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

Soothing Agent

Juniper Berry Water

Juniperus Communis Fruit Water

3.8

A gentle, antioxidant-rich botanical water that adds a subtle herbal note and soothing feel to skincare products.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Juniper Callus Extract

Juniperus Communis Callus Extract

4.0

A gentle, antioxidant-rich plant extract that may help calm skin and fight environmental stress, but research is still early.

Irritation

low

Source

natural

beautyskincareantioxidant
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Soothing Agent

Juniper Seed Water

Juniperus Communis Seed Water

3.8

A mild, water-based botanical extract that may help calm skin and provide antioxidant protection, but research is limited.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Antioxidant

Juniper Sprout Extract

Juniperus Communis Sprout Extract

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Juniper Wood Extract

Juniperus Oxycedrus Wood Extract

3.8

A natural extract with antioxidant and soothing potential, but may cause irritation in sensitive skin due to its aromatic compounds.

Irritation

moderate

Source

natural

beautyskincareantioxidant
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Fragrance

Juniper Wood Oil

Juniperus Communis Wood Oil

4.0

Juniper Wood Oil adds a woody, fresh scent to skincare while offering antioxidant benefits, but it can be irritating for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Soothing agent

Juniper Wood Tar

JUNIPERUS OXYCEDRUS WOOD TAR

3.8

A traditional botanical ingredient with antimicrobial and soothing properties, best for oily or blemish-prone skin, but can be irritating for sensitive types.

Irritation

moderate

Source

natural

beautyskincaresoothing
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Skin conditioning

Juniper Wood Water

Juniperus Communis Wood Water

3.8

A gentle, aromatic water from juniper wood that adds a fresh scent and mild purifying feel to skincare products.

Irritation

low

Source

natural

beautyskincarebotanical
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Antioxidant

Jute Leaf Extract

Corchorus Capsularis Extract

3.8

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

Irritation

low

Source

natural

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Soothing Agent

Jute Leaf Powder

Corchorus Capsularis Powder

3.8

A gentle, plant-based powder that may help calm skin and provide antioxidant protection, but research on its cosmetic benefits is still limited.

Irritation

low

Source

natural

beautyskincarebotanical
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Antioxidant

Jute Leaf/Stem Extract

Corchorus olitorius leaf/stem extract

3.8

A gentle plant extract with antioxidant potential, but research is still early and benefits are not yet proven in human skin.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kadsura Coccinea Fruit Extract

KADSURA COCCINEA FRUIT EXTRACT

3.8

A gentle, antioxidant-rich fruit extract that may help protect skin from environmental stress, though research is still early.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kadsura Coccinea Root Extract

Kadsura Coccinea Root Extract

3.8

A gentle plant extract with antioxidant potential, but research is still early and benefits are not yet proven in humans.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kadsura Japonica Extract

Kadsura Japonica Branch/Fruit/Leaf Extract

3.8

A gentle plant extract with antioxidant potential, but research is still early and benefits are not yet proven in human skin.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kaempferol

KAEMPFEROL

4.0

Kaempferol is a plant-derived antioxidant that helps protect skin from environmental stress and may calm irritation, but human studies are limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kaempferol Rhamnoside

Kaempferol Rhamnoside

3.8

A gentle plant antioxidant that may help calm skin and defend against daily pollution, though human studies are still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kakadu Plum Fruit Extract

Terminalia ferdinandiana fruit extract

4.5

A powerful natural antioxidant from the Kakadu plum, rich in vitamin C, that helps brighten skin and protect against environmental damage.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kalahari Melon Leaf Extract

CYCLOPIA GENISTOIDES LEAF EXTRACT

4.0

A gentle, antioxidant-rich plant extract that may help calm skin and protect against environmental stress, though research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
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Soothing agent

Kalanchoe Leaf Extract

KALANCHOE GASTONIS-BONNIERI LEAF EXTRACT

3.8

A gentle plant extract with potential soothing and antioxidant benefits, but research on this specific species is limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Soothing Agent

