Skincare Ingredient Glossary
What's actually in your skincare — explained in plain English, without the fear-mongering.
2-Oleamido-1,3-Octadecanediol
Ceramide-like barrier lipid
A lab-made lipid built to resemble the skin's own ceramides — often called a "pseudo-ceramide". It slots into the skin's outer layer to help reinforce the barrier and reduce moisture loss, much like ceramides do, though it is a different molecule. Gentle and suitable for dry and sensitive skin.
Acetyl Glucosamine
Brightening & hydrating amino sugar
An amino sugar that hydrates and can help with the look of uneven tone. Often paired with niacinamide for a brightening effect. Gentle and well tolerated.
Adenosine
Smoothing & anti-wrinkle
A compound found naturally in every living cell. Studies suggest it can help smooth the look of fine lines and support skin recovery, and it is a registered anti-wrinkle ingredient in Korea — which is why it appears in so much K-beauty. Gentle and suitable for most skin types.
Alcohol Denat.
Solvent & texture aid
A drying alcohol sometimes used to improve product texture and help ingredients absorb quickly. Higher concentrations may be drying for some skin types.
Algae & Seaweed Extracts
Hydrating marine extracts
Extracts from algae and seaweed, rich in minerals and polysaccharides that hydrate, soften and help soothe the skin. Generally gentle.
Allantoin
Soothing & skin-conditioning
A gentle ingredient that soothes, softens and helps skin feel comfortable. Often used in products for sensitive or irritated skin.
Aloe Vera
Soothing & hydrating botanical
A water-rich plant extract long used to calm, cool and lightly hydrate skin. Gentle and popular in products for irritated or post-sun skin.
Alpha Arbutin
Brightening & dark spots
A brightening ingredient related to arbutin, which occurs naturally in bearberry leaves; the alpha form used in skincare is usually made biotechnologically. It slows the enzyme that makes melanin, helping fade the look of dark spots and uneven tone over several weeks. Gentle and well tolerated, which makes it a popular alternative to stronger brighteners.
Aluminium Hydroxide
Coating & texture aid
A mineral used to coat pigments and mineral sunscreen filters such as titanium dioxide so they spread evenly and stay stable, and to make products more opaque. It is not the same as the aluminium salts used in antiperspirants and is considered inert on skin.
Amino Acids
Hydration & barrier support
Building blocks of proteins that hydrate skin and support its natural moisturising factor and barrier. Gentle and well tolerated.
Artemia Extract
Skin-conditioning marine extract
An extract of artemia, a tiny brine shrimp found in sea plankton. Brands use it as a conditioning ingredient said to help skin cope with environmental stress such as sun and pollution; most of the evidence comes from ingredient-supplier studies. Gentle — but animal-derived, which is worth knowing if you avoid animal ingredients.
Azelaic Acid
Anti-blemish & tone-evening acid
A gentle acid that helps keep pores clear, calms the look of redness and evens out dark marks. Often chosen for blemish-prone and redness-prone skin. It can tingle or itch at first, which usually settles with use.
Bakuchiol
Gentle retinol alternative
A plant compound from the babchi (Psoralea corylifolia) seed. Studies suggest it can soften the look of fine lines and improve texture in a similar way to retinol, but with less dryness and irritation — and it is not sensitising to sunlight. A good option for sensitive skin.
Beeswax
Protective wax
Beeswax (cera alba) is made by honeybees; it thickens balms and creams and leaves a light protective film that slows moisture loss. It is not vegan. “Synthetic beeswax” is a lab-made blend of fatty esters and acids designed to behave like beeswax — it contains no bee products. Both are generally well tolerated.
Behentrimonium Methosulfate
Conditioning emulsifier
A conditioning ingredient made from rapeseed (canola) oil that helps oil and water blend and leaves skin feeling soft and smooth rather than tacky. Despite the name, it is not a sulfate cleanser and does not strip the skin. Common in creams and lotions and considered mild.
Beta-Glucan
Soothing & hydrating
A sugar found in oats, mushrooms and yeast. It forms a light, moisturising film, helps calm redness and supports the skin's recovery — often compared to hyaluronic acid for hydration. Very gentle.
