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 4,092
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

Renealmia Leaf Extract

Renealmia Guianensis Leaf Extract

3.5

A gentle, plant-derived extract with emerging research suggesting antioxidant and soothing benefits, but more studies are needed to confirm its efficacy in skincare.

Irritation

low

Source

natural

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Antioxidant

Repagermanium

Repagermanium

2.5

Repagermanium is a synthetic germanium compound with limited evidence for skin benefits; its use in cosmetics is rare and not well-supported by robust research.

Irritation

low

Source

synthetic

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Antioxidant

Resacetophenone

Resacetophenone

3.8

Resacetophenone is a synthetic antioxidant that helps stabilize formulas and protect skin from environmental stress.

Irritation

low

Source

synthetic

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Antioxidant

Resorcinol Dihexyl Ether

RESORCINOL DIHEXYL ETHER

3.8

A synthetic antioxidant that may help brighten skin and even out tone, but research is still limited compared to more established ingredients.

Irritation

low

Source

synthetic

beautyskincareantioxidant
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Antioxidant

Resveratrol

Resveratrol

4.2

Resveratrol is a potent antioxidant that helps defend skin from oxidative stress, but its benefits are best supported when combined with other antioxidants and used consistently over time.

Irritation

low

Source

natural

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Antioxidant

Resveratrol Dimethyl Ether Oligosaccharides

Resveratrol Dimethyl Ether Oligosaccharides

4.0

A stabilized, sugar-bound form of resveratrol that offers antioxidant protection with potentially better skin penetration and less irritation than plain resveratrol.

Irritation

low

Source

semi-synthetic

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Antioxidant

Resveratrol Tributyl Ether

Resveratrol Tributyl Ether

4.0

A stabilized version of resveratrol that may help protect skin from environmental stress, though human studies are still limited.

Irritation

low

Source

semi-synthetic

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Antioxidant

Resveratrol Tripentyl Ether

RESVERATROL TRIPENTYL ETHER

4.0

A more stable, oil-friendly version of resveratrol that helps protect skin from environmental stress without the formulation challenges of plain resveratrol.

Irritation

low

Source

semi-synthetic

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Antioxidant

Resveratryl Acetate

Resveratryl Acetate

4.0

A gentle, stabilized version of resveratrol that offers antioxidant protection and helps calm the skin without the stability issues of natural resveratrol.

Irritation

low

Source

semi-synthetic

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Antioxidant

Resveratryl Ferulate

Resveratryl Ferulate

4.3

A potent antioxidant that pairs two well-known plant compounds for better stability and skin protection.

Irritation

low

Source

semi-synthetic

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Antioxidant

Resveratryl Glucoside

Resveratryl Glucoside

4.3

A gentle, water-friendly antioxidant that helps protect skin from environmental stress without the stability issues of plain resveratrol.

Irritation

low

Source

semi-synthetic

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Antioxidant

Resveratryl Triacetate

Resveratryl Triacetate

4.0

A more stable, oil-friendly version of resveratrol that helps defend skin from environmental stress and supports a more even-looking complexion.

Irritation

low

Source

semi-synthetic

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Antioxidant

Resveratryl Tricaprylate

Resveratryl Tricaprylate

4.0

A stabilized, oil-soluble form of resveratrol that offers antioxidant protection and anti-aging benefits with better stability and skin penetration than plain resveratrol.

Irritation

low

Source

semi-synthetic

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Antioxidant

Resveratryl Tris-Ethylhexanoate

Resveratryl Tris-Ethylhexanoate

4.0

A stabilized, oil-soluble version of resveratrol that offers antioxidant benefits with better skin penetration and less irritation than plain resveratrol.

Irritation

low

Source

semi-synthetic

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Antioxidant

Retinyl Linoleate

RETINYL LINOLEATE

4.0

A milder retinoid that converts to retinol on skin, offering anti-aging benefits with less irritation than pure retinol.

Irritation

low

Source

semi-synthetic

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Antioxidant

Retinyl Oleate

Retinyl Oleate

3.8

A gentler vitamin A derivative that may offer anti-aging benefits with less irritation than pure retinol, but with less research backing.

