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

Emulsifier

Propylene Glycol Isodeceth-4

PROPYLENE GLYCOL ISODECETH-4

3.8

A gentle synthetic emulsifier that helps mix water and oil in products, generally well-tolerated by most skin types.

Irritation

low

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Emollient

Propylene Glycol Isostearate

Propylene Glycol Isostearate

3.8

A gentle emollient and emulsifier that helps products feel smooth and spread easily, with a low risk of irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Emollient

Propylene Glycol Laurate

Propylene Glycol Laurate

4.0

A gentle, synthetic emollient that helps soften skin and stabilize formulas without common irritation.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

Emulsifier

Propylene Glycol Laureth-6

PROPYLENE GLYCOL LAURETH-6

3.8

A gentle synthetic emulsifier that helps mix oil and water in cleansers and lotions, generally well-tolerated by most skin types.

Irritation

low

Source

synthetic

beautyskincaresurfactant
Read ingredient review

Emollient

Propylene Glycol Linoleate

Propylene Glycol Linoleate

3.8

A gentle emollient that helps soften skin and improve product texture, but offers no unique benefits over more common alternatives.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Emollient

Propylene Glycol Linolenate

PROPYLENE GLYCOL LINOLENATE

3.8

A gentle emollient that helps soften and smooth skin by replenishing essential fatty acids, with a low risk of irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Emollient

Propylene Glycol Oleate

Propylene Glycol Oleate

3.8

A mild emollient and emulsifier that helps soften skin and blend ingredients, but may be slightly pore-clogging for acne-prone skin.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Emulsifier

Propylene Glycol Oleate SE

Propylene Glycol Oleate SE

3.5

A reliable emulsifier that helps blend oil and water in creams, but it's not a star active ingredient for skin benefits.

Irritation

low

Source

semi-synthetic

beautyskincareemollientemulsifier
Read ingredient review

Emulsifier

Propylene Glycol Oleth-5

PROPYLENE GLYCOL OLETH-5

3.8

A synthetic emulsifier that helps mix oil and water in products, but may cause mild irritation for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincareemulsifier
Read ingredient review

Emollient

Propylene Glycol Ricinoleate

Propylene Glycol Ricinoleate

3.8

A gentle emollient that helps soften skin and improve product texture, with a low risk of irritation or clogged pores.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Emollient

Propylene Glycol Soyate

PROPYLENE GLYCOL SOYATE

3.8

A gentle, plant-based emollient that helps soften and smooth skin without heavy greasiness.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Emulsifier

Propylene Glycol Stearate

Propylene Glycol Stearate

3.8

A reliable emulsifier that helps create smooth, stable creams and lotions with a low risk of irritation.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
Read ingredient review

Emulsifier

Propylene Glycol Stearate SE

Propylene Glycol Stearate SE

4.0

A reliable emulsifier that helps water and oil mix into a stable, creamy texture without common irritation concerns.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
Read ingredient review

Emollient

Propylheptyl Caprylate

Propylheptyl Caprylate

4.0

A silky, lightweight emollient that helps products spread smoothly without feeling heavy or greasy.

Irritation

low

Source

synthetic

beautyskincareemollient
Read ingredient review

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
Read ingredient review

Preservative

Propylparaben

Propylparaben

3.5

Propylparaben is an effective preservative but has raised safety concerns due to potential endocrine-disrupting effects, leading many brands to phase it out.

Irritation

low

Source

synthetic

beautyskincarepreservative
Read ingredient review

Hair conditioning agent

Propyltrimonium Hydrolyzed Wheat Protein

PROPYLTRIMONIUM HYDROLYZED WHEAT PROTEIN

4.0

A gentle, positively charged wheat protein that coats hair to improve softness, manageability, and shine without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
Read ingredient review

Antioxidant

Prostanthera Incisa Leaf Extract

PROSTANTHERA INCISA LEAF EXTRACT

4.0

A gentle botanical extract with antioxidant and soothing potential, best for those seeking natural, plant-based skincare ingredients.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Film Former

Protamine Sulfate

PROTAMINE SULFATE

3.5

Protamine sulfate is a gentle film-forming protein that can help condition hair and skin, but its benefits are mild and not well-studied in cosmetics.

Irritation

low

Source

natural

beautyskincarefilm-former
Read ingredient review

Humectant

Protea Repens Flower Nectar

PROTEA REPENS FLOWER NECTAR

3.8

A gentle, natural humectant from South African protea flowers that helps hydrate skin, but research on its specific benefits is still limited.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Exfoliant

Protease

Protease

4.0

Protease is an enzyme exfoliant that gently dissolves dead skin cells, but it can be irritating if left on too long or used too frequently.

Irritation

moderate

Source

biotech

beautyskincareexfoliant
Read ingredient review

Antioxidant

Protium Pallidum Extract

PROTIUM PALLIDUM EXTRACT

3.8

A gentle, antioxidant-rich botanical extract that may help calm skin and fight free radical damage, though research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Protocatechualdehyde

Protocatechualdehyde

4.0

A gentle antioxidant that helps defend skin from environmental stress and may calm irritation.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Protocatechuic Acid

3,4-DIHYDROXYBENZOIC ACID

4.0

A gentle antioxidant that helps protect skin from environmental stress and may support a more even tone.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Protodioscin

PROTODIOSCIN

3.5

Protodioscin is a plant saponin with early evidence of antioxidant and anti-inflammatory benefits, but human skincare studies are limited.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Soothing Agent

Prunasin

Prunasin

3.0

Prunasin is a plant-derived compound with early research suggesting soothing benefits, but it's not widely studied in cosmetics and requires careful sourcing.

