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

Abrasive

Nephrite Powder

NEPHRITE POWDER

3.5

Nephrite powder is a natural mineral exfoliant with a long history in traditional beauty, but scientific evidence for its skin benefits is limited.

Irritation

moderate

Source

natural

beautyskincareabrasive
Read ingredient review

Soothing Agent

Nephthea Columnaris Extract

Nephthea Columnaris Extract

3.8

A gentle marine extract with antioxidant potential, but research is still early and sustainability is a concern.

Irritation

low

Source

natural

beautyskincaresoothing agent
Read ingredient review

Fragrance

Neral

Neral

3.5

Neral adds a bright lemon scent to products but can be a skin sensitizer, so it's best for those without fragrance sensitivities.

Irritation

moderate

Source

natural

beautyskincarefragrance
Read ingredient review

Fragrance

Nerol

NEROL

3.8

Nerol is a natural floral fragrance ingredient that adds a pleasant rose-like scent to products but offers no proven skincare benefits beyond aroma.

Irritation

low

Source

natural

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Nerol Oxide

NEROL OXIDE

3.5

Nerol Oxide is a synthetic fragrance ingredient that adds a pleasant floral-citrus note, but offers no skincare benefits and may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance

Nerolidol

NEROLIDOL

3.8

Nerolidol is a natural fragrance ingredient with some early research suggesting antioxidant and skin-soothing benefits, but its main role in cosmetics is scent.

Irritation

low

Source

natural

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Nerolidyl Acetate

NEROLIDYL ACETATE

3.8

Nerolidyl Acetate is a gentle, naturally derived fragrance ingredient with mild skin-conditioning potential, but its benefits are secondary to its scent profile.

Irritation

low

Source

natural

beautyskincarefragrance
Read ingredient review

Fragrance

Neryl Acetate

NERYL ACETATE

3.8

Neryl acetate is a gentle, naturally derived fragrance ingredient with low irritation potential, but it offers no active skincare benefits beyond scent and mild conditioning.

Irritation

low

Source

natural

beautyskincarefragrance
Read ingredient review

Fragrance

Neryl Butyrate

NERYL BUTYRATE

3.5

Neryl butyrate is a synthetic fragrance ester that adds a pleasant fruity-floral note to products, but offers no skincare benefits and may cause sensitivity in those with fragrance allergies.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance

Neryl Formate

NERYL FORMATE

3.5

Neryl Formate is a synthetic fragrance ingredient that adds a pleasant scent but offers no direct skincare benefits and may cause sensitivity in some individuals.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Neryl Isobutyrate

NERYL ISOBUTYRATE

3.5

Neryl isobutyrate is a synthetic fragrance ingredient that adds a floral, fruity scent to products; it is generally considered safe at low concentrations but offers no skin benefit beyond fragrance.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Neryl Isovalerate

Neryl Isovalerate

3.5

Neryl Isovalerate is a synthetic fragrance ingredient with a pleasant floral-herbal scent; it is considered safe at low concentrations but offers no skincare benefits beyond scent.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance Ingredient

Neryl Propionate

NERYL PROPIONATE

3.8

Neryl propionate is a synthetic fragrance ingredient that adds a pleasant floral scent to products; it is generally considered safe at low concentrations but offers no skincare benefits.

Irritation

low

Source

synthetic

beautyskincarefragrance
Read ingredient review

Fragrance

New Caledonian Sandalwood Oil

SANTALUM AUSTROCALEDONICUM WOOD OIL

3.8

A fragrant, soothing oil from New Caledonian sandalwood, but may cause irritation in sensitive skin due to its aromatic compounds.

Irritation

moderate

Source

natural

beautyskincarefragrance
Read ingredient review

Fragrance

New Caledonian Sandalwood Water

SANTALUM AUSTROCALEDONICUM WOOD WATER

4.0

A gentle, aromatic water from New Caledonian sandalwood that can soothe skin and provide a subtle fragrance, but its benefits are largely anecdotal and it may cause sensitivity in those allergic to sandalwood.

Irritation

low

Source

natural

beautyskincarefragrance
Read ingredient review

Soothing agent

New Jersey Tea Extract

CEANOTHUS AMERICANUS EXTRACT

3.8

A gentle botanical extract with soothing and antioxidant potential, but research is limited and it's not a standout ingredient.

Irritation

low

Source

natural

beautyskincarebotanical extract
Read ingredient review

Antioxidant

New Zealand Christmas Tree Extract

Metrosideros Excelsa Flower/Leaf Extract

4.0

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

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Soothing Agent

New Zealand Flax Extract

Phormium Tenax Extract

4.0

A gentle, antioxidant-rich botanical extract that may help calm redness and support skin barrier repair, though human clinical data is still limited.

Irritation

low

Source

natural

beautyskincarebotanical
Read ingredient review

Humectant

New Zealand Flax Leaf Water

Phormium Tenax Leaf Water

3.8

A gentle, hydrating botanical water with antioxidant properties, best for soothing and refreshing normal to dry skin.