Irritation

moderate

Source

semi-synthetic

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Antioxidant

Reynoutria Fruit Extract

Reynoutria Sachalinensis Fruit Extract

4.0

A gentle plant extract that helps protect skin from environmental stress and may calm irritation, though research is still emerging.

Irritation

low

Source

natural

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Antioxidant

Rhein

Rhein

3.8

Rhein is a plant-derived antioxidant with emerging research for soothing and protecting skin, but more human studies are needed to confirm its benefits.

Irritation

low

Source

natural

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Antioxidant

Rhizome Extract

RHYOLITE EXTRACT

3.5

A gentle botanical extract with antioxidant potential, but research is limited and its benefits are not well-established.

Irritation

low

Source

natural

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Humectant

Rhodella Violacea Extract

Rhodella Violacea Extract

4.0

A gentle, hydrating microalgae extract that helps skin retain moisture and defends against environmental stress.

Irritation

low

Source

natural

beautyskincarehumectantantioxidant
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Antioxidant

Rhodiola Ferment Extract

SACCHAROMYCES/RHODIOLA CRENULATA ROOT EXTRACT FERMENT FILTRATE

4.0

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

Irritation

low

Source

biotech

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Antioxidant

Rhodiola Rosea Callus Extract

Rhodiola Rosea Callus Extract

4.0

Rhodiola rosea callus extract is a gentle antioxidant that may help protect skin from environmental stress and support a more resilient complexion.

Irritation

low

Source

natural

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Antioxidant

Rhodiola Rosea Root Extract

Sedum Rosea Root Extract

4.0

Rhodiola rosea root extract is a gentle antioxidant-rich ingredient that may help protect skin from environmental stress and support a calm, even-looking complexion.

Irritation

low

Source

natural

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Antioxidant

Rhododendron Adamsii Extract

Rhododendron Adamsii Leaf/Stem Extract

3.8

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

Irritation

low

Source

natural

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Antioxidant

Rhododendron Anthopogon Extract

RHODODENDRON ANTHOPOGON FLOWER/LEAF EXTRACT

3.8

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

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Antioxidant

Rhododendron Bark Extract

Rhododendron Arboreum Bark Extract

3.8

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

Irritation

low

Source

natural

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Antioxidant

Rhododendron Extract

Rhododendron Yedoense Branch/Leaf Extract

3.8

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

Irritation

low

Source

natural

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Antioxidant

Rhododendron Flower Extract

Rhododendron Weyrichii Flower Extract

3.8

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

Irritation

low

Source

natural

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Antioxidant

Rhododendron Flower Ferment Extract

Bacillus/Rhododendron Weyrichii Flower Ferment Extract Filtrate

4.0

A gentle, fermented flower extract that may help calm skin and defend against environmental stress, though research is still early.

Irritation

low

Source

biotech

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Antioxidant

Rhododendron Leaf Cell Culture Extract

Rhododendron Ferrugineum Leaf Cell Culture Extract

4.0

A gentle, lab-grown antioxidant from alpine rose that may help protect skin from environmental stress, though human studies are limited.

Irritation

low

Source

biotech

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Antioxidant

Rhododendron Weyrichii Extract

Rhododendron Weyrichii Extract

3.8

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

Irritation

low

Source

natural

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Antioxidant

Rhodopseudomonas Ferment Extract

RHODOPSEUDOMONAS FERMENT EXTRACT

4.0

A gentle, probiotic-derived antioxidant that may help calm skin and support a healthy skin barrier, though research is still emerging.

Irritation

low

Source

biotech

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Antioxidant

Rhodopseudomonas PABA Ferment

RHODOPSEUDOMONAS/PABA FERMENT

3.8

A gentle, biotech-derived ferment that may help calm skin and fight oxidative stress, but human research is still limited.

Irritation

low

Source

biotech

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Antioxidant

Rhubarb Root Extract

Rheum Undulatum Root/Stalk/Stem Extract

3.8

A gentle plant extract that may help calm skin and fight free radicals, but research is still early.

Irritation

low

Source

natural

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Antioxidant

Rhubarb Stalk Extract

Rheum Rhabarbarum Stalk 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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Antioxidant

Rhubarb Stem Extract

Rheum Officinale Stem Extract

3.8

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

Irritation

low

Source

natural

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Antioxidant

Rhus Cotinus Leaf Extract

Rhus Cotinus Leaf Extract

4.0

A gentle plant extract with antioxidant and soothing potential, though research on its cosmetic benefits is still emerging.

