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

Hair colorant

HC Orange No. 6

HC Orange No. 6

3.5

HC Orange No. 6 is a synthetic dye that adds orange tones to hair color, but it may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair colorant

HC Red 18

2,6-DIAMINO-3-((PYRIDIN-3-YL)AZO)PYRIDINE

3.5

HC Red 18 is a synthetic dye that adds red shades to hair color, but it may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Colorant

HC Red No. 1

HC RED NO. 1

3.0

HC Red No. 1 is a synthetic hair dye that adds red tones but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair Colorant

HC Red No. 10

HC Red No. 10

3.5

HC Red No. 10 is a synthetic dye used in hair color products; it is generally considered safe for external use but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair colorant

HC Red No. 11

HC Red No. 11

3.5

HC Red No. 11 is a synthetic hair dye that adds red tones but may cause irritation in sensitive individuals or with frequent use.

Irritation

moderate

Source

synthetic

beautyhair colordye
Read ingredient review

Colorant

HC Red No. 13

HC RED NO. 13

3.5

A synthetic red hair dye that can deliver vibrant color but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair colorant

HC Red No. 14

HC RED NO. 14

3.5

HC Red No. 14 is a synthetic dye used in hair color products; it is generally considered safe for use on hair but may cause irritation for sensitive scalps.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair Colorant

HC Red No. 15

HC RED NO. 15

3.0

HC Red No. 15 is a synthetic dye for red hair color, but it may cause irritation in sensitive individuals and has limited safety data for long-term use.

Irritation

moderate

Source

synthetic

beautyhair-carecolorant
Read ingredient review

Hair Colorant

HC Red No. 17

HC RED NO. 17

3.5

HC Red No. 17 is a synthetic hair dye that adds red tones but may cause scalp irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair carecolorant
Read ingredient review

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
Read ingredient review

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
Read ingredient review

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
Read ingredient review

Hair Colorant

HC Violet No. 1

HC Violet No. 1

3.5

HC Violet No. 1 is a synthetic dye that adds violet tones to hair, commonly used to neutralize brassiness or create cool shades, but it may cause mild irritation in sensitive individuals.

Irritation

low

Source

synthetic

beautyhair carecolorant
Read ingredient review

Hair colorant

HC Violet No. 2

HC Violet No. 2

3.5

HC Violet No. 2 is a synthetic hair dye that adds violet tones but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

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
Read ingredient review

Colorant

HC Yellow No. 13

HC Yellow No. 13

3.5

HC Yellow No. 13 is a synthetic colorant used in hair dyes, generally considered safe in rinse-off products but may cause irritation for sensitive scalps.

Irritation

moderate

Source

synthetic

beautyhair carecolorant
Read ingredient review

Hair Colorant

HC Yellow No. 14

HC Yellow No. 14

3.5

HC Yellow No. 14 is a synthetic yellow dye for hair color, generally considered safe in regulated concentrations but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhaircarecolorant
Read ingredient review

Hair Colorant

HC Yellow No. 15

HC YELLOW NO. 15

3.5

HC Yellow No. 15 is a synthetic yellow dye for hair color, generally considered safe in rinse-off products but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair carecolorant
Read ingredient review

Hair Colorant

HC Yellow No. 16

HC Yellow No. 16

3.5

HC Yellow No. 16 is a synthetic colorant used in hair dyes, generally considered safe in regulated concentrations but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair carecolorant
Read ingredient review

Colorant

HC Yellow No. 17

HC Yellow No. 17

3.5

HC Yellow No. 17 is a synthetic yellow dye for hair color that is generally considered safe in rinse-off products but may cause irritation for sensitive scalps.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair colorant

HC Yellow No. 2

HC YELLOW NO. 2

3.5

HC Yellow No. 2 is a synthetic dye that adds yellow tones to hair color, but it may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair colorant

HC Yellow No. 4

HC YELLOW NO. 4

3.5

HC Yellow No. 4 is a synthetic hair dye that adds yellow shades to hair color products, but it may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Colorant

HC Yellow No. 7

HC Yellow No. 7

3.5

HC Yellow No. 7 is a synthetic hair dye that can provide vibrant yellow shades, but it may cause irritation in sensitive individuals and is not intended for skin or eyelash use.

