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 1,749
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

Fragrance Ingredient

Phenylacetaldehyde Digeranyl Acetal

PHENYLACETALDEHYDE DIGERANYL ACETAL

3.5

A synthetic fragrance ingredient that adds a floral scent; generally safe at low concentrations but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Phenylacetaldehyde Diisoamyl Acetal

PHENYLACETALDEHYDE DIISOAMYL ACETAL

3.5

A synthetic fragrance ingredient that adds pleasant floral notes but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Phenylacetaldehyde Dimethyl Acetal

PHENYLACETALDEHYDE DIMETHYL ACETAL

3.5

A synthetic floral scent ingredient that adds a pleasant hyacinth note but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Phenylacetaldehyde Ethylene Glycol Acetal

PHENYLACETALDEHYDE ETHYLENEGLYCOL CYCLIC ACETAL

3.5

A synthetic floral scent ingredient that can cause skin irritation in sensitive individuals, but is generally safe at low concentrations.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Phenylacetaldehyde Glyceryl Acetal

PHENYLACETALDEHYDE GLYCERYL 1,3-CYCLIC ACETAL

3.8

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

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Phenylacetaldehyde Glyceryl Cyclic Acetals

PHENYLACETALDEHYDE GLYCERYL CYCLIC ACETALS

3.5

A synthetic floral fragrance ingredient that adds scent but offers no skincare benefit and may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Phenylethoxyacetaldehyde

Phenylethoxyacetaldehyde

3.5

A synthetic floral scent ingredient that adds fragrance but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance

Phenylethylpyridine

Phenylethylpyridine

3.5

Phenylethylpyridine is a synthetic fragrance ingredient with limited safety data; it may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance

Phenylhexenone

5-PHENYLHEX-4-EN-2-ONE

3.5

A synthetic fragrance compound that adds a pleasant scent but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Phenylisohexanol

Phenylisohexanol

4.0

A synthetic floral scent ingredient that is generally well-tolerated but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Phenylmethylpentanal

PHENYLMETHYLPENTANAL

3.5

Phenylmethylpentanal is a synthetic fragrance ingredient that adds a floral scent but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance

Phenylpropane

PHENYLPROPANE

3.5

Phenylpropane is a synthetic fragrance ingredient that adds scent but offers no skincare benefits; it may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance

Phenylpropanol

PHENYLPROPANOL

3.8

Phenylpropanol is a mild fragrance ingredient that also helps preserve formulas, but it offers no direct skin benefit.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Phenylpropionaldehyde

PHENYLPROPIONALDEHYDE

3.5

Phenylpropionaldehyde is a synthetic fragrance compound that adds a floral scent but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Phenylpropyl Acetate

1-PHENYLPROPYL ACETATE

3.5

A synthetic fragrance ester that adds a sweet, floral scent to products but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Phenylpropyl Tetrahydrofuran

2-PHENYLPROPYLTETRAHYDROFURAN

3.5

A synthetic scent ingredient that adds a pleasant floral note but offers no skincare benefit and may be a concern for those sensitive to fragrance.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Phoenician Juniper Wood Oil

JUNIPERUS PHOENICEA WOOD OIL RECTIFIED

3.8

A fragrant wood oil with mild antimicrobial potential, best suited for those who enjoy botanical scents and have resilient skin.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Plasticizer

Phthalates

Phthalates

1.5

Phthalates are controversial synthetic chemicals linked to endocrine disruption; most are banned or restricted in cosmetics in many regions, but consumers should still check labels for hidden sources.

Irritation

low

Source

synthetic

beautyskincarefragrancepreservative
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Fragrance

Pimento Berry Oil

Pimenta Officinalis Fruit Oil

3.8

Pimento berry oil adds a warm, spicy scent and offers antioxidant benefits, but its essential oil nature means it can irritate sensitive skin if used too strong.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Pimento Leaf Oil

Pimenta Officinalis Leaf Oil

3.8

Pimento leaf oil adds a warm, spicy scent to products but can be irritating for sensitive skin; it's best used in low concentrations.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Pinanal

PINANAL

3.5

Pinanal is a synthetic pine-scented fragrance ingredient that adds a fresh aroma but offers no skincare benefits and may irritate sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Pinane Carbaldehyde

PINANE CARBALDEHYDE

3.5

Pinane Carbaldehyde is a synthetic fragrance component that adds a pine-like aroma but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Pinanyl Methyl Ketone

Pinanyl Methyl Ketone

3.5

Pinanyl Methyl Ketone is a synthetic scent ingredient that adds a pine-like aroma to products, but it offers no skincare benefits and may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance

Pine Leaf Oil

Pinus Sylvestris Leaf Oil

3.5

Pine leaf oil adds a fresh, woodsy scent to products but can be irritating for sensitive skin and is primarily used for fragrance rather than active skincare benefits.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Pine Leaf/Twig Oil

Pinus Pinaster Leaf/Twig Oil

3.8

A natural essential oil that adds a fresh, woodsy scent to products but may cause irritation in sensitive skin.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Pine Oil

