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

Fragrance Ingredient

Methyl Oxaspiro Undecanol

4-METHYL-1-OXASPIRO-4-UNDECANOL

3.5

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

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance ingredient

Methyl Oxaspirodecane

TRANS-8-METHYL-1-OXASPIRODECANONE

3.8

A synthetic scent ingredient that adds a pleasant, subtle note to products but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl Oxopentenylcyclopentaneacetate

METHYL 3-OXO-2-PENTENYLCYCLOPENTANEACETATE

3.5

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

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl p-Anisate

METHYL P-ANISATE

3.8

A gentle, plant-derived fragrance ingredient that adds a sweet, anise-like scent to products with minimal irritation risk.

Irritation

low

Source

natural

beautyskincarefragrance
Read ingredient review

Emollient

Methyl Palmate

METHYL PALMATE

3.8

Methyl Palmate is a gentle, plant-derived emollient that softens skin and helps other ingredients spread smoothly, but its palm oil origin raises sustainability concerns.

Irritation

low

Source

natural

beautyskincareemollient
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Emollient

Methyl Palmitate

Methyl Palmitate

3.8

Methyl Palmitate is a gentle emollient that softens skin, but may clog pores for acne-prone individuals.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Fragrance

Methyl Pelargonate

Methyl Pelargonate

3.8

Methyl Pelargonate is a mild synthetic ester that adds a subtle fruity scent and light emollient feel, but it offers no active skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Solvent

Methyl Pentanol

4-METHYLPENTAN-2-OL

3.5

A functional solvent that helps products spread and feel lighter, but may cause irritation in sensitive individuals at high concentrations.

Irritation

moderate

Source

synthetic

beautyskincaresolvent
Read ingredient review

Fragrance

Methyl Pentenone

4-METHYLPENT-3-EN-2-ONE

3.5

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

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Solvent

Methyl Perfluorobutyl Ether

Methyl Perfluorobutyl Ether (and) Methyl Perfluoroisobutyl Ether

3.8

A fast-drying, non-greasy fluid that helps products spread smoothly and feel lightweight on skin.

Irritation

low

Source

synthetic

beautyskincaresolvent
Read ingredient review

Solvent

Methyl Perfluoroisobutyl Ether

Methyl Perfluoroisobutyl Ether

3.5

A fast-evaporating synthetic fluid that helps products spread smoothly and feel weightless, but its environmental persistence raises concerns.

Irritation

low

Source

synthetic

beautyskincaresolvent
Read ingredient review

Fragrance

Methyl Phenethyl Ether

METHYL PHENETHYL ETHER

3.5

Methyl phenethyl ether is a synthetic fragrance ingredient that adds a floral, honey-like scent to products; it is generally considered safe at low levels but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl Phenyl Hexanone

5-METHYL-5-PHENYL-3-HEXANONE

3.5

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

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl Phenyl Hexene Epoxide

3-METHYL-1-PHENYL-3-HEXENE 1,5-EPOXIDE

3.5

A synthetic fragrance compound that adds a pleasant floral-green note but offers no skincare benefit and may be unnecessary for sensitive skin.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl Phenyl Pentanone

4-METHYL-4-PHENYL-2-PENTANONE

3.5

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

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance component

Methyl Phenylpropionate

METHYL PHENYLPROPIONATE

3.5

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

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl Propionate

METHYL PROPIONATE

3.5

Methyl propionate is a synthetic fragrance ingredient that adds a fruity, rum-like scent to products; it is generally considered safe at low levels but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl Propyl Cyclohexenone

3-METHYL-5-PROPYL-2-CYCLOHEXENONE

3.5

A synthetic scent ingredient that adds a warm, woody note to products but offers no skincare benefit and may be unnecessary for sensitive skin.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl Propyl Diketone

Methyl Propyl Diketone

3.5

A synthetic fragrance ingredient that adds a buttery or caramel-like scent, but may cause skin irritation in sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl Pyrazinyl Ketone

METHYL PYRAZINYL KETONE

3.5

A synthetic scent compound that adds a nutty, roasted aroma to products but offers no skincare benefit beyond fragrance.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Solvent

Methyl Pyrrolidone

METHYL PYRROLIDONE

2.5

Methyl pyrrolidone is a powerful solvent that can help ingredients absorb deeper, but its potential for irritation and safety concerns make it a less preferred choice in modern skincare.