Kalanchoe Spathulata Extract

Kalanchoe Spathulata Extract

3.8

A gentle, plant-derived extract with antioxidant and soothing potential, though clinical evidence in humans is still limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Antioxidant

Kale Leaf Extract

Brassica Oleracea Acephala Leaf Extract

4.0

Kale Leaf Extract is a gentle antioxidant-rich ingredient that helps protect skin from environmental stress while providing soothing benefits.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kale Powder

Brassica Oleracea Acephala Powder

4.0

Kale powder brings antioxidant and nutrient benefits to skincare, but its effects are mild and best used as part of a broader antioxidant strategy.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kale Sprout Extract

Brassica Oleracea Acephala Sprout Extract

4.0

Kale sprout extract is a gentle antioxidant-rich ingredient that helps protect skin from environmental stress and may calm irritation.

Irritation

low

Source

natural

beautyskincareantioxidant
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Exfoliant

Kallikrein

Kallikrein

3.5

Kallikrein is a skin enzyme that gently exfoliates by breaking down dead skin cells, but its use in cosmetics is still emerging and may cause irritation for sensitive skin.

Irritation

moderate

Source

biotech

beautyskincareexfoliant
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Antioxidant

Kamala Bark Extract

MALLOTUS PHILIPPENSIS BARK EXTRACT

3.8

Kamala bark extract is a gentle antioxidant from a tropical tree, but research on its skincare benefits is still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kamala Fruit Extract

Mallotus Philippensis Fruit Extract

3.8

A gentle plant extract with antioxidant potential, but research is limited and it's not a proven powerhouse ingredient.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kamchatka Rose Fruit Extract

Rosa Kamchatica Fruit Extract

4.0

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

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kangaroo Apple Fruit Extract

Solanum Aviculare Fruit Extract

3.5

A gentle plant extract with antioxidant potential, but research on its specific skin benefits is still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kangaroo Apple Leaf Extract

Solanum Aviculare Leaf Extract

3.5

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

Irritation

low

Source

natural

beautyskincarebotanical extract
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Emollient

Kangaroo Apple Seed Oil

Solanum Aviculare Seed Oil

3.8

A gentle, plant-based emollient oil that softens skin with a light feel, though research on its unique benefits is still limited.

Irritation

low

Source

natural

beautyskincareemollient
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Antioxidant

Kangaroo Paw Extract

ANIGOZANTHOS FLAVIDUS EXTRACT

3.8

A gentle, antioxidant-rich plant extract that may help calm skin and protect against environmental stress, though research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kangaroo Paw Flower Extract

ANIGOZANTHOS FLAVIDUS FLOWER EXTRACT

3.8

A gentle, antioxidant-rich flower extract that may help calm skin and protect against environmental stress, though research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kangaroo Paw Flower/Leaf Extract

ANIGOZANTHOS FLAVIDUS FLOWER/LEAF EXTRACT

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
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Soothing agent

Kanokosou Extract

Kanokosou Ekisu

3.5

Kanokosou extract is a gentle botanical with potential soothing benefits, but research is limited and it's not a proven powerhouse.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Soothing Agent

Kantakari Fruit Powder

Solanum Xanthocarpum Powder

3.8

A gentle botanical powder with antioxidant and soothing potential, best known from traditional Ayurvedic use but with limited modern cosmetic research.

Irritation

low

Source

natural

beautyskincarebotanical
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Soothing Agent

Kanzou Ekisu

Glycyrrhiza Glabra (Licorice) Root Extract

4.5

Licorice root extract is a gentle, research-backed ingredient that helps calm redness and even out skin tone without harsh side effects.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Absorbent

Kaolin

Kaolin

4.2

Kaolin is a mild clay that soaks up surface oil and dirt, making it a go-to for oily or combination skin without over-drying.

Irritation

low

Source

natural

beautyskincareabsorbent
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Absorbent

Kaolin Clay

Kaolin

4.2

Kaolin is a mild, oil-absorbing clay that helps clarify skin without over-drying, making it a go-to for normal to oily skin types.