Irritation

moderate

Source

synthetic

beautyhair colorsynthetic dye
Read ingredient review

Hair Colorant

HC Yellow No. 9

HC YELLOW NO. 9

3.5

HC Yellow No. 9 is a synthetic colorant used in hair dyes, generally considered safe for most people but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyhaircarecolorant
Read ingredient review

Film Former

HDI Alkyl Tartrate Copolymer

HDI/DI-C12-14 ALKYL TARTRATE/HYDROGENATED DILINOLEYL ALCOHOL COPOLYMER

3.8

A synthetic film-former that helps makeup last longer and resist water, but may feel heavy on some skin types.

Irritation

low

Source

synthetic

beautyskincarefilm-former
Read ingredient review

Film Former

HDI/PPG/Polycaprolactone Crosspolymer

HDI/PPG/Polycaprolactone Crosspolymer

4.0

A gentle synthetic film-former that helps makeup and skincare products feel smooth, last longer, and resist water without clogging pores.

Irritation

low

Source

synthetic

beautyskincarefilm-former
Read ingredient review

Film Former

Hea Succinate

Hea Succinate

3.8

Hea Succinate is a synthetic film-former that helps products spread smoothly and feel lightweight on skin, with a low risk of irritation.

Irritation

low

Source

synthetic

beautyskincarefilm-former
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Antioxidant

Heather Flower Extract

Calluna Vulgaris Flower Extract

4.0

A gentle, antioxidant-rich botanical extract that may help calm skin and protect against environmental stress.

Irritation

low

Source

natural

beautyskincareantioxidant
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Soothing Agent

Heather Flower Water

Calluna Vulgaris Flower Water

3.8

A mild, aromatic floral water that may offer soothing and antioxidant benefits, but lacks strong clinical evidence for specific skincare claims.

Irritation

low

Source

natural

beautyskincaresoothing
Read ingredient review

Absorbent

Hectorite

Hectorite

4.0

Hectorite is a gentle clay that helps control shine and thicken formulas without stripping the skin.

Irritation

low

Source

natural

beautyskincaretexturizer
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Antioxidant

Hedera Rhombea Extract

Hedera Rhombea Extract

3.8

A gentle plant extract with antioxidant potential, but research is limited compared to more established botanical ingredients.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Soothing agent

Hedge Bindweed Extract

Calystegia sepium extract

3.5

A gentle botanical extract with antioxidant potential, but research is limited and it's not a skincare powerhouse.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Chelating Agent

HEDTA

HEDTA

3.5

HEDTA is a safe, effective chelating agent that helps your products stay stable and fresh without causing irritation.

Irritation

low

Source

synthetic

beautyskincarechelating agent
Read ingredient review

Antioxidant

Hedychium Coronarium Extract

HEDYCHIUM CORONARIUM FLOWER/LEAF/STEM EXTRACT

3.8

A gentle botanical extract with antioxidant potential, but research on its skincare benefits is still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Hedychium Coronarium Flower Extract

HEDYCHIUM CORONARIUM FLOWER EXTRACT

3.8

A gentle, antioxidant-rich botanical extract that may help calm skin and provide light fragrance, but research on its specific benefits is still limited.

Irritation

low

Source

natural

beautyskincarebotanical
Read ingredient review

Soothing Agent

Hedychium Coronarium Root Extract

HEDYCHIUM CORONARIUM ROOT EXTRACT

3.8

A gentle botanical extract that may help calm skin and provide antioxidant support, though research is still emerging.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Absorbent

Heilmoor Clay

Heilmoor Clay

4.0

Heilmoor Clay is a gentle, mineral-rich clay that helps absorb excess oil and impurities without over-drying, making it a good option for normal to oily skin types.

Irritation

low

Source

natural

beautyskincareabsorbent
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Antioxidant

Heldreich Pine Bark Extract

Pinus Heldreichii Bark Extract

4.0

A gentle, antioxidant-rich botanical extract that helps protect skin from environmental stress, though research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Helichrysum Callus Extract

Helichrysum Italicum Callus Extract

4.0

A gentle, lab-grown antioxidant extract that helps calm skin and fight environmental stress without irritation.