Irritation

low

Source

natural

beautyskincarehumectant
Read ingredient review

Antioxidant

New Zealand Spinach Extract

Tetragonia tetragonoides extract

3.8

A gentle, antioxidant-rich plant extract that may help calm and protect skin, though research is still early.

Irritation

low

Source

natural

beautyskincareantioxidant
Read ingredient review

Skin Restorative

Niacin

Niacin

4.0

Niacin is a well-studied form of vitamin B3 that helps strengthen the skin barrier and even out skin tone, but it can cause temporary flushing in some people.

Irritation

low

Source

synthetic

beautyskincarevitamin
Read ingredient review

Humectant

Niacinamide

Niacinamide

4.5

A well-researched, multi-tasking vitamin that strengthens skin, fades dark spots, and calms redness without irritation.

Irritation

low

Source

synthetic

beautyskincarehumectant
Read ingredient review

Antioxidant

Niacinamide Ascorbate

Niacinamide Ascorbate

4.0

A gentle, stable hybrid of niacinamide and vitamin C that offers antioxidant protection and brightening without the irritation of pure L-ascorbic acid.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
Read ingredient review

Exfoliant

Niacinamide Glycolate

Niacinamide Glycolate

4.0

A gentle exfoliating and brightening ingredient that pairs niacinamide with glycolic acid for smoother, more even-toned skin with less sting.

Irritation

low

Source

semi-synthetic

beautyskincareexfoliantbrightening
Read ingredient review

Brightening Agent

Niacinamide Hydroxybenzoate

Niacinamide Hydroxybenzoate

4.0

A gentle, multitasking ingredient that pairs niacinamide’s brightening and barrier-supporting powers with mild exfoliating and soothing properties from hydroxybenzoate.

Irritation

low

Source

semi-synthetic

beautyskincarebrighteningantioxidant
Read ingredient review

Brightening Agent

Niacinamide Hydroxycitrate

Niacinamide Hydroxycitrate

3.8

A promising brightening ingredient that combines niacinamide with hydroxycitrate, but research is still limited compared to niacinamide alone.

Irritation

low

Source

semi-synthetic

beautyskincarebrightening agent
Read ingredient review

Humectant

Niacinamide Lactate

Niacinamide Lactate

4.3

A gentle dual-action ingredient that combines niacinamide's barrier support with lactic acid's mild exfoliation for smoother, brighter skin.

Irritation

low

Source

semi-synthetic

beautyskincarehumectantexfoliant
Read ingredient review

Brightening Agent

Niacinamide Malate

Niacinamide Malate

4.3

Niacinamide malate is a gentle, effective ingredient that helps brighten skin tone and improve texture without the irritation of stronger acids.

Irritation

low

Source

semi-synthetic

beautyskincarebrightening agent
Read ingredient review

Exfoliant

Niacinamide Mandelate

Niacinamide Mandelate

4.3

A gentle, dual-action ingredient that exfoliates and supports the skin barrier without the irritation of standalone acids.

Irritation

low

Source

semi-synthetic

beautyskincareexfolianthumectant
Read ingredient review

Exfoliant

Niacinamide Salicylate

Niacinamide Salicylate

4.0

A gentle exfoliating and brightening hybrid that pairs the pore-clearing power of salicylic acid with the soothing, barrier-supporting benefits of niacinamide.

Irritation

low

Source

semi-synthetic

beautyskincareexfoliantbrightening agent
Read ingredient review

Antioxidant

Niacinamide Thioctate

Niacinamide Thioctate

3.8

A promising hybrid antioxidant that combines niacinamide and alpha-lipoic acid, but research is still early.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
Read ingredient review

Skin conditioning agent

Niacinamide Yeast Ferment

NIACINAMIDE/YEAST POLYPEPTIDE

4.0

A gentle, multi-tasking ingredient that combines niacinamide's brightening and barrier-supporting benefits with yeast peptides for added hydration and skin-smoothing effects.

Irritation

low

Source

semi-synthetic

beautyskincarehumectantantioxidant
Read ingredient review

Soothing agent

Niaouli Flower/Leaf Extract

Melaleuca Leucadendron Viridiflora Flower/Leaf Extract

3.8

A gentle botanical extract from the niaouli tree that may help calm and purify skin, though research is limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
Read ingredient review

Fragrance

Niaouli Leaf Oil

Melaleuca quinquenervia leaf oil

3.8

Niaouli leaf oil is a natural essential oil with antimicrobial and soothing properties, but it can be irritating for sensitive skin and should be used in low concentrations.

Irritation

moderate

Source

natural

beautyskincareessential oil
Read ingredient review

Antimicrobial

Niaouli Oil

MELALEUCA VIRIDIFLORA LEAF OIL

3.8

Niaouli oil can help calm blemishes and add a fresh scent, but it may irritate sensitive skin if used at high concentrations.

