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

Film Former

Gelatin Lysine Polyacrylamide Complex

GELATIN/LYSINE/POLYACRYLAMIDE HYDROXYPROPYLTRIMONIUM CHLORIDE

3.8

A conditioning polymer blend that helps hair and skin feel smooth and soft, but its synthetic nature and limited research may give some users pause.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Antistatic Agent

Ginseng Hydroxypropyltrimonium Chloride

Ginseng Hydroxypropyltrimonium Chloride

4.0

A gentle conditioning ingredient that helps reduce static and improve softness in hair and skin products, with added antioxidant benefits from ginseng.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Film Former

Gluconamido Amodimethicone

Gluconamido Amodimethicone

4.0

A gentle, modified silicone that smooths hair and skin without heavy buildup, making it a good choice for fine or oily hair types.

Irritation

low

Source

synthetic

beautyskincarehaircareconditioning agent
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Skin conditioning agent

Glutamylamidoethyl Indole

Glutamylamidoethyl Indole

3.5

A novel synthetic ingredient with limited but promising research for skin conditioning and protection.

Irritation

low

Source

synthetic

beautyskincareconditioning agent
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Humectant

Glycoproteins

GLYCOPROTEINS

4.0

Glycoproteins are gentle, naturally derived molecules that help hydrate and support skin structure, but they are not a replacement for proven anti-aging ingredients like retinoids or peptides.

Irritation

low

Source

natural

beautyskincarehumectantconditioning agent
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Hair conditioning agent

Glyoxyloyl Keratin Amino Acids

GLYOXYLOYL KERATIN AMINO ACIDS

4.0

A gentle keratin-derived ingredient that helps smooth and strengthen hair without harsh chemicals, ideal for those seeking a milder alternative to traditional straightening treatments.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Surfactant

Guanidine Surfactant Blend

Laur/myrist/palmitamidobutyl guanidine acetate

3.5

A gentle synthetic conditioning agent that helps detangle and soften hair without heavy buildup.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Antistatic Agent

Guar Hydroxypropyltrimonium Chloride

GUAR HYDROXYPROPYLTRIMONIUM CHLORIDE

4.0

A gentle, plant-derived conditioning ingredient that makes hair softer and less frizzy without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Skin conditioning agent

Hexyldecyl Hydrolyzed Collagen

HEXYLDECYL ESTER OF HYDROLYZED COLLAGEN

3.8

A modified collagen that helps skin feel smooth and hydrated, but its anti-aging effects are mostly surface-level.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Conditioning Agent

Hydrogenated Tallowalkonium Chloride

Hydrogenated Tallowalkonium Chloride

3.5

A conditioning ingredient derived from animal fats that softens hair and reduces static, but may cause irritation or clog pores in sensitive individuals.

Irritation

moderate

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Skin conditioning agent

Hydrolyzed Antler Velvet

Hydrolyzed Antler Velvet

3.5

Hydrolyzed Antler Velvet is a novel protein ingredient that may help hydrate and condition skin, but scientific evidence for anti-aging benefits is very limited.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Hair Conditioning Agent

Hydrolyzed Brazil Nut Protein

Hydrolyzed Brazil Nut Protein

4.0

A gentle, plant-based protein that can temporarily strengthen hair and lightly moisturize skin without irritation.

Irritation

low

Source

natural

beautyskincarehaircareconditioning agent
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Skin conditioning

Hydrolyzed Calf Tissue Complex

HYDROLYZED CALF LIGAMENTS/LIVER/SKIN

2.5

An animal-derived protein ingredient that may temporarily smooth skin, but lacks strong evidence and raises ethical and sourcing concerns.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Hair Conditioning Agent

Hydrolyzed Corn Soy Wheat Protein Complex

HYDROLYZED CORN/SOY/WHEAT PROTEIN THIOGLYCOLAMIDE/THIOPROPIONAMIDE

3.8

A modified plant protein that bonds to hair to strengthen and repair damage, but its synthetic modification may not suit all preferences.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Skin conditioning agent

Hydrolyzed Goat Milk Extract

Hydrolyzed Goat Milk Extract

4.0

A nourishing, protein-packed ingredient that hydrates and soothes without clogging pores.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Skin Conditioning Agent

Hydrolyzed Horse Placenta/Umbilical Extract

HYDROLYZED HORSE PLACENTA/UMBILICAL EXTRACT

3.5

A protein-rich animal-derived extract that may help hydrate and condition skin, but lacks strong independent research and raises ethical considerations.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Skin Conditioning

Hydrolyzed Maca Root

Hydrolyzed Lepidium Meyenii Root

4.0

A gentle, antioxidant-rich ingredient that helps condition and protect the skin without irritation.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Hair Conditioning Agent

Hydrolyzed Oat Protein (Quaternized)

HYDROXYPROPYLTRIMONIUM HYDROLYZED OAT PROTEIN

4.3

A gentle, positively charged oat protein that clings to hair and skin to reduce frizz, add softness, and improve moisture retention without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Humectant

Hydrolyzed Quinoa

Hydrolyzed Quinoa

4.0

Hydrolyzed Quinoa is a gentle, plant-based protein that helps hydrate and reinforce the skin barrier without clogging pores.

