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

Kidachi Aloe Ferment

Aloe Arborescens Leaf Extract, Lactobacillus/Soybean Ferment Extract, Glycerin

4.0

A fermented aloe complex that offers gentle hydration and soothing benefits, though research on the specific blend is limited.

Irritation

low

Source

mixed

beautyskincaresoothing agent
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Antioxidant

Kidney Vetch Extract

ANTHYLLIS VULNERARIA EXTRACT

3.8

A gentle botanical extract with traditional use for soothing skin, though modern research is still limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Soothing agent

Kidney Vetch Flower Extract

ANTHYLLIS VULNERARIA FLOWER EXTRACT

3.8

A gentle botanical extract with traditional use for soothing skin, though modern research is still limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Soothing Agent

Kina Ekisu

Kina Ekisu

3.8

Kina Ekisu is a gentle botanical extract with potential soothing and antioxidant benefits, but research in cosmetics is limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Anti-aging agent

Kinetin

Kinetin

4.0

Kinetin is a gentle plant-derived ingredient that may help improve skin texture and reduce fine lines without the irritation of stronger anti-aging actives.

Irritation

low

Source

natural

beautyskincareanti-aging
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Antioxidant

Kinginka Ekisu

Chrysanthemum Indicum Flower Extract

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
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Skin conditioning agent

Kitasatospora Ferment Filtrate

Kitasatospora Ferment Filtrate

3.8

A gentle, microbiome-friendly ingredient from bacterial fermentation that may help balance skin and reduce sensitivity over time.

Irritation

low

Source

biotech

beautyskincaremicrobiome
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Humectant

Kiwi Fruit Beta-Glucan Extract

Actinidia Chinensis (Kiwi) Fruit Extract, Beta-Glucan

4.0

A gentle, hydrating ingredient that combines fruit extract with beta-glucan to help soothe and moisturize the skin.

Irritation

low

Source

natural

beautyskincarehumectant
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Antioxidant

Kiwi Fruit Extract

Actinidia Deliciosa Fruit Extract

4.0

Kiwi Fruit Extract is a gentle, antioxidant-rich ingredient that helps brighten and soothe skin, but its benefits are best supported by the fruit's general nutritional profile rather than extensive cosmetic-specific studies.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kiwi Seed Extract

Actinidia Chinensis Seed Extract

4.0

A gentle, antioxidant-rich oil from kiwi seeds that helps nourish and protect the skin without clogging pores.

Irritation

low

Source

natural

beautyskincareantioxidant
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Emollient

Kiwi Seed Oil

Actinidia Chinensis Seed Oil

4.2

Kiwi seed oil is a gentle, antioxidant-rich oil that hydrates and softens skin without clogging pores, making it a great choice for most skin types.

Irritation

low

Source

natural

beautyskincareemollient
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Emollient

Kiwi Seed Oil Esters

KIWI SEED OIL/PALM OIL AMINOPROPANEDIOL ESTERS

4.0

A gentle, plant-derived emollient that helps soften skin without clogging pores, but its palm oil component raises sustainability questions.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Emollient

Kniphofia Uvaria Seed Oil

KNIPHOFIA UVARIA SEED OIL

3.8

A gentle, plant-based oil that hydrates and soothes skin, though research on its benefits is still limited.

Irritation

low

Source

natural

beautyskincareemollient
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Humectant

Knotted Kelp Extract

ASCOPHYLLUM NODOSUM EXTRACT

4.0

A nutrient-rich seaweed extract that helps hydrate and calm the skin, with antioxidant benefits from coastal minerals.

Irritation

low

Source

natural

beautyskincarehumectantsoothing
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Fragrance

Kobayashi Mandarin Peel Water

Citrus Sphaerocarpa Peel Water

3.8

A gentle, citrus-derived water that adds light antioxidant benefits and a fresh scent, but its effects are mild and mostly aromatic.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kochia Scoparia Fruit Extract

Kochia Scoparia Fruit Extract

3.8

A gentle, plant-derived extract with antioxidant and soothing potential, though human research is still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Exfoliant

Kochia Scoparia Fruit Powder

KOCHIA SCOPARIA FRUIT POWDER

3.8

A gentle, plant-based powder that can help polish skin without harsh microbeads, but research on its benefits is still limited.

Irritation

low

Source

natural

beautyskincareexfoliant
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Antioxidant

Kohlrabi Extract

Brassica Oleracea Gongylodes Extract

3.8

A gentle, antioxidant-rich plant extract that may help soothe and protect skin, but research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kohlrabi Sprout Extract

Brassica Oleracea Gongylodes Sprout Extract

4.0

A gentle, antioxidant-rich plant extract that may help soothe and protect skin from environmental stress.