Irritation

moderate

Source

natural

beautyskincareessential oil
Read ingredient review

Anti-irritant

Nickel Acetylmethionate

NICKEL ACETYLMETHIONATE

2.5

Nickel Acetylmethionate is a controversial ingredient that may soothe skin but carries risks due to nickel content, especially for those with nickel allergies.

Irritation

moderate

Source

synthetic

beautyskincareanti-irritant
Read ingredient review

Colorant

Nickel Gluconate

Nickel Gluconate

1.5

Nickel gluconate is a known allergen and sensitizer; it is rarely used in modern skincare and is best avoided, especially for anyone with nickel allergy.

Irritation

moderate

Source

synthetic

beautyskincarecolorant
Read ingredient review

Anti-aging agent

Nicotiana Benthamiana Oligopeptide-1

Nicotiana Benthamiana RH-Oligopeptide-1

3.8

A biotech-derived peptide from tobacco plants that may help firm skin and soften fine lines, but human research is still limited.

Irritation

low

Source

biotech

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Nicotiana Benthamiana Peptide Complex

Nicotiana Benthamiana Hexapeptide-40, Sh-Polypeptide-9

3.8

A plant-derived peptide blend that may help support skin firmness and reduce fine lines, but research is still early.

Irritation

low

Source

biotech

beautyskincareanti-aging
Read ingredient review

Skin conditioning agent

Nicotinaldehyde

Nicotinaldehyde

3.5

Nicotinaldehyde is a lesser-known relative of niacinamide that may help with skin texture and tone, but research is still early and it can be irritating for some.

Irritation

moderate

Source

synthetic

beautyskincareactive
Read ingredient review

Anti-aging agent

Nicotinamide Adenine Dinucleotide

Nicotinamide Adenine Dinucleotide

3.8

NAD+ is a buzzworthy anti-aging ingredient that supports skin cell energy and repair, but its topical benefits are still being studied and may not match the hype.

Irritation

low

Source

biotech

beautyskincareanti-aging
Read ingredient review

Anti-aging agent

Nicotinamide Mononucleotide

Nicotinamide Mononucleotide

3.8

A promising anti-aging ingredient that boosts cellular energy, but human skin research is still limited compared to niacinamide.

Irritation

low

Source

biotech

beautyskincareanti-aging
Read ingredient review

Antioxidant

Nicotinoyl Ascorbyl Succinate

Nicotinoyl PEG-4 Ethylascorbyl Succinate

4.3

A stable, dual-action antioxidant that combines vitamin C and niacinamide benefits without the typical irritation or instability of pure L-ascorbic acid.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
Read ingredient review

Anti-aging agent

Nicotinoyl Dipeptide-22

Nicotinoyl Dipeptide-22

4.0

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

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-aging agent

Nicotinoyl Dipeptide-23

Nicotinoyl Dipeptide-23

4.0

A lab-made peptide that may help smooth wrinkles and firm skin, but human studies are still limited.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-aging agent

Nicotinoyl Dipeptide-24

Nicotinoyl Dipeptide-24

4.0

A synthetic peptide that may help improve skin firmness and reduce fine lines, but more human studies are needed.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Nicotinoyl Dipeptide-26

Nicotinoyl Dipeptide-26

4.0

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

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Nicotinoyl Hexapeptide-44

Nicotinoyl Hexapeptide-44

4.0

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

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Nicotinoyl Hexapeptide-45

Nicotinoyl Hexapeptide-45

4.0

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

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-aging agent

Nicotinoyl Hexapeptide-56

Nicotinoyl Hexapeptide-56

4.0

A synthetic peptide that may help support collagen and reduce fine lines, but human data is still limited.

Irritation

low

Source

synthetic

beautyskincarepeptide
Read ingredient review

Anti-aging agent

Nicotinoyl Octapeptide-13

Nicotinoyl Octapeptide-13

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

Anti-aging agent

Nicotinoyl Octapeptide-9

Nicotinoyl Octapeptide-9

4.0

A lab-made peptide that may help smooth wrinkles and improve skin firmness, with low irritation potential.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Antioxidant

Nicotinoyl PEG-5 Tocopheryl Succinate

NICOTINOYL PEG-5 TOCOPHERYL SUCCINATE

4.0

A gentle, multi-tasking molecule that pairs niacinamide-like benefits with vitamin E’s antioxidant power, but research is still emerging.

Irritation

low

Source

semi-synthetic

beautyskincareantioxidant
Read ingredient review

Anti-Aging Agent

Nicotinoyl Pentapeptide-20

Nicotinoyl Pentapeptide-20

4.0

A promising anti-aging peptide that combines the benefits of niacinamide with a signal peptide to help firm skin and soften wrinkles.

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review

Anti-aging agent

Nicotinoyl Pentapeptide-33

Nicotinoyl Pentapeptide-33

4.0

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

Irritation

low

Source

synthetic

beautyskincareanti-aging
Read ingredient review