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

Absorbent

Red Poppy Flower Powder

PAPAVER RHOEAS FLOWER POWDER

3.5

Red Poppy Flower Powder adds gentle texture and a natural tint to powders and soaps, but its skincare benefits beyond physical exfoliation are not well-studied.

Irritation

low

Source

natural

beautyskincarecosmetic
Read ingredient review

Antioxidant

Red Raspberry Bud Extract

Rubus Idaeus Bud Extract

4.0

A gentle, antioxidant-rich extract from raspberry buds that helps protect skin from environmental stress and may calm minor irritation.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Red Raspberry Callus Extract

RUBUS IDAEUS CALLUS EXTRACT

4.0

A gentle, antioxidant-rich extract from red raspberry cells that may help protect skin from environmental stress and soothe irritation.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Red Raspberry Fruit Extract

RUBUS IDAEUS FRUIT EXTRACT

4.0

Red Raspberry Fruit Extract is a gentle antioxidant that helps protect skin from environmental stressors and may soothe irritation.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Red Raspberry Leaf Cell Culture

Rubus Idaeus Leaf Cell Culture

4.0

A gentle, lab-grown antioxidant from raspberry cells that may help protect skin from environmental stress and support a more even tone.

Irritation

low

Source

biotech

beautyskincareantioxidant
Read ingredient review

Antioxidant

Red Raspberry Leaf Powder

RUBUS IDAEUS LEAF POWDER

3.8

A gentle botanical powder that may offer antioxidant and soothing benefits, but research on its topical effects is limited.

Irritation

low

Source

natural

beautyskincarebotanical
Read ingredient review

Emollient

Red Raspberry Leaf Wax

RUBUS IDAEUS LEAF WAX

4.0

A gentle, plant-derived wax that adds richness and a smooth feel to balms and sticks without clogging pores.

Irritation

low

Source

natural

beautyskincareemollient
Read ingredient review

Exfoliant

Red Raspberry Seed

Rubus Strigosus Seed

4.0

Red raspberry seed is a gentle, natural exfoliant that also provides antioxidant benefits, making it a good choice for sensitive skin types.

Irritation

low

Source

natural

beautyskincareexfoliant
Read ingredient review

Antioxidant

Red Raspberry Seed Extract

Rubus Idaeus Seed Extract

4.0

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Emollient

Red Raspberry Seed Oil

RUBUS IDAEUS SEED OIL

4.3

A lightweight, antioxidant-rich oil that hydrates and helps protect skin from environmental stress without clogging pores.

Irritation

low

Source

natural

beautyskincareemollient
Read ingredient review

Exfoliant

Red Raspberry Seedcake Powder

RUBUS IDAEUS SEEDCAKE POWDER

4.0

A gentle, natural exfoliant from raspberry seeds that polishes skin without harsh microbeads, with mild antioxidant properties.

Irritation

low

Source

natural

beautyskincareexfoliant
Read ingredient review

Exfoliant

Red Rice Vinegar

Red Rice Vinegar

3.8

A gentle, naturally fermented exfoliant that may help brighten skin and improve texture, but research is limited compared to standard AHAs.

Irritation

low

Source

natural

beautyskincareexfoliant
Read ingredient review

Soothing Agent

Red Sandalwood Extract

PTEROCARPUS SANTALINUS STEM EXTRACT

4.0

A gentle botanical extract that may help calm redness and provide antioxidant protection, though human studies are limited.

Irritation

low

Source

natural

beautyskincaresoothing
Read ingredient review

Absorbent

Red Sandalwood Powder

PTEROCARPUS SANTALINUS WOOD POWDER

3.8

Red sandalwood powder is a gentle botanical ingredient that can help soothe skin and provide mild antioxidant benefits, but its effectiveness depends on formulation and particle size.

Irritation

low

Source

natural

beautyskincarebotanical
Read ingredient review

Antioxidant

Red Seaweed Extract

Polysiphonia lanosa extract

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Red Water Lily Flower Extract

NYMPHAEA RUBRA FLOWER EXTRACT

3.8

A gentle, antioxidant-rich flower extract that may help calm skin and fight free radical damage, though research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Red Yeast Rice & Yam Ferment

Monascus/ Dioscorea Japonica Root Ferment Extract Filtrate

3.8

A fermented botanical complex that may offer antioxidant benefits, but research is still early and benefits are not yet proven in human skin.

Irritation

low

Source

biotech

beautyskincareantioxidant
Read ingredient review

Antioxidant

Red Yeast Rice Ferment

Monascus/Oryza Sativa Ferment

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Redbud Flower Extract

Cercis Chinensis Flower/Leaf/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
Read ingredient review

Antioxidant

Redwood Leaf Cell Extract

Sequoia Sempervirens Leaf Cell Extract

3.8

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

Irritation

low

Source

biotech

beautyskincareantioxidant
Read ingredient review

Antioxidant

Rehmannia Root Extract

Rehmannia Glutinosa Root Extract

3.8

A gentle herbal extract with antioxidant and soothing potential, but human skin research is still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Soothing agent

Rehmannia Root Ferment Extract

SACCHAROMYCES/REHMANNIA GLUTINOSA ROOT FERMENT EXTRACT

4.0

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

Irritation

low

Source

biotech

beautyskincaresoothing agent
Read ingredient review

Antioxidant

Reindeer Lichen Extract

MESOPHYLLUM LICHENOIDES EXTRACT

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Soothing Agent

Reindeer Moss Extract

CLADONIA RANGIFERINA EXTRACT

3.8

A gentle, natural extract that may help calm skin and fight environmental stress, but research is still early.

