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

Soothing Agent

Manuka Leaf Water

Leptospermum Scoparium Branch/Flower/Leaf Water

4.0

A mild, naturally fragrant water from the manuka plant that can help soothe skin and provide antioxidant benefits without the intensity of essential oils.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Antimicrobial

Manuka Oil

Leptospermum Scoparium Branch/Leaf Oil

4.0

Manuka oil is a natural antimicrobial ingredient that can help calm blemishes, but it must be used at low concentrations to avoid skin irritation.

Irritation

moderate

Source

natural

beautyskincareantimicrobial
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Humectant

Maple Sap Extract

Acer Saccharum Sap Extract

4.0

A gentle, natural humectant that hydrates and soothes skin without clogging pores, ideal for sensitive and dry skin types.

Irritation

low

Source

natural

beautyskincarehumectant
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Antioxidant

Maqui Berry Extract

Aristotelia Chilensis Fruit Extract

4.0

Maqui berry extract is a gentle antioxidant that may help protect skin from pollution and UV damage, but more human studies are needed.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Maqui Berry Juice

ARISTOTELIA CHILENSIS FRUIT JUICE

4.0

Maqui berry juice is a gentle, antioxidant-rich ingredient that helps protect skin from environmental stress and may support a more even complexion.

Irritation

low

Source

natural

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Antioxidant

Maqui Berry Leaf Extract

Aristotelia Chilensis Leaf Extract

4.0

A gentle, antioxidant-rich leaf extract that may help protect skin from environmental stress and support a more even-looking complexion.

Irritation

low

Source

natural

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Emollient

Maqui Berry Seed Oil

ARISTOTELIA CHILENSIS SEED OIL

4.0

A gentle, antioxidant-packed oil that hydrates and protects without clogging pores, though research on its cosmetic benefits is still emerging.

Irritation

low

Source

natural

beautyskincareemollient
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Emollient

Mare Milk

MARE MILK

3.8

Mare milk is a gentle, nutrient-rich ingredient that hydrates and soothes skin, but research on its cosmetic benefits is still limited.

Irritation

low

Source

natural

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Emollient

Mare Milk Lipids

Mare Milk Lipids

3.8

A gentle, lipid-rich emollient that helps soften and condition the skin, but research on its unique benefits over other milk lipids is limited.

Irritation

low

Source

natural

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Exfoliant

Margarita Powder

Margarita Powder

3.0

A fun, fragrant exfoliant blend for body scrubs, but its high salt content can be drying and irritating for sensitive skin.

Irritation

moderate

Source

mixed

beautyskincareexfoliant
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Soothing agent

Marigold Extract

TAGETES PATULA FLOWER/LEAF/STEM EXTRACT

3.8

A gentle botanical extract that may help calm skin and fight free radicals, but research is still emerging.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Fragrance

Marigold Flower Oil

TAGETES PATULA FLOWER OIL

3.5

Marigold flower oil adds a pleasant floral scent and may offer mild antioxidant benefits, but it can be a skin sensitizer for some people.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Anti-aging agent

Marine Peptide Complex

SR-(Tripeptide-68, Mussel Polypeptide-1, Mussel Oligopeptide-1, Mussel Polypeptide-1, Dipeptide-40)

3.8

A marine-inspired peptide blend that may help plump and firm skin, but research is still emerging.

Irritation

low

Source

semi-synthetic

beautyskincarepeptide
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Emollient

Maripa Seed Butter

Attalea Maripa Seed Butter

4.0

A nourishing, plant-based butter that softens and smooths skin without feeling overly greasy.

Irritation

low

Source

natural

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Antioxidant

Maritime Pine Bark Extract

Pinus Pinaster Bark/Bud Extract

4.2

A gentle, plant-derived antioxidant that helps protect skin from environmental stress and may support a more even skin tone.

Irritation

low

Source

natural

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Antioxidant

Maritime Pine Bark Water

PINUS PINASTER BARK WATER

4.0

A gentle, antioxidant-rich water from maritime pine bark that helps soothe and protect skin from environmental stress.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antioxidant

Maritime Pine Extract

Pinus Pinaster Twig Leaf Extract

4.1

A gentle, plant-based antioxidant that helps protect skin from environmental stress and may support a more even complexion.

Irritation

low

Source

natural

beautyskincareantioxidant
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Fragrance

Marjoram Flower Oil

ORIGANUM MAJORANA FLOWER OIL

3.8

Marjoram flower oil offers a calming, aromatic experience with mild antioxidant benefits, but its fragrance components can be irritating for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Fragrance

Marjoram Herb Oil

ORIGANUM MAJORANA HERB OIL

3.8

Marjoram herb oil adds a warm herbal scent and mild antioxidant benefits, but it can irritate sensitive skin and is best used in low concentrations.

