The library

Ingredient library

Every ingredient SkinAtlas knows about — all 2277 of them. What each one does, what it works well with, and what to watch for.

All 2277 ingredients — page 42 of 95

Humectant
Hydroxypropyltrimonium Hyaluronate

A cationic quaternary-ammonium derivative of hyaluronic acid that binds electrostatically to negatively charged skin proteins, delivering sustained surface hydration.

humectantfilm-former
Electrostatically adheres to skin surface for longer-lasting hydration than standard HAForms a breathable moisture-retaining filmSupports the skin barrier and may help reduce TEWL
Other
Hydroxypropyltrimonium Maltodextrin Crosspolymer

A quaternized crosslinked maltodextrin polymer; forms a cationic conditioning film on skin that improves texture and provides a silky, smooth feel in premium serums.

film-formingskin-conditioningtexture-modifier
Cationic crosslinked maltodextrin polymer that forms a conditioning film on skinCreates a smooth, velvety after-feel in serums and ampoules
Other
Hydroxystearic Acid

A hydroxy fatty acid derived from castor oil used as a gelling and thickening agent in creams and sticks. Contributes minor emollient properties to formulas.

viscosity-increasingemollientskin-conditioning
Provides structure to cream and balm formulas
Other
Hydroxyundecanoic Acid
HYDROXYUNDECANOIC ACID

A hydroxy fatty acid derivative. Has mild antimicrobial properties. Used in Kanebo's Skin Harmonizer for conditioning and microbiome-supporting effects.

antimicrobialskin-conditioning
Mild antimicrobial activitySkin conditioning
+ Glycerin
Antioxidant
Hypericum Erectum Extract
HYPERICUM ERECTUM EXTRACT

An extract from Hypericum erectum (Japanese St. John's Wort). Contains hypericin, pseudohypericin, and quercetin derivatives with antioxidant and soothing properties. Widely used in Elixir and other Shiseido brands.

antioxidantsoothingskin-conditioning
Antioxidant protection via hypericin and flavonoidsMild soothing and anti-inflammatory effectTraditional Japanese botanical
May cause photosensitivity at very high concentrations (same class as Hypericum perforatum)
+ Melilotus Officinalis Extract+ Tocopherol
Soothing
Hypericum Perforatum Extract
HYPERICUM PERFORATUM FLOWER/LEAF/STEM EXTRACT

Extract from St. John's wort (Hypericum perforatum). Contains hypericin, hyperforin, flavonoids, and tannins with anti-inflammatory, antioxidant, and soothing properties. Used in European cosmetics for skin calming.

soothingantioxidantskin-conditioning
Anti-inflammatory and soothingAntioxidant-rich (hypericin, hyperforin)Traditional wound-healing herb
Topical photosensitivity reported with high concentrations of whole plant extract
+ Allantoin+ Bisabolol
Humectant
Hypnea Musciformis Extract

An extract from Hypnea musciformis, a red macroalga, used as a humectant and skin-conditioning agent in cosmetics for its carrageenan content and antioxidant properties.

humectantsoothingantioxidantskin-conditioning
Attracts and retains moisture via marine polysaccharides (carrageenans)Antioxidant activity from marine pigmentsMild soothing and conditioning properties
Preservative
Hypochlorous Acid
HYPOCHLOROUS ACID

A weak acid naturally produced by white blood cells to fight infection. In skincare (notably Tower 28 SOS Spray) it is generated by electrolyzing saline; antimicrobial and calming with near-zero irritation.

antimicrobialanti-inflammatory
Kills bacteria, fungi, and viruses on contact without disrupting the skin barrierCalms redness and post-acne inflammationProduced naturally by white blood cells — exceptional skin tolerance
Can oxidize other actives in the same formula; usually formulated at low concentration
+ Sodium Chloride
Antioxidant
Hyssop Extract
Hyssopus Officinalis Extract

An extract from hyssop (Hyssopus officinalis) herb rich in flavonoids and phenolic acids with antioxidant and mild soothing properties.

antioxidantsoothing
Antioxidant protection via flavonoids and diterpenoidsSoothes and calms skin
Antioxidant
Ilex Paraguariensis Leaf Extract

Leaf extract from Ilex paraguariensis (yerba mate), a South American plant rich in xanthines (caffeine, theobromine) and chlorogenic acid antioxidants.

antioxidantskin-conditioning
Rich in caffeine, theobromine, chlorogenic acids, and polyphenols from yerba mate leavesStrong antioxidant protection and mild skin-firming effect
Soothing
Illicium Verum (Anise) Fruit Extract
Illicium Verum Fruit Extract

An extract from the dried fruit of Illicium verum (star anise), containing polyphenols, flavonoids, and anethole; used in cosmetics for its mild soothing and antioxidant properties.

soothingantioxidantskin-conditioning
Soothes mild inflammation and irritationAntioxidant protection from polyphenols and flavonoidsMild skin-conditioning effect
Contains anethole which can irritate sensitive skin at elevated concentrations; well-tolerated at typical cosmetic use levels
Humectant
Imperata Cylindrica Root Extract

A desert-grass root extract valued for binding moisture and supporting hydration.

humectant
Hydration
Soothing
Indigofera Tinctoria Extract

A botanical extract from the Indigofera tinctoria (true indigo) plant containing active compounds indirubin and tryptanthrin, used in skincare for anti-inflammatory, soothing, and antioxidant properties.

