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 20,769
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

Antioxidant

Dihydroxy Dimethyl Pyridine

2,6-DIHYDROXY-3,4-DIMETHYLPYRIDINE

3.5

A synthetic antioxidant that may help protect skin from environmental stress, but research is still limited.

Irritation

low

Source

synthetic

beautyskincareantioxidant
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Antioxidant

Dihydroxy Methylchromonyl Palmitate

Dihydroxy Methylchromonyl Palmitate

4.0

A synthetic antioxidant that helps shield skin from pollution and UV damage while supporting a brighter, more even complexion.

Irritation

low

Source

synthetic

beautyskincareantioxidant
Read ingredient review

Colorant

Dihydroxyacetone

DIHYDROXYACETONE

4.0

DHA is the gold standard for sunless tanning, providing a natural-looking tan without UV exposure, but requires careful application to avoid streaks and uneven color.

Irritation

low

Source

synthetic

beautyskincarecolorant
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Self-tanning agent

Dihydroxyacetone (DHA)

Dihydroxyacetone

4.0

DHA is the most common active ingredient in sunless tanners, providing a temporary tan without UV exposure.

Irritation

low

Source

synthetic

beautyskincareself-tanner
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Skin brightening agent

Dihydroxybenzylidine Thiazolidinedione

Dihydroxybenzylidine Thiazolidinedione

3.5

A synthetic brightening compound with early evidence for reducing pigmentation, but limited long-term safety data.

Irritation

moderate

Source

synthetic

beautyskincarebrightening agent
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Antioxidant

Dihydroxydimethoxychalcone

Dihydroxydimethoxychalcone

4.0

A gentle antioxidant from the chalcone family that may help calm skin and defend against pollution and UV damage.

Irritation

low

Source

natural

beautyskincareantioxidant
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Surfactant

Dihydroxyethyl Cocoamine Oxide

DIHYDROXYETHYL COCAMINE OXIDE

4.0

A gentle, coconut-derived surfactant that helps create a rich lather while being less stripping than traditional sulfates.

Irritation

low

Source

natural

beautyskincaresurfactant
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Surfactant

Dihydroxyethyl Lauramine Oxide

Dihydroxyethyl Lauramine Oxide

4.0

A gentle, coconut-derived surfactant that boosts foam and cleanses without stripping the skin, making it a good choice for sensitive skin.

Irritation

low

Source

semi-synthetic

beautyskincarecleansing
Read ingredient review

Surfactant

Dihydroxyethyl Oleyl Glycinate

Dihydroxyethyl Oleyl Glycinate

4.0

A gentle, amino-acid-based surfactant that cleanses effectively without stripping the skin, making it a great choice for sensitive or dry skin types.

Irritation

low

Source

semi-synthetic

beautyskincarecleanser
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Emulsifier

Dihydroxyethyl Soyamine Dioleate

Dihydroxyethyl Soyamine Dioleate

3.8

A gentle emulsifier and conditioner from soybean oil that helps blend oils and water while softening hair and skin, but may be too heavy for oily or acne-prone types.

Irritation

low

Source

semi-synthetic

beautyskincarehaircare
Read ingredient review

Surfactant

Dihydroxyethyl Tallow Glycinate

Dihydroxyethyl Tallow Glycinate

3.5

A mild, tallow-derived surfactant that cleanses without stripping, but may raise concerns for those avoiding animal-derived ingredients.

Irritation

low

Source

semi-synthetic

beautyskincarecleansing agent
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Surfactant

Dihydroxyethyl Tallowamine HCl

Dihydroxyethyl Tallowamine HCl

3.0

An effective cleanser and antistatic agent from tallow, but may be drying or irritating for sensitive skin.

Irritation

moderate

Source

semi-synthetic

beautyskincaresurfactant
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Surfactant

Dihydroxyethyl Tallowamine Oxide

DIHYDROXYETHYL TALLOWAMINE OXIDE

3.5

An effective foam booster and surfactant, but may cause irritation for sensitive skin and raises ethical concerns due to its animal-derived origin.

Irritation

moderate

Source

semi-synthetic

beautyskincarecleansing
Read ingredient review

Colorant

Dihydroxyethylaminotoluene

2,6-Dihydroxyethylaminotoluene

3.0

A synthetic dye ingredient used in permanent hair color; it can be effective but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
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Pigment Modulator

Dihydroxyindole

DIHYDROXYINDOLE

3.5

Dihydroxyindole is a natural melanin precursor that may help enhance pigmentation and provide antioxidant benefits, but its cosmetic use is still emerging and not widely studied in humans.

Irritation

low

Source

natural

beautyskincarehair care
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Oxidative dye precursor

Dihydroxyindoline HBr

DIHYDROXYINDOLINE HBR

3.5

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

Irritation

moderate

Source

synthetic

beautyhair coloroxidative dye precursor
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Surfactant

Dihydroxyisopropyl Palmoylpalmamide

DIHYDROXYISOPROPYL PALMOYLPALMAMIDE

3.5

A mild synthetic surfactant that helps create rich foam and improve cleansing texture, generally well-tolerated by most skin types.

Irritation

low

Source

synthetic

beautyskincaresurfactant
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Antioxidant

Dihydroxymethoxy Dihydrochalcone

Dihydroxymethoxy Dihydrochalcone

4.0

A gentle synthetic antioxidant that helps brighten skin and fight signs of aging, with a good safety profile for most skin types.

