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

Fragrance Ingredient

Isobutyl Isovalerate

Isobutyl Isovalerate

3.5

A synthetic fragrance ester that adds a fruity, apple-like scent; generally considered safe at low concentrations but offers no skincare benefit.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Isobutyl Linalool

ISOBUTYL LINALOOL

3.5

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

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Emollient

Isobutyl Meadowfoamate

Isobutyl Meadowfoamate

4.3

A silky, non-greasy emollient derived from meadowfoam seed oil that spreads easily and leaves skin feeling smooth without clogging pores.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Film Former

Isobutyl Methacrylate

ISOBUTYL METHACRYLATE

3.5

A synthetic film-former mainly found in nail products; generally safe for nails but may cause irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefilm-former
Read ingredient review

Fragrance Ingredient

Isobutyl Methoxypyrazine

ISOBUTYL-METHOXYPYRAZINE

3.5

A synthetic scent molecule that adds a fresh, green note to products but offers no skincare benefit.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Isobutyl Methyl Tetrahydropyranol

ISOBUTYL METHYL TETRAHYDROPYRANOL

3.5

A synthetic scent ingredient that adds a fresh floral note but offers no skincare benefit and may be unnecessary for sensitive skin.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

UV Absorber

Isobutyl Methylaminobenzoate

ISOBUTYL METHYLAMINOBENZOATE

3.5

A synthetic UVB filter that helps protect skin from sunburn, but its use is limited by regulatory approval in some regions.

Irritation

low

Source

synthetic

beautyskincaresunscreen
Read ingredient review

Emollient

Isobutyl Myristate

Isobutyl Myristate

3.5

A lightweight synthetic emollient that makes products feel silky, but may clog pores for acne-prone skin.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isobutyl Palmitate

Isobutyl Palmitate

3.5

A lightweight synthetic emollient that softens skin but may clog pores for some people.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isobutyl Pelargonate

ISOBUTYL PELARGONATE

4.0

A lightweight synthetic ester that softens skin without feeling greasy, with a low risk of irritation or clogged pores.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Fragrance ingredient

Isobutyl Phenylacetate

ISOBUTYL PHENYLACETATE

4.0

A synthetic fragrance ester that adds a sweet, honey-like scent; generally considered safe at low concentrations but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Depigmenting Agent

Isobutyl Phenylhydrazinoyl Methanesulfonamide

ISOBUTYL PHENYLHYDRAZINOYL METHANESULFONAMIDE

3.0

A synthetic depigmenting ingredient with limited research; may help fade dark spots but requires caution due to potential irritation and lack of long-term safety data.

Irritation

moderate

Source

synthetic

beautyskincaredepigmenting agent
Read ingredient review

Fragrance Ingredient

Isobutyl Propionate

Isobutyl Propionate

3.5

Isobutyl Propionate is a synthetic ester used for its fruity scent in cosmetics; it is generally considered safe at low concentrations but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Isobutyl Quinoline

6-ISOBUTYLQUINOLINE

3.5

A synthetic fragrance ingredient that adds a unique scent but offers no skincare benefits; safe at low concentrations but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Emollient

Isobutyl Ricinoleate

ISOBUTYL RICINOLEATE

4.0

A gentle, non-greasy emollient that softens skin and helps other ingredients spread smoothly.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Fragrance Ingredient

Isobutyl Salicylate

Isobutyl Salicylate

3.5

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

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Emollient

Isobutyl Stearate

ISOBUTYL STEARATE

3.5

A lightweight synthetic emollient that softens skin but may clog pores for some people.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isobutyl Tallowate

ISOBUTYL TALLOWATE

3.5

Isobutyl Tallowate is a semi-synthetic emollient that softens skin but may be comedogenic for acne-prone individuals.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Fragrance

Isobutyl Tiglate

ISOBUTYL TIGLATE

3.5

Isobutyl Tiglate is a synthetic fragrance ingredient that adds a sweet, fruity scent to products; it is generally considered safe at low levels but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Tyrosinase Inhibitor

Isobutylamido Thiazolyl Resorcinol

ISOBUTYLAMIDO THIAZOLYL RESORCINOL

4.3

A well-researched synthetic brightener that targets dark spots by blocking a key enzyme in melanin production, with good tolerability.

Irritation

low

Source

synthetic

beautyskincarebrightening agent
Read ingredient review

Emollient

Isobutylated Lanolin Oil

ISOBUTYLATED LANOLIN OIL

3.5

A modified lanolin oil that moisturizes and smooths skin, but may clog pores for some people.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Film Former

Isobutylene/MA Copolymer

ISOBUTYLENE/MA COPOLYMER

4.0

A safe, synthetic film-former that helps makeup and skincare stay put without clogging pores or irritating skin.

Irritation

low

Source

synthetic

beautyskincarefilm-former
Read ingredient review

Preservative

Isobutylparaben

Isobutylparaben

3.0

Isobutylparaben is an effective preservative but has raised safety concerns due to potential hormone-mimicking effects, leading many brands to phase it out.