Irritation

low

Source

natural

beautyskincarehumectantconditioning agent
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Skin conditioning

Hydrolyzed Rapeseed Extract

Hydrolyzed Brassica Napus Seedcake Extract

4.0

A gentle, plant-based skin conditioner that may help soothe and soften skin with minimal irritation risk.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Skin conditioning agent

Hydrolyzed Royal Jelly Protein

Hydrolyzed Royal Jelly Protein

3.8

A gentle, protein-rich ingredient that helps hydrate and condition skin, but its anti-aging benefits are not as dramatic as marketing suggests.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Skin conditioning

Hydrolyzed Sea Hare Extract

HYDROLYZED KURODA'S SEA HARE EXTRACT

3.5

An exotic marine extract with potential skin conditioning benefits, but very limited research and a high novelty factor.

Irritation

low

Source

natural

beautyskincareconditioning agent
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Hair Conditioning Agent

Hydrolyzed Sesame Protein

Hydrolyzed Sesame Protein

4.0

A gentle, plant-based protein that strengthens hair and lightly hydrates skin without common irritation or clogging.

Irritation

low

Source

natural

beautyskincarehaircareconditioning agent
Read ingredient review

Humectant

Hydrolyzed Shea Seedcake Extract

Hydrolyzed Shea Seedcake Extract

4.0

A gentle, protein-rich extract from shea butter production that helps hydrate and condition skin without clogging pores.

Irritation

low

Source

natural

beautyskincarehumectantconditioning agent
Read ingredient review

Film Former

Hydrolyzed Wheat Protein Complex

WHEATGERMAMIDOPROPYL DIMETHYLAMINE HYDROLYZED WHEAT PROTEIN

4.0

A gentle, protein-based conditioner that helps strengthen hair and leaves skin feeling smooth without heavy residue.

Irritation

low

Source

natural

beautyskincarehaircareconditioning agent
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Hair Conditioning Agent

Hydrolyzed Wheat Protein Siloxysilicate

HYDROXYPROPYLTRIMONIUM HYDROLYZED WHEAT PROTEIN/SILOXYSILICATE

4.0

A gentle conditioning ingredient that smooths hair and skin without heavy buildup, but may not suit those avoiding silicones or wheat-derived ingredients.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Antistatic agent

Hydroxyethyl Acetomonium PG-Dimethicone

HYDROXYETHYL ACETOMONIUM PG-DIMETHICONE

4.0

A gentle silicone derivative that smooths hair and skin without heavy buildup, but may not suit those avoiding all silicones.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
Read ingredient review

Antistatic Agent

Hydroxyethyl Cetyldimonium Chloride

HYDROXYETHYL CETYLDIMONIUM CHLORIDE

3.8

A synthetic conditioning ingredient that reduces frizz and improves manageability, but may cause buildup with frequent use.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
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Conditioning Agent

Hydroxyethyl Tallowdimonium Chloride

Hydroxyethyl Tallowdimonium Chloride

3.5

An effective hair and skin conditioner derived from tallow, but may cause irritation or clog pores in sensitive or acne-prone individuals.

Irritation

moderate

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Skin conditioning agent

Hydroxyproline Palmitamide

Hydroxyproline Palmitamide

4.0

A gentle peptide-like ingredient that may help improve skin firmness and hydration with low irritation risk.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
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Antistatic Agent

Hydroxypropyl Bistrimonium Diiodide

Hydroxypropyl Bistrimonium Diiodide

3.5

A synthetic conditioning agent that helps reduce static and improve manageability, but its iodine content raises mild safety questions for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincareconditioning agent
Read ingredient review

Hair conditioning agent

Hydroxypropyltrimonium Hydrolyzed Casein

HYDROXYPROPYLTRIMONIUM HYDROLYZED CASEIN

4.0

A gentle, protein-based conditioning ingredient that helps strengthen hair and improve manageability with low irritation risk.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
Read ingredient review

Hair Conditioning Agent

Hydroxypropyltrimonium Hydrolyzed Keratin

Hydroxypropyltrimonium Hydrolyzed Keratin

4.0

A gentle, positively charged keratin derivative that bonds to damaged hair to improve strength, smoothness, and manageability without buildup.

Irritation

low

Source

semi-synthetic

beautyhaircareconditioning agent
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Hair Conditioning Agent

Hydroxypropyltrimonium Hydrolyzed Whey

Hydroxypropyltrimonium Hydrolyzed Whey

4.0

A gentle, protein-derived conditioning ingredient that adds softness and manageability to hair without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair Conditioner

Hydroxypropyltrimonium Inulin

Hydroxypropyltrimonium Inulin

4.3

A gentle, plant-based conditioning ingredient that makes hair softer and less frizzy without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair conditioning agent

Hydroxypropyltrimonium Lemon Protein

HYDROXYPROPYLTRIMONIUM LEMON PROTEIN

3.8

A gentle, plant-derived conditioning ingredient that helps detangle hair and soften skin without heavy buildup.

Irritation

low

Source

semi-synthetic

beautyskincarehaircareconditioning agent
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Hair conditioning agent

Imidazolylethyl Diaminopropanamide HCl

IMIDAZOLYLETHYL DIAMINOPROPANAMIDE HCL

3.8

A synthetic hair-strengthening ingredient that helps repair damage and improve hair resilience, but research is limited to manufacturer studies.

Irritation

low

Source

synthetic

beautyhaircareconditioning agent
Read ingredient review