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 20,303
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

Bulking Agent

Wollastonite

WOLLASTONITE

2.5

Wollastonite is a natural mineral used mainly as a filler and texture modifier in powder cosmetics, but it has limited skincare benefits and its safety in inhaled forms is a concern.

Irritation

low

Source

natural

beautyskincaretexturizer
Read ingredient review

Humectant

Wood Ear Mushroom Extract

AURICULARIA POLYTRICHA FRUITING BODY EXTRACT

4.0

A gentle, hydrating mushroom extract that helps skin retain moisture and may calm irritation, though research is still emerging.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Antioxidant

Wood Sorrel Extract

Oxalis Acetosella Extract

3.8

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

Irritation

low

Source

natural

beautyskincarebotanical extract
Read ingredient review

Humectant

Wool Cuticle Amino Acids

Wool Cuticle Amino Acids

4.0

A gentle, protein-derived humectant that helps hair and skin retain moisture and feel smoother, but may not suit those with wool allergies.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Antioxidant

Woolly Thistle Callus Extract

Cirsium Eriophorum Callus Extract

4.0

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Soothing Agent

Wormwood Extract

Artemisia Absinthium Herb Extract

3.8

A gentle botanical extract with antioxidant and soothing potential, but research in skincare is still limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
Read ingredient review

Antimicrobial

Wormwood Oil

Artemisia Absinthium Herb Oil

3.5

Wormwood oil offers antimicrobial and soothing benefits but can be irritating for sensitive skin and requires careful dilution.

Irritation

moderate

Source

natural

beautyskincareessential oil
Read ingredient review

Soothing agent

Wrightia Tinctoria Leaf Oil

WRIGHTIA TINCTORIA LEAF OIL

3.8

A gentle, plant-based oil with traditional roots in soothing skin, but modern research is still limited.

Irritation

low

Source

natural

beautyskincaresoothing agent
Read ingredient review

Thickener

Xanthan Gum

Xanthan Gum

4.5

Xanthan gum is a safe, plant-derived thickener that gives your skincare products a smooth, spreadable texture without clogging pores.

Irritation

low

Source

natural

beautyskincarethickener
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Viscosity Controlling

Xanthan Gum Crosspolymer

XANTHAN GUM CROSSPOLYMER

4.0

A gentle, effective thickener that improves product texture without clogging pores or irritating skin.

Irritation

low

Source

biotech

beautyskincarethickener
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Antioxidant

Xanthine

Xanthine

3.5

Xanthine is a gentle antioxidant that may help calm skin and fight free radicals, but it's not a powerhouse ingredient on its own.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Xanthohumol

Xanthohumol

4.0

A promising hop-derived antioxidant that helps defend skin from pollution and UV damage, though more human studies are needed to confirm its anti-aging benefits.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Colorant

Xenotime

Xenotime

2.0

Xenotime is a rare mineral used mainly as a colorant in cosmetics; there is very little research on its skincare benefits or safety.

Irritation

low

Source

natural

beautyskincarecolorant
Read ingredient review

Emollient

Ximenia Americana Oil PEG-8 Esters

XIMENIA AMERICANA SEED OIL PEG-8 ESTERS

4.0

A gentle, semi-synthetic emollient that helps soften skin and improve product texture, with low irritation potential.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Antioxidant

Xylaria Nigripes Ferment Filtrate

Xylaria Nigripes Ferment Filtrate

3.8

A gentle, antioxidant-rich fungal ferment that may help calm skin and defend against environmental stress, though human research is still limited.

Irritation

low

Source

biotech

beautyskincareantioxidant
Read ingredient review

Emulsifier

Xylitan Caprylate

Xylitan Caprylate

4.3

A mild, plant-derived emulsifier that helps create stable, creamy textures while being very gentle on skin.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emollient

Xylitan Sesquicaprylate

Xylitan Sesquicaprylate

4.0

A gentle, sugar-derived emollient that helps products spread smoothly and leaves skin feeling soft without greasiness.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Humectant

Xylitol

Xylitol

4.0

Xylitol is a gentle humectant that helps hydrate the skin and may support a healthy skin barrier without clogging pores.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Emollient

Xylityl Cocoate

Xylityl Cocoate

4.5

Xylityl Cocoate is a mild, sugar-based emollient that hydrates and softens skin without clogging pores, making it a great choice for sensitive and acne-prone skin.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Humectant

Xylityl Phosphate

Xylityl Phosphate

4.0

A gentle, sugar-derived humectant that hydrates without stickiness and may help strengthen the skin barrier.

Irritation

low

Source

semi-synthetic

beautyskincarehumectant
Read ingredient review

Emollient

Xylityl Sesquicaprylate

Xylityl Sesquicaprylate

4.0

A gentle, lightweight emollient that hydrates and helps control odor-causing bacteria, making it a smart choice for sensitive or acne-prone skin.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Humectant

Xylitylglucoside

Xylitylglucoside

4.3

A gentle, sugar-derived humectant that boosts skin hydration without stickiness, ideal for sensitive and dry skin types.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Humectant

Xylobiose

XYLOBIOSE

4.0

Xylobiose is a gentle, plant-derived sugar that hydrates and supports beneficial skin bacteria, making it a promising prebiotic humectant for sensitive skin.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Humectant

Xyloglucan

Xyloglucan

4.3

Xyloglucan is a gentle, plant-based humectant that hydrates and soothes the skin while forming a protective barrier — a great option for sensitive or dry skin types.