Betaine
Humectant & soothing agent
A naturally occurring amino-acid derivative, usually from sugar beet, that draws water into the skin and helps it hold on to it. It also softens the feel of cleansers and can help reduce irritation. Gentle and well tolerated.
BHT
Antioxidant preservative
Used in very small amounts to stop the oils in a formula from going rancid, keeping products fresh. Considered safe at cosmetic levels.
Bisabolol
Soothing botanical
A calming compound originally derived from chamomile. Helps soothe redness and irritation and is well suited to sensitive or reactive skin.
Botanical Extracts
Plant extracts
A range of plant-derived extracts (herbs, roots, grains and seeds) used for their antioxidant, soothing and conditioning properties. Most are gentle, though botanicals can occasionally sensitise reactive skin.
Butylene Glycol
Humectant & solvent
A lightweight humectant and solvent that helps other ingredients dissolve and improves a product's texture. Also draws a little moisture into the skin.
Caffeine
Antioxidant & de-puffing
An antioxidant that temporarily tightens and de-puffs skin by constricting blood vessels. Often found in eye products to reduce the look of puffiness and dark circles.
Caprylyl Glycol
Humectant & preservative booster
A skin-conditioning humectant that also boosts the effectiveness of preservatives, allowing formulas to use less of them. Generally very well tolerated.
Carbomer
Thickener & gel former
A polymer used in tiny amounts to thicken formulas and create smooth gels and lotions. No active benefit, but very low-risk.
Centella Asiatica
Soothing & healing
Also known as Cica. A soothing botanical extract known for its calming and skin-repair properties. Popular in products for sensitive or irritated skin.
Ceramides
Barrier repair & protection
Essential lipids that make up a large part of the skin's natural barrier. Help protect against moisture loss and environmental damage.
Charcoal
Purifying & oil-absorbing
A porous powder that absorbs excess oil and helps lift away dirt and impurities, used in cleansers, masks and scrubs. It works at the surface of the skin and is rinsed away. Gentle, though very oily-skin formulas can feel drying.
Chemical UV Filters
Sunscreen UV filters
Organic filters that absorb UV light to protect skin from sun damage, used in many SPF products. Effective and widely used; a minority of people with reactive skin find some filters sensitising.
Cholesterol
Skin-identical lipid
A lipid naturally found in the skin barrier. Added to skincare to help reinforce the barrier and keep skin soft and resilient — often alongside ceramides and fatty acids.
Citric Acid
pH adjuster
Used in small amounts to balance a product's pH so it sits comfortably on skin. At these low levels it is not acting as an exfoliating acid.
Cleansing Surfactants
Cleansing agents
Surfactants that lift away oil, dirt and makeup and create lather in cleansers. Modern blends are mostly mild; high-foaming sulfates can feel stripping on dry or sensitive skin.
Collagen
Hydrating & smoothing film
A protein that, applied to the skin, sits on the surface: it is too large to rebuild the skin's own collagen, but it holds moisture and forms a smooth, plumping film. Usually animal- or marine-derived; vegan versions exist. Gentle.
Cucumber Extract
Soothing botanical
A water-rich botanical traditionally used to refresh and calm the skin. Light and gentle, with a mild soothing effect.
Dextran
Hydrating sugar polymer
A natural polysaccharide — a chain of glucose units — produced by fermenting sugar. It holds moisture, forms a light, smooth film on the skin and is often used as a carrier for actives such as peptides. Gentle for all skin types.
Dimethicone
Silicone emollient & smoother
A silicone that gives products a silky slip and forms a breathable layer to smooth skin and reduce moisture loss. Non-comedogenic for most, though some prefer to avoid silicones.
Dimethylmethoxy Chromanol
Antioxidant
A synthetic antioxidant, structurally related to vitamin E, that helps protect skin from free-radical damage caused by UV and pollution. Used in small amounts and generally well tolerated.
