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

Decanal

DECANAL

3.5

Decanal is a natural fragrance ingredient that adds a fresh citrus scent to products, but it can be a skin sensitizer for some people.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance Ingredient

Decanal Dimethyl Acetal

DECANAL DIMETHYL ACETAL

3.5

A synthetic fragrance ingredient that adds a fresh scent but offers no skincare benefits and may cause sensitivity in some people.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Decanenitrile

Decanenitrile

3.5

Decanenitrile is a synthetic fragrance ingredient that adds a fresh, citrusy note, but it offers no skincare benefits and may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Delta-Decalactone

DELTA-DECALACTONE

3.5

Delta-Decalactone is a pleasant-smelling fragrance ingredient with a low irritation profile, but it offers no direct skincare benefits beyond scent.

Irritation

low

Source

natural

beautyskincarefragrance
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Fragrance Ingredient

Delta-Dodecalactone

DELTA-DODECALACTONE

3.8

A synthetic scent ingredient that adds a creamy, fruity note to products; generally safe at low levels but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Delta-Hexalactone

DELTA-HEXALACTONE

3.5

A synthetic scent molecule that adds a sweet, creamy note to products; generally safe but offers no skincare benefit.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Delta-Nonalactone

DELTA-NONALACTONE

3.8

Delta-Nonalactone is a synthetic fragrance ingredient that adds a creamy, coconut-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

Delta-Octalactone

DELTA-OCTALACTONE

3.5

Delta-Octalactone is a synthetic fragrance ingredient that adds a creamy, coconut-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

Delta-Undecalactone

DELTA-UNDECALACTONE

3.5

A synthetic scent ingredient that adds a creamy, coconut-like aroma; generally considered safe at low levels but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Deodar Cedar Wood Oil

Cedrus Deodara Wood Oil

3.8

A natural aromatic oil that adds a woody scent to products, but may cause irritation in sensitive skin if used undiluted.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance Ingredient

Diacetyl

DIACETYL

2.5

Diacetyl adds a buttery scent to cosmetics but is controversial due to respiratory risks from inhalation, especially in aerosolized products.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dibenzyl Ether

DIBENZYL ETHER

3.5

Dibenzyl Ether is a synthetic fragrance ingredient that adds a light floral note, but it offers no skincare benefits and may cause sensitivity in those with fragrance allergies.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Dibutyl Sulfide

Dibutyl Sulfide

3.0

Dibutyl Sulfide is a synthetic fragrance ingredient with a strong, unpleasant odor at high concentrations, used in tiny amounts to add complexity to scents.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dibutyldihydrofuranone

Dibutyldihydrofuranone

3.5

A synthetic scent ingredient that adds a sweet, creamy note to products; generally considered safe at low concentrations but offers no skincare benefit.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Didehydromenthane

Didehydromenthane

3.5

Didehydromenthane is a synthetic minty fragrance that can make products smell fresh, but it may cause irritation for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Didehydropinane

Didehydropinane

3.0

Didehydropinane 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

Diethoxybenzaldehyde

3,4-DIETHOXYBENZALDEHYDE

3.5

A synthetic fragrance ingredient with limited safety data; generally considered low risk at typical use levels but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Diethyl Malonate

Diethyl Malonate

3.5

Diethyl Malonate is a synthetic fragrance ingredient that adds a fruity, apple-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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Plasticizer

Diethyl Phthalate

DIETHYL PHTHALATE

2.5

Diethyl Phthalate is a synthetic plasticizer with a controversial safety profile; many brands have voluntarily phased it out due to consumer concerns, though regulatory bodies generally consider it safe at low levels.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Diethyldimethylcyclohexenone

DIETHYLDIMETHYLCYCLOHEXENONE

3.5

A synthetic scent ingredient that adds fragrance but offers no skincare benefits; generally safe at low levels but may cause sensitivity in some people.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Diethylheptadienal

DIETHYLHEPTADIENAL

3.5

Diethylheptadienal is a synthetic fragrance ingredient that adds a fresh scent but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance

Diethylphenyl Methyl Ketone

2,4-DIETHYLPHENYL METHYL KETONE

3.5

A synthetic fragrance ingredient that adds scent but offers no skin benefit; safe at low levels but may cause sensitivity in some people.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Diethylpyrazine

2,3-DIETHYLPYRAZINE

3.5

A synthetic fragrance compound that adds a nutty, roasted note to products; generally safe at low levels but offers no skincare benefit.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Diethylquinoline

DIETHYLQUINOLINE

2.5

Diethylquinoline is a synthetic fragrance compound with limited safety data; it may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance

Dihydro Pentamethylindanone

Dihydro Pentamethylindanone

3.5

A synthetic scent ingredient that adds a pleasant floral-musky note, but offers no skincare benefits and may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dihydro-4-Methyl-5-Pentylfuranone

DIHYDRO-4-METHYL-5-PENTYLFURANONE

3.5

A synthetic fragrance ingredient that adds a sweet, creamy scent but offers no skincare benefits and may be a concern for those with fragrance sensitivities.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dihydro-Alpha-Methyl Alpha-Ionone

DIHYDRO-ALPHA-METHYL ALPHA-IONONE

3.5

A synthetic scent ingredient that adds a pleasant floral-woody note but offers no skincare benefit and may be a concern for those with fragrance sensitivities.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Dihydro-Alpha-Terpineol

Dihydro-Alpha-Terpineol

3.5

A synthetic pine-scented fragrance ingredient that adds a fresh note but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dihydroanethole

DIHYDROANETHOLE

3.5

Dihydroanethole is a synthetic scent ingredient that adds a sweet, licorice-like note but offers no skin benefit and may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Dihydrocarveol

DIHYDROCARVEOL

3.5

Dihydrocarveol adds a minty, herbal scent to products but may cause irritation in sensitive individuals at higher concentrations.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Dihydrocarvone

DIHYDROCARVONE

3.5

Dihydrocarvone is a natural fragrance compound that adds a minty scent to products but offers no direct skincare benefits.

