4.0

A gentle, protein-derived surfactant that cleanses without stripping, making it a good choice for sensitive skin or damaged hair.

Irritation

low

Source

semi-synthetic

beautyskincarehaircaresurfactant
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Hair conditioning agent

Keratin Succinate Complex

CETEARAMIDOETHYLDIETHONIUM SUCCINOYL HYDROLYZED KERATIN

4.0

A modified keratin that helps repair and strengthen hair, but may not suit very fine or low-porosity hair if overused.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Emollient

Kusum Oil

Schleichera Trijuga Seed Oil

4.0

A traditional seed oil with good moisturizing potential, but limited modern research and a moderate chance of clogging pores for some skin types.

Irritation

low

Source

natural

beautyskincarehaircare
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Hair Conditioning Agent

Lauramidobutyl Guanidine Acetate

Lauramidobutyl Guanidine Acetate

3.8

A synthetic hair conditioning agent that helps soften and detangle hair, but is not widely studied for long-term effects.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Conditioning Agent

Lauramidopropyl Dimethylamine

Lauramidopropyl Dimethylamine

3.8

A mild conditioning agent that helps detangle hair and soften skin, but may cause irritation for sensitive types at high concentrations.

Irritation

moderate

Source

synthetic

beautyskincarehaircare
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Conditioning Agent

Laurdimonium Hydroxypropyl Amino Acid Complex

LAURDIMONIUM HYDROXYPROPYL (ARGININE/GLUTAMIC ACID/ISOLEUCINE/LEUCINE/LYSINE/PHENYLALANINE/PROLINE/THREONINE/VALINE)

4.0

A gentle conditioning ingredient that helps detangle hair and soften skin without heavy buildup, suitable for sensitive types.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair Conditioning Agent

Laurdimonium Hydroxypropyl Hydrolyzed Casein

LAURDIMONIUM HYDROXYPROPYL HYDROLYZED CASEIN

4.0

A gentle, protein-based conditioning ingredient that helps smooth hair and lightly moisturize skin without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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