Irritation

low

Source

synthetic

beautyskincarepreservative
Read ingredient review

Fragrance Ingredient

Isobutylquinoline Isomers

ISOBUTYLQUINOLINE ISOMERS

3.5

A synthetic scent ingredient that adds a leathery note but may cause irritation for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Skin brightener

Isobutylresorcinol

4-ISOBUTYLRESORCINOL

4.0

A synthetic brightener that targets dark spots by blocking a key enzyme in melanin production, but may cause irritation for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarebrightening agent
Read ingredient review

Fragrance Ingredient

Isobutylthiazole

ISOBUTYLTHIAZOLE

3.5

Isobutylthiazole is a synthetic fragrance compound that adds a green, nutty, or roasted note to products; it is generally safe at low levels but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Isobutyraldehyde

2-METHYLPROPANAL

3.0

A synthetic fragrance ingredient that adds a sharp, fruity scent but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Isobutyric Acid

ISOBUTYRIC ACID

3.5

Isobutyric acid is a fragrance ingredient and pH adjuster that is generally safe at low levels but can be irritating in high concentrations.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Isocamphenyl Cyclohexanol

Isocamphenyl Cyclohexanol (Mixed Isomers)

3.8

A synthetic fragrance ingredient that adds a warm, woody scent; generally considered safe at low levels but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Isocarvyl Acetate

ISOCARVYL ACETATE

3.5

Isocarvyl acetate is a synthetic fragrance ingredient that adds a fresh, herbal scent to products; it is generally considered safe at low concentrations but may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Emulsifier

Isoceteth-10

ISOCETETH-10

4.0

Isoceteth-10 is a gentle synthetic emulsifier that helps mix oil and water in skincare, with a low risk of irritation or clogged pores.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

Isoceteth-10 Stearate

ISOCETETH-10 STEARATE

3.8

Isoceteth-10 Stearate is a gentle synthetic emulsifier that helps water and oil mix in your creams and lotions, with a low risk of irritation.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

Isoceteth-12

ISOCETETH-12

3.5

Isoceteth-12 is a synthetic emulsifier that helps mix oil and water in cleansers, but it may be slightly drying or irritating for very sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Emulsifier

Isoceteth-15

Isoceteth-15

3.5

A reliable emulsifier that helps mix oil and water in creams and lotions, generally well-tolerated but may be less suitable for very sensitive skin.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

Isoceteth-20

ISOCETETH-20

4.0

Isoceteth-20 is a gentle synthetic emulsifier that helps mix water and oil in your skincare, making textures smooth and stable without common irritation.

Irritation

low

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Surfactant

Isoceteth-25

ISOCETETH-25

4.0

Isoceteth-25 is a gentle synthetic emulsifier that helps mix oil and water, making it a common but low-risk ingredient in cleansers and creams.

Irritation

low

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Surfactant

Isoceteth-30

ISOCETETH-30

3.8

Isoceteth-30 is a mild synthetic emulsifier that helps mix water and oil in cleansers, with low irritation potential for most skin types.

Irritation

low

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Surfactant

Isoceteth-5

ISOCETETH-5

3.5

Isoceteth-5 is a gentle synthetic emulsifier that helps mix oil and water in cleansers and lotions, with a low risk of irritation.

Irritation

low

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Emulsifier

Isoceteth-7

Isoceteth-7

3.8

Isoceteth-7 is a gentle synthetic emulsifier that helps mix oil and water in your skincare products, but it may not be ideal for those avoiding ethoxylated ingredients.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

Isoceteth-8 Stearate

ISOCETEARETH-8 STEARATE

3.8

A reliable synthetic emulsifier that helps create stable, creamy textures in skincare, but offers no direct skin benefit.

Irritation

low

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emollient

Isocetyl Alcohol

ISOCETYL ALCOHOL

4.0

Isocetyl alcohol is a gentle, non-drying emollient that helps soften skin and improve product texture without clogging pores.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isocetyl Behenate

Isocetyl Behenate

4.0

A gentle, non-greasy emollient that helps moisturizers feel silky without clogging pores.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isocetyl Ethylhexanoate

Isocetyl Ethylhexanoate

4.0

A lightweight, non-greasy emollient that helps soften skin and improve product texture without clogging pores.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isocetyl Isodecanoate

Isocetyl Isodecanoate

4.0

A lightweight, non-greasy emollient that helps soften skin and improve product texture without clogging pores.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isocetyl Isostearate

Isocetyl Isostearate

4.0

A lightweight, non-greasy emollient that softens skin and helps products spread smoothly.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isocetyl Laurate

Isocetyl Laurate

4.0

Isocetyl Laurate is a lightweight, non-greasy emollient that softens skin and improves product texture with a low risk of irritation or clogged pores.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isocetyl Myristate

Isocetyl Myristate

3.8

Isocetyl Myristate is a reliable emollient that softens skin, but it may clog pores for some people.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isocetyl Palmitate

Isocetyl Palmitate

3.8

A lightweight synthetic emollient that softens skin without a greasy feel, but may clog pores for some people.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isocetyl Salicylate

Isocetyl Salicylate

3.8

Isocetyl Salicylate is a gentle emollient that also offers mild salicylic acid-like benefits, making it a good option for smoothing skin without irritation.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Isocetyl Stearate

Isocetyl Stearate

4.0

A lightweight, non-greasy emollient that helps skin feel soft and smooth without clogging pores.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Antioxidant

Isochrysis Galbana Extract

Isochrysis Galbana Extract

4.0

A gentle marine-sourced extract that helps calm and protect the skin, though research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Soothing Agent

Isocineole

Isocineole

3.8

Isocineole is a gentle, plant-derived compound that may help calm skin and provide a cooling sensation, but research on its cosmetic benefits is still limited.

Irritation

low

Source

natural

beautyskincaresoothing agent
Read ingredient review

Film Former

Isocyanurate Trimer Crosspolymer

HEA/IPDI Isocyanurate Trimer/PG Crosspolymer

3.5

A synthetic film-former that helps makeup last longer and resist water, but may feel tight or stiff on some skin types.

Irritation

low

Source

synthetic

beautyskincarefilm-former
Read ingredient review