Skincare Ingredient Glossary
What's actually in your skincare — explained in plain English, without the fear-mongering.
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.
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.
Amino Acids
Hydration & barrier support
Building blocks of proteins that hydrate skin and support its natural moisturising factor and barrier. 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.
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.
Cucumber Extract
Soothing botanical
A water-rich botanical traditionally used to refresh and calm the skin. Light and gentle, with a mild soothing effect.
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.
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.
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.
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.
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 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.
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.
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.
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.
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.
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.
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.
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.
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 waxes that soften and protect the skin. Excellent for dry skin; the richest ones can occasionally feel heavy on oily or congestion-prone skin.
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.
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.
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.
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.
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.
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.
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.
Titanium Dioxide
Mineral UV filter & colourant
Minerals (titanium dioxide and zinc oxide) that reflect and scatter UV light, used as gentle sunscreen filters and white pigments. Sit on the skin's surface and are well suited to sensitive skin.
Trehalose
Humectant & protectant
A sugar-based humectant that hydrates and helps protect skin cells from moisture stress. Gentle and suited to all skin types.
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 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.