Disodium EDTA
Chelator & stabiliser
Used in tiny amounts to bind trace metals in water, which keeps products stable and helps preservatives work. No skincare benefit on its own, but very low-risk.
Ectoin
Protective & soothing
A molecule produced by microorganisms that survive extreme heat, salt and dryness. In skincare it helps hold water in the skin and supports the barrier against environmental stress, with soothing benefits for dry, reactive skin. Very gentle.
Emollient Esters & Plant Oils
Emollient & skin softener
Lightweight oils and esters that smooth, soften and condition the skin's surface. Caprylic/capric triglyceride (from coconut) and plant oils are common, well-tolerated examples.
Emulsifiers
Emulsifier (PEG-free)
Ingredients that let oil and water mix into a stable cream or lotion. This group covers PEG-free emulsifiers such as sugar-based glucosides, polyglyceryl and sorbitan esters, and potassium cetyl phosphate. Used in small amounts and generally well tolerated.
Enzyme Preservative System
Enzyme-based preservation
Enzymes such as glucose oxidase and lactoperoxidase that, together with glucose, generate tiny amounts of antimicrobial compounds to help keep a product fresh. The system is modelled on a natural defence found in milk and saliva and lets brands rely less on conventional preservatives. Gentle.
Ergothioneine
Antioxidant
An antioxidant amino acid found in mushrooms. It helps protect skin from the oxidative stress caused by UV and pollution and is often paired with vitamins C and E. Gentle and well tolerated.
Erythritol
Humectant
A sugar alcohol that draws water into the skin, much like glycerin and sorbitol. It is used in moisture-focused formulas and sheet masks to boost hydration. Gentle.
Essential Oils
Scent & botanical character
Concentrated aromatic oils distilled or pressed from flowers, leaves, peels and herbs — such as bergamot, geranium, lavender and sage. They give products their scent and some have antioxidant properties, but they are also a common source of fragrance sensitivity, so people with reactive skin often prefer to avoid them.
Ethylbisiminomethylguaiacol Manganese Chloride
Antioxidant
A lab-made antioxidant, also known as EUK-134, that mimics the skin's own antioxidant enzymes to help neutralise free radicals generated by UV and pollution. Used in very small amounts and considered well tolerated.
Fatty Alcohols (Cetyl / Cetearyl)
Emollient & thickener
Despite the name, these are waxy fatty alcohols that soften skin and thicken creams — the opposite of drying alcohols like Alcohol Denat. Non-irritating for most skin types.
Ferment & Yeast Extracts
Conditioning ferment extracts
Extracts produced by fermenting yeast or bacteria, used to condition skin and provide antioxidant and soothing benefits. Generally well tolerated.
Film Formers & Texturisers
Texture & smoothing agents
Polymers that give products a smooth feel, help them stay put, or form a soft-focus film on the skin. Inert and low-risk; polyethylene also appears as gentle scrub beads.
Fragrance / Parfum
Scent additive
Added for scent. Can be synthetic or natural. Some people with sensitive skin prefer to avoid fragrance as it can be a source of irritation.
Fragrance Allergens
Fragrance components
Individual scent molecules — like linalool, limonene and citronellol — that occur naturally in essential oils and are also used in fragrance blends. EU and UK rules require them to be named on the label above a small threshold because some people react to them, and an expanded EU list adopted in 2023 adds more, such as linalyl acetate, terpineol and carvone. Most people tolerate them fine; if you have fragrance-sensitive skin, they are worth watching for.
Ginseng
Antioxidant & revitalising
A root used in traditional Korean and Chinese medicine. Its extracts are rich in antioxidants called ginsenosides, which help defend skin against environmental stress and support a brighter, healthier-looking complexion. Gentle.
Gluconolactone (PHA)
Gentle exfoliation
A polyhydroxy acid (PHA) that exfoliates the surface of the skin more gently than AHAs like glycolic acid, because its larger molecules penetrate more slowly. It also attracts moisture and has antioxidant properties, making it a common choice for sensitive skin.
Glucose
Humectant sugar
A simple sugar that attracts water and helps keep skin hydrated, much like glycerin. In some formulas it is also part of an enzyme preservative system, where it fuels the enzymes that help keep the product fresh. Gentle and well tolerated.