Irritation

low

Source

natural

beautyskincareabsorbent
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Antioxidant

Karamu Leaf/Stem Extract

COPROSMA GRANDIFOLIA LEAF/STEM EXTRACT

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
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Soothing Agent

Kava Kava Root Extract

Piper Methysticum Rhizome/Root Extract

3.8

Kava Kava Root Extract is a gentle botanical that may help calm irritated skin and provide antioxidant protection, but its use in skincare is less common and requires careful sourcing.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Humectant

Kefiran

Kefiran

4.0

Kefiran is a gentle, hydrating polysaccharide from kefir that helps skin retain moisture and may support a healthy-looking barrier.

Irritation

low

Source

natural

beautyskincarehumectant
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Antioxidant

Keihi Ekisu (Fermented Plant Extract)

Lactobacillus/Wasabia Japonica Root Ferment Extract, Lactobacillus/Punica Granatum Fruit Ferment Extract, Lactobacillus/Saccharum Officinarum (Sugarcane) Ferment Extract, Lactobacillus/Saccharomyces/Xylinum/Black Tea Ferment

3.8

A fermented botanical blend that may offer antioxidant and soothing benefits, but research is limited.

Irritation

low

Source

biotech

beautyskincareantioxidant
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Antioxidant

Keihi Yu

KEIHI YU

3.5

Keihi Yu is a gentle herbal extract with antioxidant potential, but research on its cosmetic benefits is limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Humectant

Kelp Extract

Nereocystis leutkeana extract

4.0

A mineral-rich seaweed extract that hydrates and soothes skin, but its benefits come mostly from its nutrient profile rather than unique active compounds.

Irritation

low

Source

natural

beautyskincarehumectant
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Humectant

Kelp Juice

Macrocystis Pyrifera Juice

4.0

A mineral-rich seaweed juice that hydrates and soothes skin without clogging pores.

Irritation

low

Source

natural

beautyskincarehumectant
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Humectant

Kelp Juice Extract

Macrocystis Pyrifera Blade/Pneumatocyst/Stipe Juice Extract

4.0

A gentle, hydrating seaweed extract that helps soothe and moisturize skin without clogging pores.

Irritation

low

Source

natural

beautyskincarehumectant
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Antioxidant

Kenilworth Ivy Extract

LINARIA CYMBALARIA FLOWER/LEAF/STEM EXTRACT

3.5

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

Irritation

low

Source

natural

beautyskincarebotanical extract
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Anti-aging agent

Kephalis

Kephalis

4.0

Kephalis is a synthetic peptide that may help smooth wrinkles and support skin firmness, but research is still emerging.

Irritation

low

Source

synthetic

beautyskincareanti-aging
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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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Exfoliant

Keratinase

Keratinase

4.0

Keratinase is a gentle enzyme exfoliant that targets dead skin cells and rough skin without harsh scrubbing.

Irritation

low

Source

biotech

beautyskincareexfoliant
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Antioxidant

Kerria Japonica Flower Extract

Kerria Japonica Flower Extract

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
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Exfoliant

Ketoglutaric Acid

KETOGLUTARIC ACID

3.8

A gentle alpha-keto acid that exfoliates and supports skin renewal with low irritation potential.

Irritation

low

Source

natural

beautyskincareexfoliant
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Eyelash Growth Enhancer

Ketotravoprost

KETOTRAVOPROST

2.5

Ketotravoprost is a potent synthetic ingredient that can stimulate eyelash growth but carries risks of eye irritation, darkening of the eyelid skin, and potential changes in eye color.

Irritation

high

Source

synthetic

beautyskincareeyelash
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Soothing agent

Kidachi Aloe Extract

Aloe Arborescens Leaf Extract

4.0

Kidachi Aloe Extract is a gentle, hydrating botanical that helps calm irritated skin and provides antioxidant protection, making it a great alternative to Aloe vera for sensitive skin.

Irritation

low

Source

natural

beautyskincaresoothing agent
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