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 23 of 83
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 colorant

Hydroxyethylaminoanisole

2-AMINO-4-HYDROXYETHYLAMINOANISOLE

3.0

A synthetic yellow dye for hair color, generally considered safe in regulated concentrations but can cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair colorant

Hydroxyethylaminoanisole Sulfate

2-AMINO-4-HYDROXYETHYLAMINOANISOLE SULFATE

3.0

A synthetic dye used in hair color that can cause irritation in sensitive individuals but is generally considered safe in regulated concentrations.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Colorant

Hydroxyethylaminophenol

2-METHYL-5-HYDROXYETHYLAMINOPHENOL

3.5

A synthetic colorant used in hair dyes; generally safe when used as directed but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorcolorant
Read ingredient review

Hair colorant

Hydroxypropylamino Nitrophenol

4-HYDROXYPROPYLAMINO-3-NITROPHENOL

3.5

A synthetic violet dye for hair color, generally safe in rinse-off formulas but may cause irritation for sensitive scalps.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair colorant

Isopropyl Diamino Pyrazole Sulfate

N-ISOPROPYL 4,5-DIAMINO PYRAZOLE SULFATE

3.5

A synthetic hair dye ingredient that helps create vibrant, lasting color but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colordye precursor
Read ingredient review

Hair Dye Intermediate

M-Aminophenol

M-AMINOPHENOL

3.0

M-Aminophenol is a synthetic dye ingredient used in hair color to achieve cool, ashy tones, but it can be a skin irritant and allergen for some people.

Irritation

moderate

Source

synthetic

beautyhair colordye intermediate
Read ingredient review

Hair colorant

M-Aminophenol HCl

M-AMINOPHENOL HCL

2.5

M-Aminophenol HCl is a synthetic dye ingredient used in permanent hair color to create cool, ashy shades, but it can be a skin irritant for some people.

Irritation

moderate

Source

synthetic

beautyhair colorcolorant
Read ingredient review

Hair dye intermediate

Methylenebis Aminophenol

2,2'-METHYLENEBIS-4-AMINOPHENOL

3.0

A synthetic hair dye intermediate that helps create long-lasting color but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic
Read ingredient review

Colorant

Methylenebis Aminophenol HCl

2,2'-METHYLENEBIS-4-AMINOPHENOL HCL

3.5

A synthetic hair dye intermediate that helps create long-lasting color but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic
Read ingredient review

Hair colorant intermediate

N-Phenyl-p-Phenylenediamine

N-PHENYL-P-PHENYLENEDIAMINE

2.0

A strong hair dye intermediate that can cause allergic reactions and skin irritation; not recommended for sensitive individuals.

Irritation

high

Source

synthetic

beautyhair colorchemical intermediate
Read ingredient review

Hair colorant

N-Phenyl-p-Phenylenediamine Sulfate

N-PHENYL-P-PHENYLENEDIAMINE SULFATE

2.5

A common but potent hair dye ingredient that can cause allergic reactions and skin irritation; use with caution and always patch test.

Irritation

high

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair Dye Intermediate

O-Aminophenol

O-AMINOPHENOL

2.5

O-Aminophenol is a synthetic hair dye intermediate that helps create specific colors but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorchemical intermediate
Read ingredient review

Hair colorant

O-Aminophenol Sulfate

O-AMINOPHENOL SULFATE

3.5

A synthetic hair dye ingredient that creates warm shades but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair coloroxidative dye
Read ingredient review

Colorant

P-Aminophenol

P-AMINOPHENOL

2.5

P-Aminophenol is a common hair dye ingredient that helps create natural-looking shades, but it can cause allergic reactions and irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorchemical
Read ingredient review

Colorant

P-Aminophenol Sulfate

P-AMINOPHENOL SULFATE

2.0

A synthetic hair dye ingredient that helps create long-lasting color but can cause skin irritation and allergic reactions in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorchemical
Read ingredient review

Hair colorant

P-Phenylenediamine Sulfate

P-PHENYLENEDIAMINE SULFATE

2.0

A powerful but potentially irritating hair dye ingredient that requires careful patch testing before use.

Irritation

high

Source

synthetic

beautyhair colorsynthetic
Read ingredient review

Hair colorant

PEG-3 2,2'-Di-p-phenylenediamine

PEG-3 2,2'-Di-p-phenylenediamine

3.0

A synthetic hair dye ingredient that helps color develop and last, but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic
Read ingredient review

Colorant

Picramic Acid

PICRAMIC ACID

2.5

Picramic acid is a synthetic dye used in hair color, but it has limited safety data and potential for skin irritation, making it a less common choice in modern formulations.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Colorant

Sodium Picramate

SODIUM PICRAMATE

2.5

Sodium Picramate is a synthetic dye used in hair color, but it can be a skin sensitizer and is best avoided by those with sensitive scalps.

Irritation

moderate

Source

synthetic

beautyhair colordye
Read ingredient review

Hair colorant

Toluene-2,5-Diamine

TOLUENE-2,5-DIAMINE

3.0

A common hair dye ingredient that delivers long-lasting color but can cause skin irritation and allergic reactions in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic
Read ingredient review