Glycerin
Humectant & moisturiser
One of the most common and effective humectants in skincare. Draws water to the skin and helps maintain its moisture levels.
Glyceryl Caprylate
Emollient & preservative booster
A gentle ester of glycerin and caprylic acid, usually from coconut or palm. It softens skin, helps blend oil and water, and has antimicrobial properties that let brands use less conventional preservative. Generally well tolerated.
Glyceryl Glucoside
Hydration booster
Glycerin bonded to glucose, inspired by a compound that helps desert plants survive drought. It is a humectant that helps skin hold water, and studies suggest it may support the skin's own moisture channels. Gentle for all skin types.
Glyceryl Stearate
Emulsifier & emollient
Keeps the oil and water parts of a cream blended while softening the skin. A workhorse ingredient that improves texture; low irritation risk.
Glycol Distearate
Pearlising agent
A wax-like ester that gives cleansers and washes a pearly, opaque look and a creamier feel. Rinsed off and considered mild.
Glycolic Acid
Exfoliant & resurfacing
An alpha-hydroxy acid (AHA) that exfoliates the skin's surface, improving texture and tone. Sun sensitivity may increase with regular use.
Glycols (Humectant Solvents)
Humectant & solvent
A family of small glycols that help ingredients dissolve, improve texture and add light hydration. Some also boost preservation. Generally well tolerated, though a few people find certain glycols mildly sensitising.
Green Tea Extract
Antioxidant & soothing botanical
A botanical rich in polyphenol antioxidants that help calm skin and defend against environmental stress. Gentle and widely used.
Honey
Humectant & soothing
A natural humectant that draws moisture into the skin and has mild antibacterial and soothing properties. It leaves skin feeling soft and is common in masks. Gentle for most people, though it is animal-derived.
Hyaluronic Acid
Hydration & moisture retention
A powerful humectant that draws and holds moisture in the skin. Found naturally in the body, it helps keep skin looking plump and hydrated. Sodium hyaluronate is its smaller, more easily absorbed salt form.
Hydrolysed Plant Proteins
Conditioning & film-forming
Plant proteins broken into smaller pieces so they dissolve in formulas. They form a light, moisture-holding film that leaves skin feeling smoother. Gentle; people with a known wheat or soy allergy may want to check the source.
Hydroxyethyl Urea
Humectant
A gentle humectant that hydrates the skin, related to the skin's own natural moisturising factors. Suited to dry and sensitive skin.
Iron Oxides
Mineral colourant
Mineral pigments that give tinted products their colour. Stable, inert and among the gentlest colourants used in skincare and tinted SPF.
Isododecane
Lightweight emollient & spreadability
A fast-spreading, weightless emollient that gives products a silky, non-greasy glide and helps them dry down quickly. Generally well tolerated.
Isothiazolinone Preservatives
Preservative
Effective preservatives that are also among the more common contact allergens, especially in leave-on products. People with reactive or allergy-prone skin often prefer to avoid them.
Lactic Acid
Gentle AHA exfoliant
An alpha-hydroxy acid (AHA) that exfoliates the surface while also being mildly hydrating — generally gentler than glycolic acid. Sun sensitivity may increase with use.
Lanolin
Rich animal-derived emollient
A waxy substance from sheep’s wool (lanolin alcohol is a fraction of it, sometimes labelled “wool alcohols”). It softens skin and seals in moisture, which makes it useful for very dry or chapped skin. It is not plant-based, so it is unsuitable for vegans, and wool alcohols are a recognised contact allergen — if you have reacted to lanolin before, check labels for it.
Lauroyl Lysine
Silky texture powder
The amino acid lysine combined with lauric acid from coconut, used as a fine powder that gives a silky, smooth feel and helps pigments and other powders stay put. Gentle.
Lecithin
Emollient & emulsifier
A phospholipid (often soy-derived) that helps blend oil and water and conditions the skin barrier. Skin-friendly and widely used.