Irritation

low

Source

natural

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Antioxidant

Rhus Javanica Fruit Extract

Rhus Javanica Fruit Extract

3.8

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

Irritation

low

Source

natural

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Antioxidant

Rhus Semialata Gall Extract

Rhus Semialata Gall Extract

4.0

A gentle, plant-based antioxidant extract that helps protect skin from environmental stress and may calm irritation.

Irritation

low

Source

natural

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Antioxidant

Rhus Semialata Leaf Extract

Rhus Semialata Leaf Extract

4.0

A gentle botanical extract with antioxidant and soothing potential, though research is still early-stage.

Irritation

low

Source

natural

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Antioxidant

Riberry Fruit Extract

Syzygium luehmannii fruit extract

4.0

Riberry fruit extract is a gentle, antioxidant-rich ingredient that helps protect skin from environmental stress while providing mild hydration and soothing benefits.

Irritation

low

Source

natural

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Antioxidant

Riboflavin

Riboflavin

3.8

Riboflavin is a gentle antioxidant that may help brighten skin and protect against environmental stress, but it is less studied than other vitamins like C or E.

Irritation

low

Source

natural

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Antioxidant

Riboflavin Tetraacetate

Riboflavin Tetraacetate

3.8

A gentle, stabilized form of vitamin B2 that may help protect skin from oxidative stress and support a more even tone, though research is still early.

Irritation

low

Source

semi-synthetic

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Antioxidant

Riboflavin Tetrabutyrate

RIBOFLAVIN TETRABUTYRATE

3.8

A fat-soluble form of vitamin B2 that may help protect skin from oxidative stress and support a more even tone, though human studies are limited.

Irritation

low

Source

semi-synthetic

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Antioxidant

Rice Bean Seed Extract

Vigna Umbellata Seed Extract

3.8

A gentle plant extract that may help protect skin from environmental stress, but research is still early.

Irritation

low

Source

natural

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Antioxidant

Rice Bran & Germ Extract

Oryza Sativa (Rice) Bran/Germ Extract

4.2

A gentle, antioxidant-rich extract from rice that helps nourish and protect the skin without irritation.

Irritation

low

Source

natural

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Antioxidant

Rice Callus Culture Extract

Oryza Sativa (Rice) 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

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Humectant

Rice Ferment Lees

Rice Ferment Lees

4.0

A gentle, nutrient-rich byproduct of sake brewing that hydrates, soothes, and supports a brighter, more even skin tone.

Irritation

low

Source

natural

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Antioxidant

Rice Germ Cell Culture Extract

Oryza Sativa (Rice) Germ Cell Culture Extract

4.0

A gentle, plant-based ingredient that may help protect skin from environmental stress and support a healthy moisture barrier.

Irritation

low

Source

biotech

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Antioxidant

Rice Germ Extract

ORYZA SATIVA GERM EXTRACT

4.0

Rice germ extract is a gentle, antioxidant-rich ingredient that helps protect and nourish the skin without irritation.

Irritation

low

Source

natural

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Antioxidant

Rice Leaf Extract

Oryza Sativa Leaf Extract

4.0

A gentle, antioxidant-rich extract from rice leaves that helps protect skin from environmental stress and supports a calm, even-looking complexion.

Irritation

low

Source

natural

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Antioxidant

Rice Leaf/Stem Extract

ORYZA SATIVA LEAF/STEM EXTRACT

3.8

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

Irritation

low

Source

natural

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Antioxidant

Rice Lees Extract

ORYZA SATIVA LEES EXTRACT

4.0

A gentle, fermented rice byproduct that may help soothe skin and provide antioxidant benefits, though research is still emerging.

Irritation

low

Source

natural

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Skin Conditioning Agent

Rice Sprout Ferment Filtrate

SACCHAROMYCES/RICE SPROUT FERMENT FILTRATE

4.0

A gentle fermented ingredient that may help soothe and brighten skin while supporting its natural barrier.

Irritation

low

Source

biotech

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