Irritation

low

Source

natural

beautyskincarefragrance
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Fragrance Ingredient

Dihydrocitronellyl Acetate

DIHYDROCITRONELLYL ACETATE

3.5

A synthetic scent ingredient that makes products smell pleasant but offers no skincare benefit and may trigger sensitivity in some people.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance ingredient

Dihydrocitronellyl Butyrate

DIHYDROCITRONELLYL BUTYRATE

3.8

A synthetic fragrance ester that adds a pleasant scent but offers no skincare benefits; safe at low concentrations for most people.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dihydrocitronellyl Ethyl Ether

DIHYDROCITRONELLYLETHYL ETHER

3.8

A synthetic scent ingredient that adds a pleasant floral note but offers no skincare benefits and may cause sensitivity in some people.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Dihydrofarnesol

Dihydrofarnesol

4.0

Dihydrofarnesol is a gentle, naturally derived fragrance ingredient that also offers mild skin-conditioning benefits, making it a safer alternative to synthetic perfumes.

Irritation

low

Source

natural

beautyskincarefragrance
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Fragrance Ingredient

Dihydrogeranial Diphenethyl Acetal

Dihydrogeranial Diphenethyl Acetal

3.5

A synthetic fragrance ingredient that adds a long-lasting scent to products; generally considered safe at low concentrations but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance ingredient

Dihydrogeranyl Isovalerate

DIHYDROGERANYL ISOVALERATE

3.5

A synthetic scent ingredient that adds a pleasant aroma but offers no skincare benefits; safe at low levels but may cause sensitivity in some.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dihydrogeranyl Tiglate

Dihydrogeranyl Tiglate

4.0

Dihydrogeranyl Tiglate is a synthetic fragrance ingredient that adds a pleasant 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

Dihydrogeranylacetone

Dihydrogeranylacetone

3.5

A synthetic fragrance ingredient that adds a fresh, green scent; generally safe at low levels but may cause irritation in sensitive individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance

Dihydrojasmone

Dihydrojasmone

3.8

Dihydrojasmone is a synthetic jasmine-like fragrance that adds a pleasant scent to products but offers no skincare benefits and may be a concern for those with fragrance sensitivities.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dihydrolinalool

1,2-DIHYDROLINALOOL

3.5

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

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance

Dihydromyrcene

Dihydromyrcene

3.8

Dihydromyrcene is a synthetic scent ingredient that adds a fresh, citrus-like aroma but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dihydromyrcenyl Acetate

DIHYDROMYRCENYL ACETATE

3.5

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

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dihydropseudoionone

DIHYDROPSEUDOIONONE

3.5

Dihydropseudoionone is a synthetic scent ingredient that adds a pleasant floral note, but it offers no skincare benefits and may cause sensitivity in those allergic to fragrance.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dihydroterpinyl Acetate

DIHYDROTERPINYL ACETATE

3.5

Dihydroterpinyl Acetate is a synthetic scent ingredient that gives a fresh, woodsy aroma but may cause irritation in sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Solvent

Diisobutyl Ketone

2,6-DIMETHYL-4-HEPTANONE

2.5

A synthetic solvent used mainly in fragrances; not a primary skincare active and may cause irritation at higher levels.

Irritation

moderate

Source

synthetic

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Fragrance Ingredient

Diisopropyl Benzaldehyde

DIISOPROPYL BENZALDEHYDE

3.5

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

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance

Dill Herb Oil

Anethum Graveolens Herb Oil

3.8

Dill Herb Oil adds a fresh herbal scent and mild antimicrobial benefits, but can be irritating for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Dill Seed Oil

Anethum Graveolens Seed Oil

3.5

Dill Seed Oil adds a fresh, herbal scent to skincare products and may offer mild antioxidant benefits, but it can be irritating for sensitive skin and is mainly used for fragrance.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance Ingredient

Dimethoxybenzyl Alcohol

Dimethoxybenzyl Alcohol

4.0

A mild synthetic fragrance ingredient that also helps preserve formulas, generally considered safe at low concentrations.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dimethyl Benzenebutanol

Dimethyl Benzenebutanol

3.5

A synthetic fragrance ingredient that adds a pleasant floral scent but offers no skincare benefits and may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dimethyl Cyclohexene Carbaldehyde

DIMETHYL-3-CYCLOHEXENE-1-CARBALDEHYDE

3.5

A synthetic fragrance component that provides a pleasant scent but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

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Fragrance Ingredient

Dimethyl Cyclohexene Carboxaldehyde

2,4-DIMETHYL-3-CYCLOHEXENE CARBOXALDEHYDE

3.5

A synthetic scent ingredient that adds a fresh, citrus note but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dimethyl Cyclohexenecarbonitrile

2,4-DIMETHYL CYCLOHEXENECARBONITRILE

3.5

A synthetic scent ingredient that adds a fresh, citrus note but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dimethyl Dioxaspiro Undecane

3,3-DIMETHYL-1,5-DIOXASPIRO-UNDECANE

3.8

A synthetic scent ingredient that adds a fresh, green note to products; generally safe at low levels but may cause sensitivity in some.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Dimethyl Hexenyl Dihydrofuranone

DIMETHYL-4-HEXENYL-DIHYDROFURANONE

3.5

A synthetic fragrance compound that adds scent but offers no skincare benefits; safe at low levels but may irritate sensitive skin.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review