Licorice Extract
Soothing & brightening botanical
A botanical extract that calms the skin and can help soften the look of uneven tone and dark marks. Gentle and antioxidant-rich.
Magnesium Ascorbyl Phosphate
Vitamin C derivative & brightening
A stable, water-soluble form of Vitamin C. Gentler than pure ascorbic acid, it offers antioxidant and brightening benefits with less risk of irritation.
Maltodextrin & Cyclodextrin
Binders & carriers
Sugars made from starch. Maltodextrin helps bind, thicken and form a light film; cyclodextrin is a ring-shaped sugar that can hold other ingredients — or odours — inside it, helping to stabilise actives and release them gradually. Both are inert and well tolerated.
Mandelic Acid
Gentle AHA exfoliation
An alpha hydroxy acid (AHA) from bitter almonds. Its larger molecule penetrates more slowly than glycolic acid, so it exfoliates more gently — a common pick for sensitive or darker skin tones prone to marks. Use sunscreen during the day.
Mica
Shimmer & colourant
A mineral that adds a subtle shimmer or soft-focus glow. Inert and sits on the skin's surface. Generally very well tolerated.
Mild Preservatives
Preservative
A group of mild preservatives used in small amounts, often together, to keep products free of bacteria and mould. Low irritation risk at permitted levels.
Mineral & Synthetic Waxes
Structure & protection
Waxes refined from minerals or made in the lab, used to give balms, sticks and rich creams their structure and to form a protective layer that slows moisture loss. Highly purified and inert; very rich textures can feel heavy on oily skin.
Mineral Oil
Emollient & occlusive
A highly refined, cosmetic-grade oil that softens skin and slows water loss. It's lighter and more fluid than petrolatum, very rarely irritates, and is a staple of eczema and baby skincare.
Mineral Salts
Texture, stability & minerals
Simple mineral salts — such as magnesium sulfate (Epsom salt), potassium chloride and calcium chloride, or minerals bound to gluconic acid — used to adjust thickness, stabilise emulsions or supply skin-conditioning minerals. Inert in the small amounts used.
Niacinamide
Barrier support & even tone
Also known as Vitamin B3. Helps support the skin barrier, improve uneven tone, and reduce the appearance of pores. Usually well tolerated.
Nordihydroguaiaretic Acid
Antioxidant
An antioxidant originally isolated from the creosote bush, used in small amounts to help protect skin and the formula itself from oxidation.
Panthenol (Pro-Vitamin B5)
Soothing humectant
Pro-Vitamin B5. A humectant that hydrates, calms and supports the skin barrier, helping skin feel soft and comfortable. Gentle and suited to sensitive skin.
Pantolactone
Humectant
A small molecule closely related to panthenol (pro-vitamin B5): it is one of the building blocks used to make panthenol, and often appears alongside it on labels. On its own it works as a humectant, helping the skin hold on to water. It is not the same as panthenol and has far less research behind it, but it is considered gentle.
Parabens
Preservative
A family of preservatives that keep products free of bacteria and mould. They are among the most studied cosmetic preservatives: methylparaben and ethylparaben are considered safe at permitted levels, while the EU caps propyl- and butylparaben and bans several others. Allergy is uncommon, but some people choose paraben-free products.
PEG Stearates
Emulsifier & texture aid
PEG compounds help oil and water mix and give products a smooth feel. Considered safe in cosmetics; a small number of people with very sensitive skin prefer to avoid them.
Peptides
Signalling & firming
Short chains of amino acids that signal the skin to support collagen and firmness. A gentle anti-ageing option that suits most skin types.
Petrolatum
Occlusive moisturiser
A highly effective occlusive that seals the skin to prevent water loss. Cosmetic-grade petrolatum is purified, non-comedogenic and excellent for dry or compromised skin.
pH Adjusters (Hydroxides)
pH adjuster
Bases used in tiny amounts to fine-tune a formula's acidity so it is gentle on skin. Although strong on their own, they are fully neutralised in the finished product.
Phenoxyethanol
Preservative
A widely used preservative that protects products from bacteria and mould. Considered low-risk at the small concentrations permitted in cosmetics.