Irritation

low

Source

natural

beautyskincarehumectantfilm former
Read ingredient review

Humectant

Xylose

XYLOSE

4.0

Xylose is a gentle, natural humectant that helps hydrate the skin and may support collagen production, making it a good choice for dry or aging skin.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Emollient

Xylyl Caprate/Caprylate

XYLITYL CAPRATE/CAPRYLATE

4.0

A gentle, plant-derived emollient that hydrates and softens skin without clogging pores, making it a great option for sensitive and acne-prone skin types.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Antioxidant

Xylyl Dibutylbenzofuranone

XYLYL DIBUTYLBENZOFURANONE

4.0

A synthetic antioxidant that helps keep skincare products fresh and stable, with low irritation potential.

Irritation

low

Source

synthetic

beautyskincareantioxidant
Read ingredient review

Antioxidant

Xymenynic Acid

XYMENYNIC ACID

3.5

Xymenynic acid is a plant-derived fatty acid with antioxidant potential, but research is still early and it's not a mainstream ingredient.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Moisturizer

Yak Milk

YAK MILK

3.8

Yak milk is a gentle, nutrient-rich moisturizer that may soothe and soften skin, but research on its cosmetic benefits is still emerging.

Irritation

low

Source

natural

beautyskincaremoisturizer
Read ingredient review

Soothing Agent

Yarrow Extract

Achillea Millefolium Flower/Leaf/Stem Extract

4.0

Yarrow extract is a gentle botanical that may help calm redness and provide antioxidant protection, but its effects are mild and best for sensitive or normal skin types.

Irritation

low

Source

natural

beautyskincarebotanical extract
Read ingredient review

Soothing agent

Yarrow Flower Water

ACHILLEA MILLEFOLIUM FLOWER WATER

3.8

Yarrow flower water is a mild, soothing botanical water that may help calm irritated skin and provide gentle astringent benefits, but research on its cosmetic efficacy is limited.

Irritation

low

Source

natural

beautyskincaresoothing agent
Read ingredient review

Soothing Agent

Yarrow Juice

ACHILLEA MILLEFOLIUM FLOWER/LEAF/STEM JUICE

4.0

Yarrow juice is a gentle, plant-based ingredient that helps calm redness and provides antioxidant protection, making it a good choice for sensitive or irritated skin.

Irritation

low

Source

natural

beautyskincaresoothing agent
Read ingredient review

Antioxidant

Yeast & Mistletoe Ferment Extract

SACCHAROMYCES/VISCUM ALBUM FERMENT EXTRACT

3.8

A fermented blend of yeast and mistletoe that may offer antioxidant and soothing benefits, but research is still emerging.

Irritation

low

Source

biotech

beautyskincareantioxidant
Read ingredient review

Skin conditioning agent

Yeast & Mother of Pearl Ferment

SACCHAROMYCES/MOTHER OF PEARL FERMENT LYSATE FILTRATE

4.0

A gentle fermented ingredient that may help improve skin texture and glow, but research is still limited.

Irritation

low

Source

biotech

beautyskincareconditioning agent
Read ingredient review

Humectant

Yeast & Potato Ferment Filtrate

Saccharomyces/Potato Extract Ferment Filtrate

4.0

A gentle, fermented ingredient that may help hydrate and soothe skin, but evidence is limited to lab studies.

Irritation

low

Source

biotech

beautyskincarehumectant
Read ingredient review

Skin conditioning agent

Yeast and Placenta Ferment

SACCHAROMYCES/HORSE PLACENTA FERMENT FILTRATE

3.5

A fermented ingredient that may support skin hydration and texture, but human research is limited and ethical sourcing is a concern.

Irritation

low

Source

biotech

beautyskincareconditioning agent
Read ingredient review

Antioxidant

Yeast Chromium Ferment Filtrate

Saccharomyces/Chromium Ferment Extract Filtrate

3.8

A novel fermented ingredient with potential antioxidant benefits, but research is limited and it's not a proven skincare powerhouse.

Irritation

low

Source

biotech

beautyskincareantioxidant
Read ingredient review

Humectant

Yeast Collagen Ferment Filtrate

SACCHAROMYCES/HYDROLYZED COLLAGEN/SUCROSE FERMENT FILTRATE

4.0

A fermented blend that may help hydrate and smooth skin, but research is limited and benefits likely come from the whole formulation.

Irritation

low

Source

biotech

beautyskincarehumectant
Read ingredient review

Humectant

Yeast Extract

YEAST EXTRACT

4.0

Yeast extract is a gentle, nutrient-rich ingredient that helps hydrate and condition the skin, but it's not a miracle cure for aging or acne.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Skin conditioning agent

Yeast Ferment Extract

SACCHAROMYCES/CALCIUM/GERMANIUM FERMENT LYSATE EXTRACT

3.8

A gentle, mineral-rich yeast ferment that may help hydrate and condition skin, but research is limited.

