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 569
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

Skin conditioning agent

Inosine

Inosine

3.8

Inosine is a gentle skin-conditioning ingredient that may support firmness and texture, but research on its cosmetic benefits is still emerging.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Film Former

Iodized Corn Protein

IODIZED CORN PROTEIN

3.5

A gentle film-forming protein that can add light conditioning and a smooth feel, but research on its iodized version is limited.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Skin conditioning agent

Isopentyl Caprylamide

Isopentyl Caprylamide

3.5

A gentle synthetic ingredient that helps improve the feel and conditioning of skincare and hair products, with a low risk of irritation.

Irritation

low

Source

synthetic

beautyskincareconditioning agent
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Antistatic Agent

Isostearamidopropyl PG-Dimonium Chloride

Isostearamidopropyl PG-Dimonium Chloride

3.8

A gentle conditioning ingredient that helps hair feel soft and smooth without heavy buildup, but may not suit very fine or oily hair types.

Irritation

low

Source

synthetic

beautyskincarehaircareconditioning agent
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Skin conditioner

Isostearoyl Hydrolyzed Collagen

ISOSTEAROYL HYDROLYZED COLLAGEN

4.0

A gentle conditioning ingredient that helps skin and hair feel smooth and soft without being heavy.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair conditioning agent

Isostearoyl Hydrolyzed Keratin

Isostearoyl Hydrolyzed Keratin

4.0

A gentle, modified keratin that helps strengthen hair and reduce frizz without the harshness of some other protein treatments.

Irritation

low

Source

semi-synthetic

beautyhair careconditioning agent
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Antistatic Agent

Isostearyl Benzimidonium Chloride

Isostearyl Benzimidonium Chloride

3.5

A synthetic conditioning ingredient that helps reduce static and improve hair manageability, but is less common in modern formulations.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Antistatic Agent

Isostearyl Ethyldimonium Chloride

Isostearyl Ethyldimonium Chloride

3.8

A gentle synthetic conditioner that reduces static and smooths hair without heavy buildup, suitable for most hair types.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Antistatic Agent

Isostearyl Ethylimidazolinium Ethosulfate

Isostearyl Ethylimidazolinium Ethosulfate

3.5

A synthetic antistatic ingredient that helps reduce frizz and flyaways in hair products, but it offers no long-term repair or moisturizing benefits.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Hair Conditioning Agent

Keratin Amino Acid Complex

GELATIN/KERATIN AMINO ACIDS/LYSINE HYDROXYPROPYLTRIMONIUM CHLORIDE

4.0

A protein-rich conditioning complex that helps strengthen hair and reduce frizz, but may not suit very fine or low-porosity hair.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Hair conditioning agent

Keratin Succinate Complex

CETEARAMIDOETHYLDIETHONIUM SUCCINOYL HYDROLYZED KERATIN

4.0

A modified keratin that helps repair and strengthen hair, but may not suit very fine or low-porosity hair if overused.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Exfoliant

Lactis Faex

Lactis Faex

4.0

A gentle, naturally derived exfoliant and skin conditioner from fermented milk, suitable for most skin types.

Irritation

low

Source

natural

beautyskincareexfoliantconditioning agent
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Skin conditioning agent

Lactobacillus/Horse Fat Ferment Filtrate

LACTOBACILLUS/HORSE FAT FERMENT FILTRATE

3.5

A novel fermented ingredient that may help moisturize and condition skin, but research is limited and it may be comedogenic for some.

Irritation

low

Source

biotech

beautyskincareconditioning agent
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Skin conditioner

Lactobacillus/Milk/Soybean Oil Ferment

LACTOBACILLUS/MILK/GLYCINE SOJA OIL FERMENT

4.0

A fermented blend that combines the nourishing benefits of milk and soybean oil with probiotic byproducts, offering gentle skin conditioning and moisture support.

Irritation

low

Source

biotech

beautyskincareconditioning agent
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Skin conditioning

Lake Whitefish Extract

COREGONUS CLUPEAFORMIS EXTRACT

3.5

A novel marine-derived extract that may help hydrate and condition skin, but research is limited and it's not a proven powerhouse.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Hair Conditioning Agent

Lauramidobutyl Guanidine Acetate

Lauramidobutyl Guanidine Acetate

3.8

A synthetic hair conditioning agent that helps soften and detangle hair, but is not widely studied for long-term effects.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Hair Conditioning Agent

Lauramidobutyl Guanidine HCl

Lauramidobutyl Guanidine HCl

3.8

A synthetic hair conditioning agent that helps detangle and soften hair without heavy buildup, but has limited research on long-term effects.

Irritation

low

Source

synthetic

beautyskincarehair careconditioning agent
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Conditioning Agent

Laurdimonium Hydroxypropyl Amino Acid Complex

LAURDIMONIUM HYDROXYPROPYL (ARGININE/GLUTAMIC ACID/ISOLEUCINE/LEUCINE/LYSINE/PHENYLALANINE/PROLINE/THREONINE/VALINE)

4.0

A gentle conditioning ingredient that helps detangle hair and soften skin without heavy buildup, suitable for sensitive types.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair Conditioning Agent

Laurdimonium Hydroxypropyl Hydrolyzed Casein

LAURDIMONIUM HYDROXYPROPYL HYDROLYZED CASEIN

4.0

A gentle, protein-based conditioning ingredient that helps smooth hair and lightly moisturize skin without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Skin conditioning agent

Laurimino Bispropanediol

Laurimino Bispropanediol

3.8

A gentle synthetic conditioning agent that helps products feel smoother and less drying, but it's not a standout active ingredient.