Plant Butters & Seed Oils
Rich plant emollients
Nourishing plant butters, seed oils and plant waxes (such as carnauba) that soften and protect the skin. Excellent for dry skin; the richest ones can occasionally feel heavy on oily or congestion-prone skin.
Plant Gums & Thickeners
Natural thickener
Thickeners from plants, seaweed or fermentation, such as acacia, guar, tara and gellan gum, that give gels and creams their body and keep them stable. Naturally derived and well tolerated.
Polysorbates
Emulsifier & solubiliser
Mild emulsifiers that help oils, fragrances and water mix evenly. Used in small amounts and considered low-risk.
Potassium Sorbate
Preservative
A mild, food-grade preservative that protects against yeast and mould. Commonly paired with other preservatives. Low irritation risk.
Propolis
Soothing & antioxidant
A resin bees collect from tree buds to protect their hives. It has antioxidant and antibacterial properties and is used to calm and nourish skin, especially in K-beauty. Generally gentle, but it can trigger reactions in people allergic to bee products, so patch test if that applies to you.
Propylene Glycol
Humectant & solvent
A humectant and carrier that helps ingredients penetrate and keeps formulas from drying out. Well tolerated by most, though a small number of people are sensitive to it.
Retinol
Cell turnover & anti-ageing
A form of Vitamin A that supports skin cell renewal, improving texture and tone. Can cause initial sensitivity — best introduced gradually.
Saccharide Isomerate
Long-lasting humectant
A sugar-derived humectant (sold as Pentavitin) that binds to the skin's surface and holds moisture there, so hydration lasts even after rinsing. Gentle and well tolerated.
Salicylic Acid
Exfoliant & pore clearer
A beta-hydroxy acid (BHA) that works inside the pore to remove dead skin cells and excess oil. Commonly used in acne-prone skincare.
Shea Butter
Rich emollient
A plant butter packed with fatty acids that deeply softens and nourishes skin. Ideal for dry skin; very occasionally too rich for those prone to congestion.
Silica
Texture & oil absorption
A mineral powder that absorbs excess oil and gives products a soft, smooth, blurring finish. Inert and well tolerated.
Snail Mucin
Hydrating & repairing
The filtered secretion of snails, rich in glycoproteins, hyaluronic acid and glycolic acid. It hydrates, helps skin look smoother and supports recovery from dryness and irritation — the reason it is a K-beauty favourite. Generally gentle, though it is animal-derived and some people find it slightly sticky.
Sodium Benzoate
Preservative
A gentle, widely used preservative that guards against bacteria and fungi. Often combined with potassium sorbate. Considered low-risk.
Sodium Chloride
Thickener & texture aid
Common salt, used in small amounts to thicken and stabilise certain formulas, especially cleansers. Inert at these levels.
Sodium PCA
Humectant (skin's own NMF)
A component of the skin's own natural moisturising factor. A lightweight humectant that helps skin hold water. Gentle and well tolerated.
Sodium RNA
Skin conditioning
The sodium salt of ribonucleic acid (RNA), usually sourced from yeast. It is used as a skin-conditioning ingredient, and brands include it to support the skin's natural renewal; independent evidence for that is limited. Considered non-irritating at the levels used in skincare.
Sorbitol
Humectant
A sugar alcohol that draws moisture into the skin and gives products a smooth feel. Mild and well tolerated.
Squalane
Lightweight emollient
A stable, lightweight oil that closely mimics the skin's natural sebum. Moisturises without feeling heavy or greasy. Well tolerated by most.
Starches
Oil absorption & mattifying
Plant starches such as corn (zea mays), rice and tapioca. They absorb excess oil, give a soft, powdery, matte finish and improve the feel of a formula. Gentle and well tolerated.
Stearic Acid
Fatty acid & emollient
A fatty acid that softens skin and helps give creams their thick, stable texture. A natural part of the skin's own lipids and generally very well tolerated.
Sucrose
Humectant
A sugar that acts as a natural humectant, helping skin hold onto water. Gentle and skin-friendly.