Irritation

low

Source

biotech

beautyskincareantioxidant
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Soothing Agent

Helichrysum Floral Water

Helichrysum Italicum Flower/Leaf/Stem Water

4.0

A gentle, aromatic hydrosol that may help calm skin and provide antioxidant support, but research is limited.

Irritation

low

Source

natural

beautyskincaresoothing
Read ingredient review

Antioxidant

Helichrysum Flower Extract

HELICHRYSUM STOECHAS FLOWER EXTRACT

4.0

A gentle, antioxidant-rich botanical extract that helps calm skin and protect against environmental stress, but research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Helichrysum Flower Oil

HELICHRYSUM STOECHAS FLOWER OIL

4.0

Helichrysum flower oil is a gentle, antioxidant-rich oil that may help calm skin and fight free radical damage, but it's best used in low concentrations due to its potency.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Soothing Agent

Helichrysum Flower Water

Helichrysum Italicum Flower Water

4.0

A mild, aromatic hydrosol that can help calm and soothe the skin while providing a pleasant natural scent.

Irritation

low

Source

natural

beautyskincaresoothing
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Antioxidant

Helichrysum Leaf Cell Extract

Helichrysum Italicum Leaf Cell Extract

4.0

A gentle, lab-grown plant cell extract that may help protect skin from environmental stress and calm irritation, though research is still emerging.

Irritation

low

Source

biotech

beautyskincareantioxidant
Read ingredient review

Antioxidant

Helichrysum Leaf/Stem Extract

Helichrysum Odoratissimum Leaf/Stem Extract

4.0

A gentle, antioxidant-rich botanical extract that helps calm skin and defend against environmental stress.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Helichrysum Root Extract

Helichrysum Italicum Root Extract

4.0

A gentle, antioxidant-rich botanical extract that may help calm skin and protect against environmental stress, though human studies are limited.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Helichrysum Stoechas Extract

Helichrysum Stoechas Extract

4.0

A gentle botanical extract with antioxidant and soothing benefits, best for calming sensitive or stressed skin.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Emollient

Helichrysum Wax

Helichrysum Angustifolium Wax

4.0

A gentle, plant-based wax that helps lock in moisture and gives a smooth, non-greasy feel to skincare products.

Irritation

low

Source

natural

beautyskincareemollient
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Antioxidant

Heliconia Rostrata Leaf Extract

HELICONIA ROSTRATA LEAF EXTRACT

3.8

A gentle, plant-derived antioxidant that may help protect skin from environmental stress, though research is still early.

Irritation

low

Source

natural

beautyskincareantioxidant
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Fragrance Ingredient

Heliotropine

HELIOTROPINE

3.8

Heliotropine is a synthetic fragrance ingredient that adds a sweet, floral, cherry-like scent to products, but offers no direct skincare benefit.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Film former

HEMA

HEMA

3.0

HEMA is a common nail ingredient that can cause allergic reactions in some people, so patch testing is recommended.

Irritation

moderate

Source

synthetic

beautynail careadhesive
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Film Former

HEMA Acetoacetate

HEMA Acetoacetate

3.0

HEMA Acetoacetate is a synthetic ingredient used in nail products for strong adhesion, but it can be a skin sensitizer for some people.

Irritation

moderate

Source

synthetic

beautynail carefilm former
Read ingredient review

Film Former

Hema Glucoside Copolymer

HEMA GLUCOSIDE/ETHYLMETHACRYLATE TRIMONIUM CHLORIDE COPOLYMER

4.0

A gentle conditioning polymer that helps hair feel soft and reduces frizz without heavy buildup.

Irritation

low

Source

synthetic

beautyskincarehaircarefilm former
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Film Former

HEMA Maleate

HEMA Maleate

3.5

HEMA Maleate helps products stick and last longer, but it can be a skin sensitizer for some people, especially in nail formulas.

Irritation

moderate

Source

synthetic

beautyskincarenail carefilm former
Read ingredient review