Irritation

low

Source

natural

beautyskincaresoothing agent
Read ingredient review

Antioxidant

Prunella Vulgaris Extract

PRUNELLA VULGARIS FLOWER/LEAF/STEM EXTRACT

4.0

A gentle botanical extract that may help calm irritation and defend against environmental stress, though more human studies are needed.

Irritation

low

Source

natural

beautyskincarebotanical
Read ingredient review

Antioxidant

Prunus Davidiana Flower Extract

PRUNUS DAVIDIANA FLOWER EXTRACT

3.8

A gentle, antioxidant-rich flower extract that may help calm skin and fight free radicals, though research is still emerging.

Irritation

low

Source

natural

beautyskincarebotanical
Read ingredient review

Emollient

Prunus Insititia Seed Oil

PRUNUS INSITITIA SEED OIL

4.2

A gentle, non-greasy plant oil that hydrates and softens skin without clogging pores, making it a good choice for sensitive or acne-prone types.

Irritation

low

Source

natural

beautyskincareemollient
Read ingredient review

Antioxidant

Prunus Lannesiana Flower Extract

Prunus Lannesiana Flower Extract

3.8

A gentle, antioxidant-rich flower extract that may help calm skin and protect against environmental stress, though research is still emerging.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Prunus Mume Bud Extract

Prunus Mume Bud Extract

4.0

A gentle, antioxidant-rich botanical extract from Japanese apricot buds that may help soothe and protect skin from environmental stress.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Soothing Agent

Prunus Mume Flower Water

Prunus Mume Flower Water

3.8

A gentle floral water that may offer soothing and antioxidant benefits, but research is limited compared to more established ingredients.

Irritation

low

Source

natural

beautyskincaresoothing
Read ingredient review

Exfoliant

Prunus Mume Fruit Vinegar

PRUNUS MUME FRUIT VINEGAR

4.0

A gentle, naturally fermented fruit vinegar that exfoliates and brightens skin without the harshness of stronger acids.

Irritation

low

Source

natural

beautyskincareexfoliant
Read ingredient review

Antioxidant

Prunus Mume Root Extract

Prunus Mume Root Extract

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Exfoliant

Prunus Mume Seed Powder

PRUNUS MUME SEED POWDER

4.0

A natural, finely-milled seed powder that gently exfoliates without harsh microbeads, making it a eco-friendly choice for smooth skin.

Irritation

low

Source

natural

beautyskincareexfoliant
Read ingredient review

Emollient

Prunus Pedunculata Seed Oil

Prunus Pedunculata Seed Oil

4.0

A gentle, plant-based oil that hydrates and softens skin without clogging pores, though research on its specific benefits is still limited.

Irritation

low

Source

natural

beautyskincareemollient
Read ingredient review

Antioxidant

Prunus Speciosa Bark Extract

PRUNUS SPECIOSA BARK EXTRACT

3.8

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Prunus Speciosa Flower Extract

PRUNUS SPECIOSA FLOWER EXTRACT

3.8

A gentle flower extract with antioxidant potential, but research is limited and benefits are not yet proven in human studies.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Antioxidant

Prunus Speciosa Leaf Extract

Prunus Speciosa Leaf Extract

4.0

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Skin Conditioning

Prunus Speciosa Leaf Water

PRUNUS SPECIOSA LEAF WATER

3.8

A mild, antioxidant-rich botanical water that hydrates and soothes, but with limited scientific research backing its specific benefits.

Irritation

low

Source

natural

beautyskincarebotanical
Read ingredient review

Humectant

Prunus Triloba Fruit Water

PRUNUS TRILOBA FRUIT WATER

3.8

A gentle, water-like ingredient from flowering plum fruit that adds light hydration and a touch of antioxidants, but lacks strong clinical backing.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Antioxidant

Prunus Zippeliana Extract

PRUNUS ZIPPELIANA BARK/TWIG EXTRACT

3.8

A gentle plant extract with antioxidant potential, but research on its specific benefits for skin is still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Soothing Agent

Pseudoalteromonas Ferment Extract

Pseudoalteromonas Ferment Lysate Extract Filtrate

4.3

A gentle marine probiotic ingredient that calms irritation and strengthens the skin barrier, ideal for sensitive or reactive skin.

Irritation

low

Source

biotech

beautyskincaresoothing agent
Read ingredient review

Soothing agent

Pseudomonas Ferment Extract

PSEUDOMONAS AEROGINOSA CULTURE CONDITIONED MEDIA EXTRACT

3.5

A bacterial ferment extract that may help calm skin and support the barrier, but research is still early and the ingredient name can sound alarming.

Irritation

low

Source

biotech

beautyskincaresoothing agent
Read ingredient review

Skin conditioning

Psiadia Altissima Leaf Oil

Psiadia altissima leaf oil

3.8

A gentle botanical oil with early evidence of antioxidant activity, but more research is needed to confirm its benefits for skin.

Irritation

low

Source

natural

beautyskincarebotanical oil
Read ingredient review

Humectant

Psicose

PSICOSE

4.0

Psicose is a gentle, natural humectant that helps hydrate skin and may offer antioxidant benefits, though research in cosmetics is still limited.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Thickener

Psyllium Husk Powder

PLANTAGO PSYLLIUM HUSK POWDER

3.8

A gentle, plant-based thickener that creates a soothing gel texture, but it can feel sticky if used too high.

Irritation

low

Source

natural

beautyskincarethickener
Read ingredient review

Antioxidant

Pteris Dispar Leaf Extract

PTERIS DISPAR LEAF EXTRACT

3.5

A fern-derived extract with antioxidant potential, but research is limited and benefits are not yet well-established in human skin.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review