Irritation

low

Source

synthetic

beautyskincareantioxidant
Read ingredient review

Humectant

Dihydroxypropyl Arginine HCl

DIHYDROXYPROPYL ARGININE HCL

4.0

A gentle, water-loving amino acid derivative that helps attract moisture to the skin and may support a healthier barrier.

Irritation

low

Source

semi-synthetic

beautyskincarehumectant
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Hair conditioning agent

Dihydroxypropyl Cystine

DIHYDROXYPROPYL CYSTINE

4.0

A gentle amino acid derivative that helps reinforce hair structure, making strands feel stronger and less prone to breakage.

Irritation

low

Source

semi-synthetic

beautyskincarehair care
Read ingredient review

Eyelash growth stimulant

Dihydroxypropyl Didehydrolatanoprostamide

DIHYDROXYPROPYL DIDEHYDROLATANOPROSTAMIDE

3.5

A synthetic prostaglandin analog that can enhance eyelash and brow growth but carries risks of irritation and potential eye-area side effects.

Irritation

moderate

Source

synthetic

beautyskincarelash-and-brow
Read ingredient review

Film Former

Dihydroxypropyl Hydrolyzed Casein

DIHYDROXYPROPYL HYDROLYZED CASEIN

3.8

A gentle, modified milk protein that forms a protective film on hair and skin to lock in moisture and smooth texture.

Irritation

low

Source

semi-synthetic

beautyskincarefilm-former
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Surfactant

Dihydroxypropyl N-Methyllauramide

DIHYDROXYPROPYL N-METHYLLAURAMIDE

4.0

A gentle, low-irritation surfactant that helps create a rich lather and improve cleansing without stripping the skin.

Irritation

low

Source

semi-synthetic

beautyskincaresurfactant
Read ingredient review

Antistatic Agent

Dihydroxypropyltrimonium Chloride

DIHYDROXYPROPYLTRIMONIUM CHLORIDE

4.0

A gentle antistatic and conditioning ingredient that helps reduce flyaways and improve hair feel without heavy buildup.

Irritation

low

Source

synthetic

beautyskincarehaircare
Read ingredient review

Preservative

Diiodomethyltolylsulfone

DIIODOMETHYLTOLYLSULFONE

3.5

An effective preservative but can be a skin sensitizer, so it's best suited for rinse-off products or low concentrations.

Irritation

moderate

Source

synthetic

beautyskincarepreservative
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Emollient

Diisoamyl Malate

Diisoamyl Malate

4.0

A silky, non-greasy emollient that feels lightweight on skin and helps other ingredients spread evenly.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Emollient

Diisoamyl Sebacate

Diisoamyl Sebacate

4.0

A silky, non-greasy emollient that softens skin without clogging pores, ideal for lightweight formulas.

Irritation

low

Source

natural

beautyskincareemollient
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Emollient

Diisobutyl Adipate

DIISOBUTYL ADIPATE

3.8

A lightweight synthetic emollient that helps products spread smoothly without a greasy feel, generally considered safe for most skin types.

Irritation

low

Source

synthetic

beautyskincareemollient
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Emollient

Diisobutyl Glutarate

DIISOBUTYL GLUTARATE

4.0

A lightweight, non-greasy emollient that helps products spread smoothly and leaves skin feeling soft without clogging pores.

Irritation

low

Source

synthetic

beautyskincareemollient
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Solvent

Diisobutyl Ketone

2,6-DIMETHYL-4-HEPTANONE

2.5

A synthetic solvent used mainly in fragrances; not a primary skincare active and may cause irritation at higher levels.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Emollient

Diisobutyl Maleate

Diisobutyl Maleate

3.8

A lightweight synthetic emollient that helps products spread smoothly and leaves skin feeling soft without greasiness.

Irritation

low

Source

synthetic

beautyskincareemollient
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Solvent

Diisobutyl Oxalate

DIISOBUTYL OXALATE

3.5

Diisobutyl Oxalate is a synthetic solvent that helps dissolve other ingredients and creates a silky feel, but it has limited research on long-term skin effects.

Irritation

low

Source

synthetic

beautyskincaresolvent
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Surfactant

Diisobutyl Sodium Sulfosuccinate

DIISOBUTYL SODIUM SULFOSUCCINATE

3.8

A strong synthetic cleanser that effectively removes oil and dirt but may be drying or irritating for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarecleanser
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Emollient

Diisobutyl Succinate

Diisobutyl Succinate

4.0

A lightweight, non-greasy emollient that helps products glide on smoothly without clogging pores.

Irritation

low

Source

synthetic

beautyskincareemollient
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Emollient

Diisocetyl Adipate

Diisocetyl Adipate

4.0

A lightweight synthetic oil that softens skin without clogging pores, commonly used to improve product texture.

Irritation

low

Source

synthetic

beautyskincareemollient
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Emollient

Diisodecyl Adipate

DIISODECYL ADIPATE

4.3

A lightweight synthetic emollient that softens skin without clogging pores, commonly used to improve product texture and spreadability.

Irritation

low

Source

synthetic

beautyskincareemollient
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Plasticizer

Diisodecyl Phthalate

Diisodecyl Phthalate

1.0

Diisodecyl phthalate is a plasticizer with limited cosmetic use; it is not a typical skincare ingredient and is best avoided due to potential health concerns.

Irritation

low

Source

synthetic

beautyskincareplasticizer
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Plasticizer

Diisoheptyl Phthalate

Diisoheptyl Phthalate

1.0

Diisoheptyl Phthalate is a synthetic plasticizer with no proven skincare benefit and potential health concerns; it is best avoided in leave-on products.

Irritation

moderate

Source

synthetic

beautyskincareplasticizer
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