Irritation

low

Source

biotech

beautyskincareconditioning agent
Read ingredient review

Humectant

Yeast Ferment Filtrate

SACCHAROMYCES/POTASSIUM FERMENT HYDROLYSATE

4.3

A gentle, fermented yeast ingredient that helps hydrate and condition the skin, popular in K-beauty essences.

Irritation

low

Source

biotech

beautyskincarehumectant
Read ingredient review

Humectant

Yeast Ferment Lysate

SACCHAROMYCES/POTASSIUM FERMENT LYSATE FILTRATE

4.3

A gentle, fermented ingredient that helps hydrate and support a healthy-looking skin barrier without irritation.

Irritation

low

Source

biotech

beautyskincarehumectant
Read ingredient review

Humectant

Yeast Fermented Artichoke Extract

SACCHAROMYCES/HYDROLYZED STACHYS AFFINIS TUBER FERMENT FILTRATE

4.0

A gentle, fermented botanical extract that helps hydrate and protect the skin with antioxidant benefits.

Irritation

low

Source

biotech

beautyskincarehumectantantioxidant
Read ingredient review

Soothing Agent

Yeast Fermented Artichoke Tuber Extract

Saccharomyces/Hydrolyzed Stachys Affinis Tuber Ferment Extract

4.0

A gentle, fermented botanical extract that may help calm irritation and support skin hydration, though research is still early.

Irritation

low

Source

biotech

beautyskincaresoothing agent
Read ingredient review

Humectant

Yeast Magnesium Ferment

Saccharomyces/Magnesium Ferment Lysate Filtrate

4.0

A gentle, fermented yeast ingredient that delivers magnesium to help hydrate and strengthen the skin barrier.

Irritation

low

Source

biotech

beautyskincarehumectant
Read ingredient review

Humectant

Yeast Niacinamide Ferment

Saccharomyces/Niacinamide Ferment Lysate Filtrate

4.0

A gentle, biotech-derived ingredient that pairs yeast ferment with niacinamide to help hydrate, soothe, and support a healthy-looking skin barrier.

Irritation

low

Source

biotech

beautyskincarehumectantsoothing
Read ingredient review

Anti-aging agent

Yeast Peptide Complex

R-SACCHAROMYCES POLYPEPTIDE-1, HEXAPEPTIDE-40, HEXAPEPTIDE-41, SH-OLIGOPEPTIDE-1

4.0

A promising peptide blend that may help firm skin and soften fine lines, but more human studies are needed to confirm its effects.

Irritation

low

Source

mixed

beautyskincareanti-aging
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Humectant

Yeast Peptide Ferment Filtrate

Saccharomyces/Hexapeptide-11 Ferment Filtrate Extract

4.0

A gentle, biotech-derived ingredient that pairs yeast fermentation with a peptide to support skin hydration and barrier function.

Irritation

low

Source

biotech

beautyskincarehumectantconditioning agent
Read ingredient review

Antioxidant

Yeast Titanium Ferment Filtrate

SACCHAROMYCES/TITANIUM CITRATE FERMENT LYSATE FILTRATE

3.8

A novel fermented ingredient that may offer antioxidant protection, but research is still early.

Irritation

low

Source

biotech

beautyskincareantioxidant
Read ingredient review

Skin conditioning agent

Yeast Wheat Germ Ferment

SACCHAROMYCES/WHEAT GERM FERMENT FILTRATE

4.0

A gentle, fermented ingredient that may help support skin barrier function and hydration, but more human studies are needed.

Irritation

low

Source

biotech

beautyskincareconditioning agent
Read ingredient review

Antioxidant

Yeddo Hawthorn Bark Extract

Rhaphiolepis Umbellata Bark 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
Read ingredient review

Antioxidant

Yeddo Hawthorn Stem Extract

Rhaphiolepis Umbellata Stem Extract

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Colorant

Yellow 5 Lake

CI 21108

3.5

A widely used synthetic yellow pigment that adds color to cosmetics but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarecolorant
Read ingredient review

Colorant

Yellow 6 (CI 15985)

CI 15985

3.5

A widely used synthetic colorant that adds yellow-orange shades to cosmetics, generally considered safe in approved concentrations but may cause reactions in sensitive individuals.

Irritation

low

Source

synthetic

beautyskincarecolorant
Read ingredient review

Colorant

Yellow 7 (CI 45350)

CI 45350

3.5

CI 45350 is a synthetic yellow dye that adds color to cosmetics; it is generally considered safe at low concentrations but may cause irritation in sensitive individuals.

Irritation

low

Source

synthetic

beautyskincarecolorant
Read ingredient review

Colorant

Yellow 7 Lake

CI 21100

3.0

A common synthetic pigment that adds yellow color to makeup and bath products, generally considered safe for topical use.

Irritation

low

Source

synthetic

beautyskincarecolorant
Read ingredient review