Irritation

moderate

Source

synthetic

beautyskincaresolvent
Read ingredient review

Emollient

Methyl Ricinoleate

METHYL RICINOLEATE

3.8

A gentle, castor-oil-derived emollient that softens skin without feeling greasy, but it's not a powerhouse active ingredient.

Irritation

low

Source

natural

beautyskincareemollient
Read ingredient review

Film Former

Methyl Rosinate

Methyl Rosinate

3.5

A plant-based film former that helps makeup and skincare stay put, especially in water-resistant formulas.

Irritation

low

Source

natural

beautyskincarefilm-former
Read ingredient review

Soothing agent

Methyl Salicylate

Methyl Salicylate

3.5

Methyl salicylate can soothe minor muscle aches and provide a cooling-warming sensation, but it may irritate sensitive skin and should be used cautiously around the face.

Irritation

moderate

Source

natural

beautyskincaresoothing agent
Read ingredient review

Soothing Agent

Methyl Salicylate Glycyrrhetinate

METHYL SALICYLATE GLYCYRRHETINATE

3.8

A gentle, dual-action ingredient that combines cooling and soothing benefits, best for calming irritated or sensitive skin.

Irritation

low

Source

semi-synthetic

beautyskincaresoothing agent
Read ingredient review

Emollient

Methyl Stearate

Methyl Stearate

4.0

A gentle emollient that softens skin and improves product texture without clogging pores.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Emollient

Methyl Stearic Acid

METHYL STEARIC ACID

3.8

A gentle emollient that helps soften and smooth skin without clogging pores, but it's not a standout active ingredient.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emollient

Methyl Sunflowerseedate

Methyl Sunflowerseedate

4.3

A lightweight, non-greasy emollient derived from sunflower oil that hydrates and softens skin with a silky finish.

Irritation

low

Source

natural

beautyskincareemollient
Read ingredient review

Depilatory agent

Methyl Thioglycolate

METHYL THIOGLYCOLATE

2.0

Methyl thioglycolate is a potent chemical that breaks down hair protein, but it can cause skin irritation and burns if misused.

Irritation

high

Source

synthetic

beautyhaircaredepilatory
Read ingredient review

Fragrance Ingredient

Methyl Tiglate

METHYL TIGLATE

3.5

Methyl Tiglate is a synthetic fragrance ingredient that adds a pleasant scent to products but offers no skincare benefits and may trigger sensitivities in some people.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Eyelash Enhancer

Methyl Travoprost

METHYL TRAVOPROST

3.0

Methyl Travoprost is a synthetic prostaglandin analog that can promote eyelash growth, but it carries risks of irritation and potential side effects, including darkening of the eyelid skin and iris color changes.

Irritation

moderate

Source

synthetic

beautyskincareeyelash
Read ingredient review

Skin conditioner

Methyl Trimethicone

Methyl Trimethicone

4.0

A gentle, non-greasy silicone that improves product feel and spreadability without clogging pores.

Irritation

low

Source

synthetic

beautyskincarehaircare
Read ingredient review

Antioxidant

Methyl Tryptophanate HCl

METHYL TRYPTOPHANATE HCL

3.5

A gentle, lab-made amino acid derivative that may help protect skin from environmental stress, but research is still early.

Irritation

low

Source

synthetic

beautyskincareantioxidant
Read ingredient review

Skin brightening agent

Methyl Tyrosinate HCl

METHYL TYROSINATE HCL

3.5

A gentle, synthetic amino acid derivative that may help brighten skin by interfering with melanin production, but clinical evidence is still limited.