soothinganti-inflammatoryantioxidantantimicrobial
Reduces skin redness and irritation via anti-inflammatory compounds indirubin and tryptanthrinSupports skin barrier by promoting filaggrin productionProvides antioxidant protection against free radicals
Weak sensitization potential noted by SCCS — patch test recommended for sensitive skinRaw indigo powder (not extract) may cause temporary skin tinting; extract form is milder
Antioxidant
Inonotus Obliquus (Mushroom) Extract
INONOTUS OBLIQUUS EXTRACT

Extract from Inonotus obliquus (Chaga), a parasitic polypore mushroom that grows primarily on birch trees in cold Northern climates. The sclerotium is exceptionally dense in antioxidant compounds: beta-glucans, melanins, betulinic acid absorbed from the birch host, inotodiol, and polyphenols. Used in K-beauty anti-aging formulas targeting oxidative stress and free-radical skin damage.

antioxidantskin-conditioningbrighteninganti-aging
Exceptionally high antioxidant activity — Chaga has among the highest ORAC values of any natural materialRich in beta-glucans (immunomodulating polysaccharides), betulinic acid (from birch host), and melanin pigmentsBetulinic acid demonstrates anti-inflammatory and potential anti-tumor activity in published studies
+ Beta-Glucan+ Tocopherol+ Niacinamide
Humectant
Inositol

A naturally occurring cyclohexane polyol (commonly myo-inositol) found in cell membranes, used in cosmetics as a humectant and skin-conditioning agent.

humectantskin-conditioningcell-signaling
Attracts and retains moisture as a polyol humectantSupports skin barrier functionInvolved in cell membrane signaling pathways
Other
Inulin Lauryl Carbamate
INULIN LAURYL CARBAMATE

A lauroyl ester of inulin, a plant-derived polysaccharide (fructan). Functions as a film-former and has prebiotic properties that support the skin microbiome. Creates a powdery, velvety skin feel. Used in Sana's eye cream.

film-formerskin-conditioningprebiotic
Film-forming — creates a smooth, soft-focus skin effectPrebiotic — supports healthy skin microbiomeDerived from natural inulin (plant fiber)
+ Glycerin+ Lactobacillus Ferment
Emollient
Inulin Stearate

An ester of inulin (a fructan polysaccharide from chicory or agave) and stearic acid. It acts as a film-forming emollient, depositing a light conditioning layer on skin. The inulin backbone may also offer mild prebiotic-adjacent effects on the skin microbiome, though cosmetic evidence is limited.

emollientfilm-formerskin-conditioning agentprebiotic-type ingredient
Forms a thin, smooth film on skin that improves texture and reduces water lossDerived from plant-origin inulin (chicory); naturally sourcedProvides a dry, silky skin feel without greasiness
Preservative
Iodopropynyl Butylcarbamate

An iodine-containing organic preservative with strong antifungal and antibacterial activity. Used as a co-preservative at very low concentrations. Subject to strict concentration limits under EU Cosmetics Regulation.

preservativeantifungal
Highly effective broad-spectrum preservative (especially antifungal) active against molds, yeasts, and bacteria at very low concentrations (0.02–0.1%)
Strong sensitizer — EU restricts to 0.02% in leave-on face products; banned in lip products and products for children under 3Associated with allergic contact dermatitis; considered a high-concern preservative
Soothing
Iris Florentina Root Extract
IRIS FLORENTINA ROOT EXTRACT

An extract from the rhizome (root) of Iris florentina (white iris/orris). Contains iridoids (irisin), isoflavones, and flavonoids that provide soothing, antioxidant, and conditioning properties.

soothingskin-conditioningantioxidant
Gentle skin conditioning and soothingContains isoflavones and iridoidsLuxury botanical in prestige skincare
+ Rosa Canina Fruit Extract+ Fagus Sylvatica Bud Extract
Antioxidant
Iris Germanica Root Extract
IRIS GERMANICA ROOT EXTRACT

Extract from the rhizome of Iris germanica (German iris / orris root). Contains irisone, flavonoids, and phenolic compounds with antioxidant and mild skin-brightening properties. Used in brightening and anti-aging formulations.

antioxidantskin-brighteningskin-conditioning
Antioxidant and anti-inflammatoryTyrosinase-inhibiting properties (skin brightening)Rich in isoflavones
+ Tranexamic Acid+ Niacinamide
Antioxidant
Iris Versicolor Extract

An extract from the blue flag iris (Iris versicolor) containing isoflavones and flavonoid polyphenols used for antioxidant and brightening benefits.

antioxidantsoothingbrightening
Antioxidant protection via isoflavones and flavonoidsSoothes skinBrightening support
Other
Iron Oxides

Inorganic mineral pigments (red, yellow, and black iron oxides) used as colorants in cosmetics including tinted sunscreens, CC creams, and foundation.

colorantopacifier
Provides color and opacity to cosmetic formulas
Soothing
Isatis Tinctoria Leaf Extract
ISATIS TINCTORIA LEAF EXTRACT

Extract from the leaves of Isatis tinctoria (woad/Chinese indigo), a plant used in traditional Chinese and European medicine. Contains glucobrassicin, flavonoids, and alkaloids. Used for its soothing and anti-inflammatory properties.

soothingantioxidantskin-conditioning
Anti-inflammatory and soothingTraditional Chinese medicine botanicalAntioxidant protection
+ Allantoin+ Dipotassium Glycyrrhizate
Emollient
Isoamyl Laurate

A synthetic ester of isoamyl alcohol and lauric acid used as a lightweight, fast-spreading emollient and solvent in cleansing oils, serums, and moisturizers.

emollientsolventskin-conditioning
Lightweight, dry-touch emollient feelDissolves and disperses other ingredientsImproves spreadability and skin absorption