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

Antioxidant

Acetyl Carnitine HCl

ACETYL CARNITINE HCL

3.8

Acetyl Carnitine HCl is a gentle antioxidant that may help protect skin from environmental stress and support a more even tone, though it is not as well-studied as vitamin C or niacinamide.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
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Antioxidant

Acetyl Carnosine

Acetyl Carnosine

4.0

A stable antioxidant peptide that helps protect skin from environmental damage and may support a more youthful appearance.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
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Skin conditioning agent

Acetyl Citrull Amido Arginine

Acetyl Citrull Amido Arginine

4.0

A gentle amino-acid derivative that may help support skin firmness and resilience, though research is still emerging.

Irritation

low

Source

semi-synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Cyclohexapeptide-34

Acetyl Cyclohexapeptide-34

4.0

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

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Antioxidant

Acetyl Cysteine

ACETYL CYSTEINE

3.8

Acetyl Cysteine is a promising antioxidant and brightening ingredient, but research in topical skincare is still emerging compared to more established options like vitamin C.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
Read ingredient review

Skin conditioning agent

Acetyl Decapeptide-3

Acetyl Decapeptide-3

4.0

A synthetic peptide that may help reduce the appearance of fine lines and improve skin firmness with consistent use.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-aging agent

Acetyl Dipeptide-3 Aminohexanoate

Acetyl Dipeptide-3 Aminohexanoate

3.8

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

beautyskincareanti-aging
Read ingredient review

Anti-aging agent

Acetyl Dipeptide-31 Amide

ACETYL DIPEPTIDE-31 AMIDE

4.0

A synthetic peptide that may help soften expression lines and improve skin firmness with minimal irritation risk.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Moisturizer

Acetyl Dipeptide-32 Amide

Acetyl Dipeptide-32 Amide

4.0

A gentle peptide that helps strengthen the skin barrier and soften the look of expression lines over time.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Skin conditioning agent

Acetyl Farnesylcysteine

Acetyl Farnesylcysteine

3.5

A synthetic peptide-like ingredient that may help support skin firmness, but research is still early and benefits are not yet proven in large human studies.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Humectant

Acetyl Galactosamine

Acetyl Galactosamine

3.8

A gentle sugar-derived ingredient that supports skin renewal and surface smoothness, often used as a milder alternative to traditional exfoliants.

Irritation

low

Source

semi-synthetic

beautyskincarehumectant
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Humectant

Acetyl Glucosamine

Acetyl Glucosamine

4.2

A mild, sugar-based ingredient that helps gently exfoliate and hydrate skin without the harshness of stronger acids.

Irritation

low

Source

semi-synthetic

beautyskincarehumectant
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Humectant

Acetyl Glutamine

Acetyl Glutamine

4.0

Acetyl Glutamine is a gentle, water-loving amino acid derivative that helps keep skin plump and hydrated while supporting the skin's natural barrier.

Irritation

low

Source

semi-synthetic

beautyskincarehumectant
Read ingredient review

Skin conditioning agent

Acetyl Glycyl Beta-Alanine

Acetyl Glycyl Beta-Alanine

3.8

A gentle peptide that helps maintain skin hydration and firmness, but research is still early.

Irritation

low

Source

synthetic

beautyskincarepeptide
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Anti-aging agent

Acetyl Heptapeptide-19 Amide

ACETYL HEPTAPEPTIDE-19 AMIDE

4.0

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

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Heptapeptide-4

ACETYL HEPTAPEPTIDE-4

4.0

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

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Heptapeptide-9

ACETYL HEPTAPEPTIDE-9

4.0

A synthetic peptide that mimics natural signals to encourage firmer, smoother skin with low irritation risk.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Fragrance Ingredient

Acetyl Hexamethyl Indan

ACETYL HEXAMETHYL INDAN

3.5

A synthetic musk-like fragrance ingredient that is generally considered safe at low concentrations but offers no skincare benefit beyond scent.

Irritation

low

Source

synthetic

beautyskincarefragrance
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Fragrance Ingredient

Acetyl Hexamethyl Tetralin

ACETYL HEXAMETHYL TETRALIN

3.5

A common synthetic musk fragrance that adds a warm, sweet scent but has raised some environmental and allergen concerns.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Anti-aging agent

Acetyl Hexapeptide-1

ACETYL HEXAPEPTIDE-1

4.0

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

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Hexapeptide-19

Acetyl Hexapeptide-19

3.8

A synthetic peptide that may help soften expression lines and improve skin firmness, but research is still early.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging

Acetyl Hexapeptide-20

Acetyl Hexapeptide-20

3.8

A synthetic peptide that may help soften expression lines and improve skin firmness, but research is still early.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Hexapeptide-24

Acetyl Hexapeptide-24

4.0

A synthetic peptide that may help soften expression lines and improve skin firmness, but results are subtle and require consistent use.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging

Acetyl Hexapeptide-24 Amide

Acetyl Hexapeptide-24 Amide

4.0

A synthetic peptide that may help soften expression lines and support firmer-looking skin with low irritation risk.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Hexapeptide-30

Acetyl Hexapeptide-30

3.8

A synthetic peptide that may help support skin firmness and reduce fine lines, but human studies are limited.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Hexapeptide-31

ACETYL HEXAPEPTIDE-31

4.0

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

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Hexapeptide-37

Acetyl Hexapeptide-37

3.8

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-wrinkle agent

Acetyl Hexapeptide-38

Acetyl Hexapeptide-38

4.0

A synthetic peptide that temporarily softens expression lines by mimicking the action of a muscle-relaxing protein, offering a gentler alternative to injectables.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-wrinkle agent

Acetyl Hexapeptide-39

Acetyl Hexapeptide-39

4.0

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

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Hexapeptide-49

Acetyl Hexapeptide-49

4.0

A synthetic peptide that may help soften expression lines and improve skin firmness, but human data is still limited.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Hexapeptide-51 Amide

Acetyl Hexapeptide-51 Amide

4.0

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

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Acetyl Hexapeptide-7

Acetyl Hexapeptide-7

4.0

A gentle peptide that may help soften expression lines over time, but results are subtle and require consistent use.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-wrinkle agent

Acetyl Hexapeptide-8

Acetyl Hexapeptide-8

4.2

A popular peptide that can soften dynamic wrinkles by relaxing facial muscles, but results are subtle and temporary.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-wrinkle agent

Acetyl Hexapeptide-8 Amide

AMINOBUTYROYL HEXAPEPTIDE-8 AMIDE

4.0

A synthetic peptide that helps soften expression lines by temporarily relaxing facial muscles, with good safety profile but modest, temporary results.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

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
Read ingredient review

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
Read ingredient review

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
Read ingredient review

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
Read ingredient review

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