Irritation

low

Source

synthetic

beautyskincareconditioning agent
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Film Former

Lauroyl Hydrolyzed Elastin

Lauroyl Hydrolyzed Elastin

3.8

A gentle, modified protein that adds a temporary smoothing and conditioning feel to skin and hair, but does not restore lost elastin.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Antistatic Agent

Lauroyl PG-Trimonium Chloride

Lauroyl PG-Trimonium Chloride

4.0

A gentle conditioning ingredient that reduces static and improves softness without heavy buildup.

Irritation

low

Source

synthetic

beautyskincarehaircareconditioning agent
Read ingredient review

Skin Conditioning Agent

Lauryl Pyrrolidone

Lauryl Pyrrolidone

3.8

Lauryl Pyrrolidone is a synthetic ingredient that helps other actives absorb better while smoothing the skin, but its penetration-enhancing effect means it should be used with care in formulations.

Irritation

low

Source

synthetic

beautyskincareconditioning agent
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Conditioning Agent

Linoleamidopropyl Dimethylamine

LINOLEAMIDOPROPYL DIMETHYLAMINE

3.8

A gentle conditioning ingredient that helps detangle hair and soften skin without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Skin conditioning agent

Lysine Carboxymethyl Cysteinate

LYSINE CARBOXYMETHYL CYSTEINATE

3.8

A gentle amino acid derivative that may help strengthen the skin barrier and provide antioxidant support, though research is still limited.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Antistatic Agent

Methoxycinnamidopropyl Behendimonium Chloride

Methoxycinnamidopropyl Behendimonium Chloride

3.5

A synthetic conditioning ingredient that helps reduce static and improve hair manageability, but its long-chain structure may cause buildup on fine or low-porosity hair.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Hair Conditioning Agent

Methoxycinnamidopropyl Laurdimonium Tosylate

Methoxycinnamidopropyl Laurdimonium Tosylate

3.8

A synthetic conditioning ingredient that helps detangle hair and may offer mild UV protection, but its benefits are modest compared to dedicated UV filters.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Conditioning Agent

Methyl Hydroxycetyl Glucaminium Lactate

Methyl Hydroxycetyl Glucaminium Lactate

4.0

A mild, sugar-derived conditioning agent that softens skin and adds a gentle antimicrobial boost, ideal for sensitive skin cleansers.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Antistatic Agent

Methylenebis Tallow Acetamidodimonium Chloride

Methylenebis Tallow Acetamidodimonium Chloride

3.5

A classic conditioning ingredient that smooths hair and reduces static, but its animal-derived source and limited eco-profile may not suit everyone.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Skin conditioning

Methylmethionine

METHYLMETHIONINE

3.8

Methylmethionine is a gentle, soothing amino acid derivative that may help calm irritation and support skin barrier function, though research is still emerging.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Skin conditioning

Methylsilanol Acetylmethionate

METHYLSILANOL ACETYLMETHIONATE

3.8

A silicon-amino acid hybrid that may help smooth and condition skin, but research is limited.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Skin conditioning agent

Methylsilanol Acetyltyrosine

Methylsilanol Acetyltyrosine

4.0

A silicon-enhanced amino acid that supports skin firmness and resilience, best for aging or stressed skin.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Skin conditioning agent

Methylsilanol Spirulinate

Methylsilanol Spirulinate

4.0

A hybrid ingredient that combines the antioxidant power of spirulina with the film-forming, skin-smoothing benefits of silicon, making it a gentle option for firming and anti-aging products.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Skin conditioning agent

Mineral Ferment Complex

SACCHAROMYCES/ZINC/IRON/GERMANIUM/COPPER/MAGNESIUM/SILICON FERMENT

4.0

A gentle, biotech-derived blend of yeast ferment and trace minerals that may support skin barrier function and radiance.

Irritation

low

Source

biotech

beautyskincareconditioning agent
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Skin conditioning agent

Monascus Rice Ferment Filtrate

Monascus/Rice Ferment Filtrate

4.0

A fermented rice filtrate that may help brighten and condition skin, but research is still emerging.

Irritation

low

Source

biotech

beautyskincareconditioning agent
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Antioxidant

Moringa Ferment Filtrate

Saccharomyces/Moringa Oleifera Seed Oil/Glycerin Ferment Filtrate

4.0

A gentle, antioxidant-rich ferment that helps soothe and condition skin while supporting a healthy-looking complexion.

Irritation

low

Source

biotech

beautyskincareantioxidantconditioning agent
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Conditioning Agent

Myristamidopropyl Dimethylamine

MYRISTAMIDOPROPYL DIMETHYLAMINE

4.0

A gentle conditioning ingredient that helps hair feel soft and skin feel smooth without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
Read ingredient review