Irritation

moderate

Source

natural

beautyskincareessential oil
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Antioxidant

Marjoram Leaf Extract

ORIGANUM MAJORANA LEAF EXTRACT

3.8

A gentle botanical extract with antioxidant and soothing potential, but limited high-quality human studies for cosmetic benefits.

Irritation

low

Source

natural

beautyskincareantioxidant
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Fragrance

Marjoram Leaf Oil

ORIGANUM MAJORANA LEAF OIL

3.8

Marjoram leaf oil adds a warm herbal scent and may offer mild soothing benefits, but it can be irritating for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Soothing Agent

Marjoram Leaf Water

ORIGANUM MAJORANA LEAF WATER

3.8

A gentle, aromatic botanical water that may offer mild antioxidant and soothing benefits, but lacks strong clinical evidence for specific skincare effects.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Fragrance

Marjoram Oil

ORIGANUM MAJORANA FLOWER/LEAF/STEM OIL

3.8

Marjoram oil offers a pleasant herbal scent and potential antioxidant benefits, but its essential oil nature means it can be irritating for sensitive skin.

Irritation

moderate

Source

natural

beautyskincarefragrance
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Emollient

Marmot Oil

Marmota Oil

2.5

Marmot oil is a traditional animal fat used for its moisturizing properties, but it lacks modern safety and efficacy data and may not be suitable for all skin types.

Irritation

low

Source

natural

beautyskincareemollient
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Soothing Agent

Marram Root Extract

Ammophila Arenaria Root Extract

3.5

A gentle, plant-based extract that may help calm irritated skin, though research is still limited.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Antioxidant

Marsh Cinquefoil Extract

Hydrolyzed Comarum Palustre Root/Stem Extract

3.8

A gentle botanical extract with antioxidant and soothing potential, but research is limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Soothing Agent

Marshmallow Callus Extract

Althaea Officinalis Callus Culture Extract

4.0

A gentle, lab-grown plant extract that may help calm irritated skin and support hydration, though research is still emerging.

Irritation

low

Source

biotech

beautyskincaresoothing agent
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Soothing Agent

Marshmallow Root Extract

Althaea Officinalis Leaf/Root Extract

4.0

Marshmallow root extract is a gentle, plant-based ingredient that helps calm irritated skin and provides light hydration.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Soothing agent

Martagon Lily Bulb Extract

Lilium Martagon Bulb Extract

3.8

A gentle plant extract that may help calm skin and provide antioxidant support, though research is still limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Antioxidant

Marula Callus Extract

SCLEROCARYA BIRREA CALLUS EXTRACT

4.0

A lab-grown extract from marula tree cells that may help protect skin from environmental stress, though human studies are limited.

Irritation

low

Source

biotech

beautyskincareantioxidant
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Antioxidant

Marula Fruit Extract

Sclerocarya Birrea Fruit Extract

4.0

A gentle, antioxidant-rich fruit extract that helps protect skin from environmental stress and supports a healthy-looking complexion.

Irritation

low

Source

natural

beautyskincareantioxidant
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Emollient

Marula Oil PEG-8 Esters

Sclerocarya Birrea Seed Oil PEG-8 Esters

4.0

A gentle, water-soluble emollient derived from marula oil that hydrates and softens skin without clogging pores.

Irritation

low

Source

semi-synthetic

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Emulsifier

Marula Oil Polyglyceryl Esters

Sclerocarya Birrea Seed Oil Polyglyceryl-10 Esters

4.5

A mild, eco-friendly emulsifier that helps blend oil and water in your skincare while adding a touch of marula oil's nourishing properties.

Irritation

low

Source

semi-synthetic

beautyskincareemulsifier
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Emollient

Marula Oil Polyglyceryl-6 Esters

Sclerocarya Birrea Seed Oil Polyglyceryl-6 Esters

4.3

A gentle, eco-friendly emollient that hydrates and helps blend oil and water in formulas without clogging pores.

Irritation

low

Source

semi-synthetic

beautyskincareemollient
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Exfoliant

Marula Seed Powder

SCLEROCARYA BIRREA SEED POWDER

4.0

A gentle, natural exfoliating powder that helps smooth skin without harsh microbeads.

Irritation

low

Source

natural

beautyskincareexfoliant
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Antioxidant

Maslinic Acid

MASLINIC ACID

4.0

Maslinic acid is a gentle plant-derived antioxidant that helps protect skin from environmental stress and may support collagen health, though human studies are still limited.