Sugars & Sugar Alcohols
Humectant
Simple sugars, sugar alcohols and short sugar chains that draw water to the skin's surface. Some, such as rhamnose and fructooligosaccharides, are also marketed as prebiotics that support the skin's natural microbiome. Gentle and well tolerated.
Sulfur
Blemish-clearing
A mineral long used for breakouts. It helps dry out spots, reduce excess oil and gently exfoliate, and has mild antibacterial properties. It can be drying and has a distinctive smell, so it is usually used as a targeted or short-contact treatment.
Sunflower Seed Oil / Extract
Emollient plant oil
A lightweight plant oil rich in linoleic acid and Vitamin E that softens skin and supports the barrier. Well tolerated, including by many with sensitive skin.
Synthetic Colours (CI Dyes)
Synthetic colourant
Synthetic dyes added purely for colour. Most people tolerate them well, but those with reactive or very sensitive skin sometimes prefer to avoid added colours.
Thiamidol
Dark-spot reducer
Eucerin's patented ingredient (INCI: Isobutylamido Thiazolyl Resorcinol) that inhibits tyrosinase, the enzyme behind pigment production, to fade the look of dark spots and prevent new ones. Generally well tolerated.
Titanium Dioxide
Mineral UV filter & colourant
A white mineral used as a gentle sunscreen filter, strongest against UVB, and as a white pigment (CI 77891) in makeup and tinted products. It sits on the skin's surface and suits sensitive skin. Often paired with zinc oxide, which covers more of the UVA range.
Trehalose
Humectant & protectant
A sugar-based humectant that hydrates and helps protect skin cells from moisture stress. Gentle and suited to all skin types.
Triacetin
Solvent & humectant
Glyceryl triacetate — glycerin combined with acetic acid. It dissolves other ingredients, keeps film-forming ingredients flexible and has mild humectant properties. Used in small amounts and generally well tolerated.
Triethyl Citrate
Solvent & texture aid
An ester of citric acid used to dissolve other ingredients, help formulas spread evenly and keep film-forming ingredients flexible. It also has mild deodorising properties, which is why it is common in deodorants. Used in small amounts in skincare and generally well tolerated.
Urea
Humectant & skin softener
A component of the skin's own natural moisturising factor. At low levels it hydrates; at higher levels it also helps soften rough, flaky skin. Well tolerated.
Vitamin B6 (Pyridoxine)
Skin conditioning
Vitamin B6, most often used in skincare as pyridoxine dipalmitate, an oil-soluble form. It is a skin-conditioning ingredient that helps keep skin feeling smooth, and some brands include it for oil balance. Gentle.
Vitamin C (Ascorbic Acid)
Antioxidant & brightening
A potent antioxidant that can help brighten skin, support collagen production, and protect against environmental damage. Can be unstable in some formulations.
Vitamin E (Tocopherol)
Antioxidant & conditioning
A skin-conditioning antioxidant that helps protect the skin barrier and defend against environmental damage. Tocopheryl acetate is its stable, common form.
Water (Aqua)
Solvent & base
The base of most skincare formulas. Dissolves water-soluble ingredients and forms the bulk of creams, gels and lotions. Usually the first ingredient listed.
Whey Protein
Conditioning protein
A milk-derived protein used to condition and soften skin. Generally well tolerated, though those with strong dairy sensitivities may wish to note it.
Xanthan Gum
Natural thickener
A plant-derived gum that thickens and stabilises formulas, giving them a pleasant gel-like consistency. Naturally derived and well tolerated.
Zinc Oxide
Mineral UV filter & skin protectant
A white mineral used as a broad-spectrum sunscreen filter, covering UVB and much of the UVA range. It is also the main ingredient in many nappy rash and barrier creams. Very well tolerated, including by sensitive skin; the main downside is a white cast.
Zinc PCA
Oil control & balancing
Zinc combined with PCA, a component of the skin's natural moisturising factor. The zinc helps regulate oil (sebum) and has mild antibacterial properties, while the PCA helps hold moisture — a combination often used for oily and breakout-prone skin.