Irritation

low

Source

synthetic

beautyskincarebrightening agent
Read ingredient review

Surfactant

Methyl Undecenoyl Leucinate

Methyl Undecenoyl Leucinate

4.5

A mild, amino-acid-based surfactant that cleanses without stripping the skin’s natural moisture barrier.

Irritation

low

Source

semi-synthetic

beautyskincarecleanser
Read ingredient review

Emollient

Methyl Undecylenate

METHYL UNDECYLENATE

3.8

A lightweight emollient ester that softens skin without a greasy feel, generally well-tolerated.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Fragrance Ingredient

Methyl Valerate

Methyl Valerate

3.5

Methyl Valerate is a synthetic fragrance ester that adds a fruity note to products; it is generally safe at low levels but offers no skincare benefit.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Antioxidant

Methyl Vanillate

Methyl Vanillate

4.0

Methyl Vanillate is a gentle antioxidant that helps protect skin from environmental stress while offering a subtle vanilla-like scent.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Fragrance Ingredient

Methyl Vinyl Cyclohexanol

2-METHYL-5-METHYLVINYL-CYCLOHEXANOL

3.5

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

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl Vinyl Cyclohexene Acetate

4-METHYLVINYLCYCLOHEXENE-1-METHYL ACETATE

3.5

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

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl-Methylcyclohexenyl-Heptadiene

METHYL-METHYLCYCLOHEXENYL-HEPTADIENE

3.5

A synthetic fragrance ingredient that adds a pleasant scent but offers no skincare benefits and may cause irritation for sensitive individuals.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Methyl-Methylpropenyloctenone

METHYL-METHYLPROPENYLOCTENONE

3.0

A synthetic fragrance compound that adds scent but offers no skincare benefit and may irritate sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarefragrance
Read ingredient review

Solvent

Methylal

METHYLAL

3.8

Methylal is an effective solvent that helps products spread and dry quickly, but it may cause irritation in sensitive skin and raises mild concerns about formaldehyde release.

Irritation

moderate

Source

synthetic

beautyskincaresolvent
Read ingredient review

Fragrance Ingredient

Methylallyl Angelate

METHYLALLYL ANGELATE

3.5

A synthetic fragrance ingredient that adds scent but offers no skincare benefits; safe at low levels but may cause irritation in sensitive individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Thickener

Methylamido Cellulose Gum

Methylamido Cellulose Gum

3.8

A gentle, plant-derived thickener that improves product texture without common irritation concerns.

Irritation

low

Source

semi-synthetic

beautyskincarethickener
Read ingredient review

Fragrance Ingredient

Methylbenzyl Acetate

METHYLBENZYL ACETATE

3.5

Methylbenzyl Acetate is a common synthetic fragrance component that adds a sweet floral note, but it may cause allergic reactions in sensitive individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Preservative

Methylbenzyl Alcohol

METHYLBENZYL ALCOHOL

3.8

A gentle preservative booster and fragrance component that helps keep products fresh, but may cause mild irritation in very sensitive skin.

Irritation

low

Source

synthetic

beautyskincarepreservativefragrance
Read ingredient review

Fragrance Ingredient

Methylbenzyl Carbinyl Acetate

METHYLBENZYL CARBINYL ACETATE

3.5

A synthetic floral scent ingredient that is generally safe at low levels but may cause sensitivity in those with fragrance allergies.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

UV Filter

Methylbenzylidene Camphor

METHYLENEDIOXYBENZOYL ETHYL PABA

3.5

A synthetic UVB filter that is effective but has limited global approval due to safety concerns.

Irritation

low

Source

synthetic

beautyskincaresunscreen
Read ingredient review

Fragrance Ingredient

Methylbicycloheptylpropyl Acetate

METHYLBICYCLOHEPTYLPROPYL ACETATE

3.5

A synthetic scent ingredient that adds a pleasant aroma but offers no skincare benefits; safe for most people at low levels.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review