Irritation

low

Source

natural

beautyskincareantioxidant
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Soothing Agent

Masterwort Leaf Extract

PEUCEDANUM OSTRUTHIUM LEAF EXTRACT

3.8

Masterwort Leaf Extract is a gentle botanical with potential soothing and antioxidant benefits, but research is limited and it's not a standout ingredient.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Soothing Agent

Mastic Gum Water

Pistacia Lentiscus Gum Water

4.0

A gentle, water-based extract from mastic tree resin that may help calm irritation and provide antioxidant protection.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Fragrance

Mastic Leaf Oil

Pistacia Lentiscus Leaf Oil

3.8

A fragrant essential oil with antioxidant potential, but may irritate sensitive skin and is best used in low concentrations.

Irritation

moderate

Source

natural

beautyskincareessential oil
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Emollient

Mastic Leaf Wax

Pistacia Lentiscus Leaf Wax

4.0

A gentle, plant-derived wax that adds structure and a smooth feel to balms and creams without common irritation.

Irritation

low

Source

natural

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Antioxidant

Mastic Thyme Extract

Thymus Mastichina Herb Extract

4.0

A gentle, plant-based antioxidant that helps protect skin from environmental stress while offering mild soothing benefits.

Irritation

low

Source

natural

beautyskincareantioxidant
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Antimicrobial

Mastic Thyme Flower Oil

THYMUS MASTICHINA FLOWER OIL

3.8

Mastic Thyme Flower Oil offers antimicrobial and antioxidant benefits but can be irritating for sensitive skin due to its essential oil nature.

Irritation

moderate

Source

natural

beautyskincareessential oil
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Antimicrobial

Mastic Thyme Oil

THYMUS MASTICHINA HERB OIL

3.8

Mastic thyme oil offers antimicrobial and antioxidant benefits but can be irritating for sensitive skin; use in low concentrations.

Irritation

moderate

Source

natural

beautyskincareessential oil
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Soothing agent

Matico Leaf Extract

Piper angustifolium leaf extract

3.8

A gentle botanical extract with antioxidant and soothing potential, but human skin research is still limited.

Irritation

low

Source

natural

beautyskincarebotanical extract
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Soothing agent

Matrine

MATRINE

4.0

Matrine is a plant-derived alkaloid that helps calm redness and irritation, making it a gentle option for sensitive or acne-prone skin.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Antioxidant

Matsutake Mushroom Ferment Extract

Tricholoma Matsutake Mycelium Ferment Extract

4.0

A gentle, antioxidant-rich ferment from a rare mushroom that may help calm skin and defend against environmental stress.

Irritation

low

Source

natural

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Antioxidant

Matsutake Mushroom Powder

Tricholoma Matsutake Powder

3.8

A gentle, antioxidant-rich mushroom powder that may help soothe and protect skin, though research is still emerging.

Irritation

low

Source

natural

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Emollient

Matthiola Longipetala Seed Oil

MATTHIOLA LONGIPETALA SEED OIL

4.0

A gentle, plant-based oil that helps soften and smooth skin without clogging pores, though research on its specific benefits is still limited.

Irritation

low

Source

natural

beautyskincareemollient
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Emollient

Mauloutchia Seed Butter

Mauloutchia Humblotii Seed Butter

4.0

A nourishing, plant-based butter from Madagascar that softens and conditions skin, but may be too rich for oily or acne-prone skin.

Irritation

low

Source

natural

beautyskincareemollient
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Soothing agent

Mayamaea Permit Extract

MAYAMAEA PERMITIS EXTRACT

3.8

A gentle microalgae extract that may help calm skin and fight oxidative stress, but research is still early.

Irritation

low

Source

natural

beautyskincaresoothing agent
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Preservative

MDM Hydantoin

MDM Hydantoin

3.5

MDM Hydantoin is an effective preservative but may irritate sensitive skin due to its slow release of formaldehyde.

Irritation

moderate

Source

synthetic

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Preservative

MEA O-Phenylphenate

MEA O-PHENYLPHENATE

3.5

A synthetic preservative that helps keep products fresh but may cause irritation in sensitive skin.

Irritation

moderate

Source

synthetic

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Surfactant

MEA PPG-6 Laureth-7 Carboxylate

MEA PPG-6 LAURETH-7 CARBOXYLATE

4.0

A gentle synthetic surfactant that helps cleanse and emulsify without stripping the skin's natural moisture barrier.

Irritation

low

Source

synthetic

beautyskincaresurfactant
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Preservative Booster

MEA-Benzoate

MEA-Benzoate

3.5

MEA-Benzoate is a synthetic preservative helper that extends shelf life but may cause irritation for sensitive skin.

Irritation

moderate

Source

synthetic

beautyskincarepreservative
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