Irritation

low

Source

natural

beautyskincareantioxidant
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Tyrosinase inhibitor

Kojic Acid

Kojic Acid

4.2

Kojic acid is a well-known skin brightener that works by blocking melanin production, but it can be irritating for sensitive skin and is less stable than some alternatives.

Irritation

moderate

Source

natural

beautyskincarebrightening agent
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Skin brightening agent

Kojic Dipalmitate

Kojic Dipalmitate

4.0

A gentler, more stable version of kojic acid that targets dark spots without the irritation or instability of the original.

Irritation

low

Source

semi-synthetic

beautyskincarebrightening agent
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Skin brightener

Kojic Isopalmitate

Kojic Isopalmitate

4.0

A gentler, more stable version of kojic acid that helps fade dark spots and even out skin tone without the irritation of the original.

Irritation

low

Source

semi-synthetic

beautyskincarebrightening agent
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Skin brightener

Kojyl Carboxy Dipeptide-23

Kojyl Carboxy Dipeptide-23

3.8

A synthetic peptide that may help brighten skin and fade dark spots, but research is still limited.

Irritation

low

Source

synthetic

beautyskincarebrightening agent
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Skin brightening agent

Kojyl Carboxy SH-Oligopeptide-75 Amide

KOJYL CARBOXY SH-OLIGOPEPTIDE-75 AMIDE

4.0

A synthetic peptide that aims to brighten skin and reduce fine lines by combining a kojic acid-like signal with a collagen-supporting peptide.

Irritation

low

Source

synthetic

beautyskincarepeptide
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Skin brightener

Kojyl Glucoside

Kojyl Glucoside

4.0

A gentle, stabilized alternative to kojic acid that helps fade dark spots with less irritation risk.

Irritation

low

Source

semi-synthetic

beautyskincarebrightening agent
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Skin brightener

Kojyl Methylenedioxycinnamate

KOJYL METHYLENEDIOXYCINNAMATE

3.5

A synthetic brightener with limited research; may help even skin tone but lacks strong safety and efficacy data.

Irritation

moderate

Source

synthetic

beautyskincarebrightening agent
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Skin Lightening Agent

Kojylmethyl Dichlorobenzyl Piperazine

KOJYLMETHYL DICHLOROBENZYL PIPERAZINE

3.5

A synthetic tyrosinase inhibitor that may help fade dark spots, but research is limited and irritation is possible.

Irritation

moderate

Source

synthetic

beautyskincareskin lightening
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Soothing agent

Kokanica Ferula Resin Oil

Ferula Kokanica Resin Oil

3.8

A gentle, antioxidant-rich resin oil from a rare plant, best for soothing sensitive skin, but research is limited.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Soothing Agent

Kokanica Gum Extract

Ferula Kokanica Gum Extract

3.8

A gentle, plant-derived gum that may help calm skin and create a light protective layer, but research is still limited.

Irritation

low

Source

natural

beautyskincaresoothing agent
Read ingredient review

Humectant

Kombucha Ferment Extract

Gluconacetobacter Xylinus Ferment Filtrate Extract

4.0

A gentle, fermented ingredient that hydrates and soothes skin, but its benefits are mostly anecdotal and backed by limited clinical research.

Irritation

low

Source

natural

beautyskincarehumectant
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Humectant

Konjac Root Extract

AMORPHOPHALLUS KONJAC ROOT EXTRACT

4.2

Konjac root extract is a gentle, plant-based humectant that helps hydrate and soothe the skin without clogging pores.

Irritation

low

Source

natural

beautyskincarehumectant
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Exfoliant

Konjac Root Powder

AMORPHOPHALLUS KONJAC ROOT POWDER

4.0

A gentle, natural exfoliant from konjac root that helps smooth skin without harsh scrubbing.

Irritation

low

Source

natural

beautyskincareexfoliant
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Antioxidant

Korean Acanthopanax Fruit Extract

Acanthopanax Koreanum Fruit Extract

4.0

A gentle, antioxidant-rich fruit extract that helps protect skin from environmental stress while offering mild soothing benefits.

Irritation

low

Source

natural

beautyskincareantioxidant
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Emollient

Korean Acanthopanax Oil

Acanthopanax Koreanum Oil

3.8

A gentle, antioxidant-rich oil that helps soothe and moisturize skin, but research on its specific benefits is still limited.

Irritation

low

Source

natural

beautyskincareemollient
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Soothing Agent

Korean Aconite Extract

Aconitum Koreanum Extract

3.5

A traditional plant extract with potential soothing benefits, but limited modern research and a need for cautious formulation due to its alkaloid content.