Pinus Palustris Oil

3.8

Pine oil adds a fresh scent and mild antimicrobial benefits, but can be irritating for sensitive skin and may clog pores in high concentrations.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Pine Twig Leaf Oil

Pinus Species Twig Leaf Oil

3.5

Pine twig leaf oil adds a fresh, woodsy scent to products but can be irritating for sensitive skin and is best used at low concentrations.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Pine Twig Oil

Pinus Strobus Twig Oil

3.8

A natural essential oil that adds a fresh pine scent and may offer mild antimicrobial benefits, but can be irritating for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Pinus Lauricio Branch/Leaf Oil

Pinus Lauricio Branch/Leaf Oil

3.5

A fragrant pine oil that adds a fresh scent to products but may cause irritation in sensitive skin due to its essential oil content.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Pinus Lauricio Leaf Oil

Pinus Lauricio Leaf Oil

3.5

A fragrant pine leaf oil with limited research; may offer antimicrobial benefits but poses irritation and sensitivity risks, especially for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarefragrance
Read ingredient review

Fragrance

Piper Malacophyllum Oil

Piper Malacophyllum Flower/Leaf/Stem Oil

3.5

A fragrant essential oil from a tropical pepper plant, used mainly for scent in natural skincare, but with very limited research on skin benefits.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Piper Mollicomum Oil

Piper Mollicomum Flower/Leaf/Stem Oil

3.5

A fragrant plant oil with limited research; best used in low concentrations for its scent rather than proven skincare benefits.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Piperitone

PIPERITONE

3.0

Piperitone is a natural fragrance compound with a minty, camphor-like scent, but it has limited skincare benefits and may cause irritation in sensitive individuals.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance Ingredient

Piperonyl Acetate

PIPERONYL ACETATE

3.5

Piperonyl Acetate is a synthetic fragrance ingredient that adds a sweet, floral scent to products; it is generally considered safe at low concentrations but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Piperonyl Acetone

Piperonyl Acetone

3.5

Piperonyl Acetone is a synthetic fragrance ingredient that adds a pleasant scent but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance

Plumeria Flower Oil

PLUMERIA ALBA FLOWER OIL

3.8

Plumeria flower oil adds a sweet floral scent and mild skin-soothing benefits, but research on its skincare effects is limited.

Irritation

low

Source

natural

beautyskincarefragrance
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Fragrance

Ponderosa Pine Oil

Pinus Ponderosa Branch/Leaf Oil

3.5

Ponderosa pine oil adds a fresh, woodsy scent to products but may irritate sensitive skin and has limited research on skincare benefits.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance Ingredient

Prenyl Acetate

PRENYL ACETATE

3.5

Prenyl acetate is a synthetic fragrance ingredient that adds a fruity, floral note to products, but it offers no skincare benefits and may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Prenyl Benzoate

PRENYL BENZOATE

3.5

Prenyl benzoate is a synthetic fragrance ingredient with a low irritation risk, but it offers no skincare benefits beyond scent.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Propenyl p-Cymene

PROPENYL P-CYMENE

3.5

Propenyl p-Cymene is a synthetic fragrance ingredient that adds scent to products but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Propyl Benzoate

Propyl Benzoate

3.5

Propyl benzoate is a synthetic fragrance ingredient that helps scent and stabilize products, but it offers no direct skin benefit and may be a concern for those avoiding synthetic fragrances.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Propyl Butyrate

Propyl Butyrate

3.8

Propyl Butyrate is a synthetic ester used mainly for its light, fruity scent; it is generally considered safe at low levels but offers no direct skin benefit.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Propyl Phenylacetate

PROPYL PHENYLACETATE

3.5

Propyl Phenylacetate is a synthetic fragrance ingredient that adds a sweet, honey-like scent to products; it is generally considered safe at low concentrations but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Propylidene Phthalide

PROPYLIDENE PHTHALIDE

3.8

A natural fragrance compound from celery seed that adds a warm, spicy scent but offers no direct skincare benefits.

Irritation

low

Source

natural

beautyskincarefragrance
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Fragrance

Pyroligneous Acid Ethyl Esters

PYROLIGNEOUS ACIDS ETHYL ESTERS

3.5

A natural fragrance ingredient with potential antioxidant benefits, but limited research and a moderate risk of skin irritation.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Ravensara Leaf Oil

RAVENSARA AROMATICA LEAF OIL

3.8

Ravensara leaf oil adds a pleasant scent and may offer mild soothing benefits, but it can be irritating for sensitive skin and is best used in low concentrations.

Irritation

moderate

Source

natural

beautyskincarefragrance
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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
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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
Read ingredient review

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
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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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Fragrance

Rocky Mountain Juniper Oil

JUNIPERUS SCOPULORUM LEAF/STEM OIL

3.5

A fragrant essential oil from Rocky Mountain juniper that adds a woodsy scent and may offer mild antioxidant benefits, but can be irritating for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Rosa Rugosa Flower Water

ROSA RUGOSA FLOWER WATER

3.8

A gentle, lightly astringent floral water that can refresh and soothe skin, but its benefits are mostly anecdotal and it may cause sensitivity in those allergic to roses.

Irritation

low

Source

natural

beautyskincaretonerfragrance
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