Irritation

low

Source

natural

beautyskincaresoothing
Read ingredient review

Antioxidant

Reishi & Apple Ferment Extract

Ganoderma Amboinense (Mushroom)/Apple Ferment Extract Filtrate

4.0

A gentle fermented blend that may help soothe and protect the skin, but research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Reishi & Bellflower Root Ferment

Ganoderma Lucidum/Platycodon Grandiflorus Root Ferment Extract Filtrate

4.0

A fermented botanical blend that may help calm and protect skin, though research is still early.

Irritation

low

Source

biotech

beautyskincareantioxidant
Read ingredient review

Antioxidant

Reishi & Hovenia Ferment Extract

Ganoderma Lucidum (Reishi) / Hovenia Dulcis Branch/Stem Extract Ferment Mycelium Extract

4.0

A gentle fermented botanical blend that may help calm skin and fight environmental stress, though human studies are limited.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Reishi & Willow Ferment Extract

Ganoderma Lucidum/Salix Gracilistyla Leaf/Stem Ferment Extract Filtrate

4.0

A gentle, fermented botanical blend that may help calm skin and defend against environmental stress, though research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Reishi & Willow Stem Ferment

Ganoderma Lucidum/Salix Gracilistyla Stem Ferment Extract Filtrate

4.0

A fermented botanical blend that may help calm skin and defend against environmental stress, though research is still early.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Reishi Ferment Filtrate

Ganoderma Lucidum Ferment Filtrate

4.0

A fermented reishi mushroom extract that helps calm skin and defend against environmental stress.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Reishi Mushroom Extract

Ganoderma Neo-Japonicum Fruiting Body Extract

4.0

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Reishi Mushroom Stem Extract

Ganoderma Lucidum Stem Extract

4.0

A gentle, antioxidant-rich mushroom extract that helps calm skin and defend against environmental stress—great for sensitive or aging skin.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Reishi Mushroom Stem Powder

Ganoderma Lucidum Stem Powder

3.8

A gentle, antioxidant-rich mushroom powder that may help calm skin and fight free radicals, but research on its topical benefits is still early.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

Antioxidant

Resacetophenone

Resacetophenone

3.8

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

Irritation

low

Source

synthetic

beautyskincareantioxidant
Read ingredient review

Exfoliant

Resorcinol

Resorcinol

3.5

Resorcinol is an effective exfoliant and antiseptic for acne and dark spots, but it can be irritating and is not suitable for sensitive skin or during pregnancy.

Irritation

moderate

Source

synthetic

beautyskincareexfoliant
Read ingredient review

Exfoliant

Resorcinol Acetate

RESORCINOL ACETATE

3.8

A milder cousin of resorcinol that helps fade dark spots and smooth skin texture, but can still cause irritation in sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincareexfoliant
Read ingredient review

Skin lightening agent

Resorcinol Bis-Ethylhexanoate

RESORCINOL BIS-ETHYLHEXANOATE

3.8

A synthetic brightener that helps fade dark spots and even skin tone with low irritation risk.

Irritation

low

Source

synthetic

beautyskincarebrightening agent
Read ingredient review

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
Read ingredient review

Fragrance Ingredient

Resorcinol Dimethyl Ether

Resorcinol Dimethyl Ether

3.5

A synthetic fragrance ingredient with a pleasant, sweet, clove-like scent; generally considered safe at low concentrations but offers no direct skincare benefit.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Skin-lightening agent

Resorcinol Dipentyl Ether

RESORCINOL DIPENTYL ETHER

3.5

A synthetic brightener that targets dark spots, but may cause irritation for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincareskin-lightening agent
Read ingredient review

Soothing Agent

Restharrow Root Extract

Ononis Arvensis Root Extract

3.8

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

Irritation

low

Source

natural

beautyskincarebotanical extract
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

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

beautyskincareantioxidant
Read ingredient review

Cell-communicating ingredient

Retinal

Retinal

4.5

Retinal is a highly effective retinoid that works faster than retinol but may cause more irritation, making it best for experienced users seeking visible anti-aging results.

Irritation

moderate

Source

semi-synthetic

beautyskincareanti-aging
Read ingredient review

Cell-communicating ingredient

Retinol

Retinol

4.5

Retinol is a gold-standard anti-aging ingredient that speeds up skin renewal but can cause irritation if not introduced gradually.

Irritation

moderate

Source

semi-synthetic

beautyskincareactive
Read ingredient review

Cell-communicating ingredient

Retinol Yeast Ferment Complex

Retinol, Saccharomyces Polypeptide

4.0

A retinol-peptide hybrid that aims to smooth fine lines and improve texture with a gentler touch than plain retinol.

Irritation

moderate

Source

semi-synthetic

beautyskincareactive
Read ingredient review

Anti-Aging Agent

Retinoxytrimethylsilane

Retinoxytrimethylsilane

4.0

A gentler, more stable version of retinol that can help smooth fine lines and improve skin texture with less irritation.

Irritation

low

Source

semi-synthetic

beautyskincareanti-aging
Read ingredient review