Irritation

moderate

Source

natural

beautyskincaresoothing
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Antioxidant

Korean Black Raspberry Extract

Rubus crataegifolius fruit extract

4.0

A gentle, antioxidant-rich fruit extract that may help protect skin from environmental stress and support a more even tone.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Korean Black Raspberry Ferment

SACCHAROMYCES/RUBUS COREANUS FRUIT FERMENT FILTRATE

4.0

A fermented fruit extract that delivers antioxidants and gentle skin conditioning, but its benefits depend heavily on the fermentation process and formulation.

Irritation

low

Source

biotech

beautyskincareantioxidant
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Antioxidant

Korean Black Raspberry Fruit Water

Rubus Crataegifolius Fruit Water

4.0

A gentle, antioxidant-rich fruit water that hydrates and soothes skin, but its benefits are largely from the water content and trace nutrients rather than a concentrated active.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Korean Bugleweed Callus Extract

LYCOPUS COREANUS CALLUS CULTURE EXTRACT

3.8

A plant-based antioxidant from lab-grown cells that may help calm skin and fight free radical damage, but research is still early.

Irritation

low

Source

biotech

beautyskincareantioxidant
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Antioxidant

Korean Bugleweed Leaf Extract

Lycopus coreanus 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

Korean Cherry Fruit Extract

Prunus Tomentosa Fruit Extract

3.8

A gentle, antioxidant-rich fruit extract that may help calm skin and fight environmental damage, though research is still early.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Korean Fir Leaf Extract

Abies Koreana Leaf Extract

4.0

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

Irritation

low

Source

natural

beautyskincareantioxidant
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Exfoliant

Korean Fir Leaf Powder

Abies Koreana Leaf Powder

3.8

A gentle, natural exfoliating powder from Korean fir leaves that also offers antioxidant benefits, but may cause irritation if particles are too large or used too frequently.

Irritation

moderate

Source

natural

beautyskincareexfoliant
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Antioxidant

Korean Ginseng Bark Ferment

Kluyveromyces/Lactobacillus/Acanthopanax Koreanum Bark/Stem Oil Ferment Filtrate

4.0

A fermented botanical extract that may help calm irritation and defend against environmental stress, though human studies are limited.

Irritation

low

Source

biotech

beautyskincareantioxidant
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Antioxidant

Korean Herb Root Complex

Angelica Acutiloba Root Extract, Paeonia Lactiflora Root Extract, Rehmannia Glutinosa Root Extract, Cnidium Officinale Rhizome Extract

3.8

A traditional herbal root blend that may offer antioxidant and soothing benefits, but clinical evidence on skin is limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Antioxidant

Korean Monk's Hood Flower Extract

Aconitum Austrokoreense Flower Extract

3.5

A rare botanical extract with potential antioxidant benefits, but limited research and a known toxicity concern in the raw plant family require careful processing and low concentrations.

Irritation

moderate

Source

natural

beautyskincarebotanical extract
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Antioxidant

Korean Pine Callus Extract

Pinus Koraiensis Callus Culture Extract

4.0

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

Irritation

low

Source

biotech

beautyskincareantioxidant
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Antioxidant

Korean Prickly Ash Extract

ZANTHOXYLUM COREANUM BRANCH/LEAF EXTRACT

3.8

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

Irritation

low

Source

natural

beautyskincarebotanical extract
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Antioxidant

Korean Pulsatilla Root Extract

Pulsatilla Koreana Root Extract

3.8

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

Irritation

low

Source

natural

beautyskincarebotanical extract
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Antioxidant

Korean Rowan Branch/Leaf Extract

SORBUS ALNIFOLIA BRANCH/LEAF EXTRACT

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Korean Rowan Leaf Extract

SORBUS ALNIFOLIA LEAF/STEM EXTRACT

3.8

A gentle, plant-derived antioxidant that may help calm skin and defend against environmental stress, though research is still early.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Korean Stewartia Leaf Extract

Stewartia Koreana Leaf 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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Soothing Agent

Korean Willow Stem Extract

Salix Gracilistyla Stem Extract

3.8

A gentle botanical extract from Korean willow that may help calm irritated skin and provide antioxidant protection, though research is still emerging.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Antioxidant

Korthalsella Japonica Extract

Korthalsella Japonica Extract

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Kou-Cha Extract

KOU-CHA EKISU

4.0

A gentle, fermented black tea extract that offers antioxidant protection and soothing benefits, ideal for most skin types.

Irritation

low

Source

natural

beautyskincareantioxidant
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