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

Antioxidant

Acetyl Histidine

Acetyl Histidine

3.8

A gentle antioxidant that may help protect skin from environmental stress, but research is still early.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
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Skin-lightening agent

Acetyl Hydroquinone

2-ACETYLHYDROQUINONE

3.0

A synthetic derivative of hydroquinone that may lighten dark spots, but its safety and efficacy are less established than the parent compound.

Irritation

moderate

Source

synthetic

beautyskincareskin-lightening agent
Read ingredient review

Fragrance Ingredient

Acetyl Isopropyl Tetramethyl Indane

ACETYLISOPROPYLTETRAMETHYLINDANE

3.5

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

Irritation

low

Source

synthetic

beautyskincarefragrance
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Antioxidant

Acetyl Methionine

Acetyl Methionine

4.0

Acetyl Methionine is a gentle, antioxidant amino acid derivative that helps protect skin from environmental stress and supports a healthy appearance.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
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Soothing agent

Acetyl Methyl Oleanolate

Acetyl Methyl Oleanolate

4.0

A gentle, plant-derived compound that helps calm redness and supports the skin's natural repair process.

Irritation

low

Source

semi-synthetic

beautyskincaresoothing agent
Read ingredient review

Anti-aging agent

Acetyl Monofluoroheptapeptide-1

Acetyl Monofluoroheptapeptide-1

3.8

A cutting-edge synthetic peptide that may help firm skin, but research is still limited compared to more established peptides.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-wrinkle agent

Acetyl Octapeptide-17 Amide

Acetyl Octapeptide-17 Amide

4.0

A synthetic peptide that may soften expression lines by mimicking the action of a muscle-relaxing protein, but results are subtle and temporary.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Octapeptide-2

ACETYL OCTAPEPTIDE-2

3.8

A synthetic peptide that may help soften fine lines by signaling skin to support collagen, but results are subtle and require consistent use.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-wrinkle agent

Acetyl Octapeptide-29 Amide

Acetyl Octapeptide-29 Amide

4.0

A synthetic peptide that mimics the action of botulinum toxin to soften expression lines, but with milder, temporary effects.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-wrinkle agent

Acetyl Octapeptide-3

Acetyl Octapeptide-3

4.0

A synthetic peptide that mimics the action of botulinum toxin to soften expression wrinkles, but with milder and temporary effects.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-aging agent

Acetyl Oligopeptide-129

Acetyl Oligopeptide-129 Amidopropoxy PEG-2 Propylamine

3.8

A synthetic peptide that may help support skin firmness and reduce fine lines, but research is still emerging.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-aging agent

Acetyl Oligopeptide-70

Acetyl Oligopeptide-70

4.0

A synthetic peptide that may help soften the look of expression lines with consistent use, but results are subtle and not instant.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Humectant

Acetyl Ornithine

Acetyl Ornithine

3.8

A gentle amino acid derivative that helps maintain skin hydration and supports a healthy barrier, but research is still early.

Irritation

low

Source

semi-synthetic

beautyskincarehumectant
Read ingredient review

Anti-aging agent

Acetyl Pentapeptide-35

Acetyl Pentapeptide-35

4.0

A synthetic peptide that may help improve skin firmness and soften the look of wrinkles with low irritation risk.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Humectant

Acetyl Proline

Acetyl Proline

4.0

A gentle amino acid derivative that helps maintain skin moisture and supports a smoother appearance.

Irritation

low

Source

semi-synthetic

beautyskincarehumectant
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Antioxidant

Acetyl Rhubarb Root Extract

Acetyl Rheum Rhaponticum Root Extract

4.0

A gentle, antioxidant-rich extract that may help calm skin and fight environmental stress, but research is still early.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
Read ingredient review

Anti-Wrinkle Agent

Acetyl S-FEA's Viper Pentapeptide-1 Amide

Acetyl S-FEA's Viper Pentapeptide-1 Amide

3.8

A synthetic peptide that mimics snake venom to temporarily relax expression wrinkles, offering a gentle alternative to neurotoxins like Botox.

Irritation

low

Source

synthetic

beautyskincarepeptide
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Anti-aging agent

Acetyl SH-Heptapeptide-1

Acetyl SH-Heptapeptide-1

4.0

A synthetic peptide that may help soften fine lines and support firmer-looking skin, but more independent human studies are needed.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-wrinkle agent

Acetyl SH-Nonapeptide-5

Acetyl SH-Nonapeptide-5

3.8

A synthetic peptide that mimics the effects of neuromodulators to soften expression lines, but results are subtle and temporary.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-aging

Acetyl SH-Pentapeptide-1

Acetyl SH-Pentapeptide-1

4.0

A synthetic peptide that may help support collagen and improve skin firmness with low irritation risk.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl SH-Pentapeptide-35

Acetyl SH-Pentapeptide-35

4.0

A lab-made peptide that may help soften expression lines and improve skin firmness, but human studies are still limited.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-aging

Acetyl SH-Tetrapeptide-1

ACETYL SH-TETRAPEPTIDE-1

4.0

A gentle peptide that may help support skin firmness and reduce fine lines, but more human studies are needed to confirm its effects.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Skin conditioning agent

Acetyl Tetrapeptide-11

Acetyl Tetrapeptide-11

4.0

A synthetic peptide that signals skin cells to support collagen and elastin, helping improve firmness and reduce fine lines.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging

Acetyl Tetrapeptide-15

Acetyl Tetrapeptide-15

4.0

A synthetic peptide that may help improve skin firmness and reduce fine lines, with low irritation potential.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging

Acetyl Tetrapeptide-17

Acetyl Tetrapeptide-17

3.8

A synthetic peptide that may help improve skin firmness and reduce fine lines, but research is still emerging.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Soothing agent

Acetyl Tetrapeptide-18

Acetyl Tetrapeptide-18

4.0

A gentle peptide that helps calm reactive skin and reduce visible redness, making it a smart choice for sensitive skin routines.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Skin conditioning agent

Acetyl Tetrapeptide-2

Acetyl Tetrapeptide-2

4.0

A gentle peptide that may help firm skin and reduce under-eye bags, but results are subtle and require consistent use.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Soothing agent

Acetyl Tetrapeptide-22

Acetyl Tetrapeptide-22

4.0

A gentle peptide that may help reduce visible redness and sensitivity over time, but results are subtle and not instant.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-Aging Agent

Acetyl Tetrapeptide-27

Acetyl Tetrapeptide-27

4.0

A synthetic peptide that may help improve skin firmness and reduce fine lines, but research is still emerging.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Firming agent

Acetyl Tetrapeptide-3

Acetyl Tetrapeptide-3

4.0

A synthetic peptide that targets under-eye concerns like puffiness and dark circles by supporting collagen and circulation.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Firming agent

Acetyl Tetrapeptide-40

Acetyl Tetrapeptide-40

4.0

A gentle synthetic peptide that may help firm skin and reduce under-eye puffiness, with limited but promising early research.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Soothing agent

Acetyl Tetrapeptide-5

Acetyl Tetrapeptide-5

4.0

A gentle peptide that targets under-eye bags and dark circles by supporting circulation and reducing fluid buildup.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging

Acetyl Tetrapeptide-9

Acetyl Tetrapeptide-9

4.0

A lab-made peptide that encourages collagen production for firmer, smoother skin with a very low risk of irritation.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-wrinkle agent

Acetyl Trifluoromethylphenyl Valylglycine

Acetyl Trifluoromethylphenyl Valylglycine

3.8

A synthetic peptide that may help soften expression lines by temporarily relaxing facial muscles, but results are subtle and not as strong as injectable treatments.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Emollient

Acetyl Trihexyl Citrate

Acetyl Trihexyl Citrate

4.2

A gentle, low-irritation emollient that helps products spread smoothly and keeps nail polish flexible.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Anti-wrinkle agent

Acetyl Tripeptide-30 Citrulline

Acetyl Tripeptide-30 Citrulline

4.0

A synthetic peptide that may help soften expression lines by temporarily relaxing facial muscles, similar to a milder, topical alternative to injectables.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Tripeptide-59 Amide

Acetyl Tripeptide-59 Amide

4.0

A synthetic peptide that may help firm skin and soften lines, but long-term human data is still limited.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Brightening Agent

Acetyl Tyrosinamide

Acetyl Tyrosinamide

3.8

A gentle amino acid derivative that may help brighten skin and reduce dark spots with minimal irritation.

Irritation

low

Source

semi-synthetic

beautyskincarebrightening agent
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Antioxidant

Acetyl Tyrosine

Acetyl Tyrosine

4.0

Acetyl Tyrosine is a gentle amino acid derivative that helps maintain an even skin tone and supports the skin's natural antioxidant defenses.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
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Antioxidant

Acetyl Zingerone

Acetyl Zingerone

4.3

A gentle, ginger-derived antioxidant that helps defend against pollution and UV stress without the irritation of pure ginger.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
Read ingredient review

Anti-wrinkle agent

Acetylarginyltryptophyl Diphenylglycine

Acetylarginyltryptophyl Diphenylglycine

4.0

A synthetic peptide that may help soften expression lines by temporarily relaxing facial muscles, similar to a milder version of neuropeptides.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Fragrance Ingredient

Acetylated Amyris Oil

AMYRIS BALSAMIFERA OIL ACETYLATED

3.8

A gentle, semi-synthetic emollient and fragrance ingredient derived from amyris oil, offering a subtle woody scent with good skin tolerance.

Irritation

low

Source

semi-synthetic

beautyskincarefragrance
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Skin conditioning agent

Acetylated Cetyl Hydroxyprolinate

Acetylated Cetyl Hydroxyprolinate

4.0

A gentle, amino-acid-based ingredient that helps hydrate and plump the skin by supporting its natural moisture network.

Irritation

low

Source

semi-synthetic

beautyskincareconditioning agent
Read ingredient review

Antioxidant

Acetylated Clove Extract

EUGENIA CARYOPHYLLUS EXTRACT ACETYLATED

3.8

A modified clove extract that may offer antioxidant benefits, but its acetylation process and potential for irritation require cautious use.

Irritation

moderate

Source

semi-synthetic

beautyskincareantioxidant
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Emollient

Acetylated Copaiba Balsam Oil

COPAIFERA RETICULATA BALSAM OIL ACETYLATED

3.8

A gentle, modified plant oil that helps soften skin and improve product texture, but research on its specific benefits is still limited.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
Read ingredient review

Antioxidant

Acetylated Cypress Wood Extract

CUPRESSUS FUNEBRIS WOOD EXTRACT ACETYLATED

3.8

A gentle, modified wood extract that may help protect skin from environmental stress, but research on its specific benefits is still limited.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
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Emollient

Acetylated Glycol Stearate

Acetylated Glycol Stearate

3.8

A gentle synthetic emollient that softens skin and improves product feel, with a low risk of irritation or clogged pores.

Irritation

low

Source

synthetic

beautyskincareemollient
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