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

Thickener

Rhizobian Gum

Rhizobian Gum

4.0

Rhizobian Gum is a gentle, natural thickener that improves product texture without clogging pores or causing irritation.

Irritation

low

Source

natural

beautyskincarethickener
Read ingredient review

Skin conditioning agent

Rhizobium Ferment Filtrate

Sinorhizobium Meliloti Ferment Filtrate

4.0

A gentle, biotech-derived ferment that may help strengthen the skin barrier and support a healthy microbiome without irritation.

Irritation

low

Source

biotech

beautyskincaremicrobiome
Read ingredient review

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

beautyskincareantioxidant
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Humectant

Rhizopus/Saccharomyces Collagen Ferment Filtrate

RHIZOPUS/SACCHAROMYCES/COLLAGEN FERMENT FILTRATE

3.8

A fermented collagen ingredient that may help hydrate and condition skin, but research is still early and benefits are not yet proven in large human studies.

Irritation

low

Source

biotech

beautyskincarehumectantconditioning agent
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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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Fragrance

Rhodinol

RHODINOL

3.8

Rhodinol is a natural fragrant alcohol that gives a rose-like scent, but it can be a skin sensitizer for some people.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance Ingredient

Rhodinyl Acetate

RHODINYL ACETATE

3.8

Rhodinyl acetate adds a pleasant rose-like scent to products, but may cause skin irritation in sensitive individuals at higher concentrations.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Rhodinyl Butyrate

RHODINYL BUTYRATE

3.5

A synthetic fragrance ester that adds a floral, rosy note to products; generally safe at low concentrations but may cause sensitivity in those with fragrance allergies.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Rhodinyl Formate

RHODINYL FORMATE

3.5

A synthetic rose-like fragrance ingredient that adds scent but offers no skincare benefit and may irritate sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Rhodinyl Isobutyrate

RHODINYL ISOBUTYRATE

3.5

Rhodinyl isobutyrate is a synthetic fragrance ingredient that adds a floral, rose-like scent to products; it is generally safe at low concentrations but may cause irritation in sensitive individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Rhodinyl Isovalerate

Rhodinyl Isovalerate

3.5

A synthetic rose-like fragrance ingredient that adds a pleasant scent but offers no skincare benefits and may trigger sensitivities in some people.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Rhodinyl Phenylacetate

RHODINYL PHENYLACETATE

3.5

A synthetic floral scent ingredient that is generally safe at low levels but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance

Rhodinyl Propionate

RHODINYL PROPIONATE

3.5

A synthetic floral scent ingredient that is generally safe at low levels but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
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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

beautyskincareantioxidant
Read ingredient review

Colorant

Rhodochrosite Extract

Rhodochrosite Extract

2.5

Rhodochrosite is a natural mineral colorant with no proven skincare benefits beyond its pink hue.

Irritation

low

Source

natural

beautyskincarecolorant
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Skin brightening agent

Rhododendrol

RHODODENDROL

3.5

Rhododendrol is a plant-derived brightener that can help even skin tone, but it carries a moderate risk of irritation and has been linked to a rare skin-lightening disorder in some users.

Irritation

moderate

Source

natural

beautyskincarebrightening agent
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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

beautyskincareantioxidant
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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

beautyskincareantioxidant
Read ingredient review

Soothing Agent

Rhododendron Anthopogon Flower Powder

Rhododendron Anthopogon Flower Powder

3.8

A gentle botanical powder that may offer soothing and antioxidant benefits, but research is limited and it primarily serves as a natural fragrance or texture enhancer.

Irritation

low

Source

natural

beautyskincarebotanical
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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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

Humectant

Rhubarb Fruit Water

Rheum Rhaponticum Fruit Water

3.8

A gentle, hydrating fruit water with mild antioxidant benefits, best for normal to dry skin types.

Irritation

low

Source

natural

beautyskincarehumectant
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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

beautyskincareantioxidant
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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

beautyskincareantioxidant
Read ingredient review

Soothing Agent

Rhubarb Stalk Juice

Rheum Rhabarbarum Stalk Juice

3.8

Rhubarb Stalk Juice is a gentle, plant-based ingredient that may help calm skin and provide antioxidant protection, but research is still emerging.

Irritation

low

Source

natural

beautyskincaresoothing
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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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
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Film Former

Rhus Sap Extract Crosspolymer

ACRYLATES/RHUS VERNICIFLUA SAP EXTRACT CROSSPOLYMER

3.8

A semi-synthetic film former that helps products stay put, but may feel tight or stiff on some skin types.

Irritation

low

Source

semi-synthetic

beautyskincarefilm-former
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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

beautyskincareantioxidant
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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

beautyskincareantioxidant
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Emollient

Rhus Succedanea Fruit Wax

RHUS SUCCEDANEA FRUIT WAX

4.0

A natural fruit wax that provides a smooth, glossy feel and helps thicken products, but may be moderately comedogenic for acne-prone skin.

Irritation

low

Source

natural

beautyskincareemollient
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Exfoliant

Rhyolite Powder

Rhyolite

3.8

Rhyolite powder is a natural volcanic mineral that gently exfoliates and absorbs excess oil, but its benefits are based more on tradition than strong clinical research.

Irritation

low

Source

natural

beautyskincareexfoliant
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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

beautyskincareantioxidant
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Exfoliant

Riberry Fruit Powder

Syzygium luehmannii fruit powder

4.0

A gentle, antioxidant-rich fruit powder that provides mild physical exfoliation and may help brighten skin over time.

Irritation

low

Source

natural

beautyskincareexfoliant
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Emollient

Riberry Seed Oil

Syzygium luehmannii seed oil

4.0

Riberry seed oil is a gentle, antioxidant-rich emollient that helps soften and condition skin without clogging pores.

Irritation

low

Source

natural

beautyskincaremoisturizer
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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

beautyskincareantioxidant
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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

beautyskincareantioxidant
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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

beautyskincareantioxidant
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Exfoliant

Ribonic Acid

RIBONIC ACID

3.8

Ribonic acid is a gentle, less-studied sugar acid that may offer mild exfoliation and antioxidant benefits, but more research is needed to confirm its efficacy compared to better-known AHAs.

Irritation

low

Source

natural

beautyskincareexfoliant
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Exfoliant

Ribonolactone

Ribonolactone

4.0

A gentle PHA exfoliant that smooths skin and boosts hydration with minimal irritation, ideal for sensitive skin.

Irritation

low

Source

semi-synthetic

beautyskincareexfoliant
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Humectant

Ribose

RIBOSE

3.5

Ribose is a gentle sugar molecule that may help energize skin cells and improve hydration, but human research is still limited.

Irritation

low

Source

natural

beautyskincarehumectant
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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

beautyskincareantioxidant
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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

beautyskincareantioxidant
Read ingredient review