Ingredient guides

Plain-English breakdowns of common skincare and product ingredients. What they do, who reacts to them, and the names they hide behind on labels.

preservative

Benzyl Alcohol: A Dual-Role Preservative and Declared Fragrance Allergen

Benzyl alcohol preserves products, carries scent and is one of the 26 EU-declared fragrance allergens. Here's what it is, who reacts, and where to spot it.

fragrance

Cinnamal: The Warm Spice Note That's a Declared Allergen

Cinnamal gives products a warm cinnamon scent and is one of the 26 EU-declared fragrance allergens. What it is, why it is named on labels, who reacts, and where it hides.

surfactant

Cocamidopropyl Betaine: The 'Gentle' Cleanser That Can Still Irritate

Cocamidopropyl betaine is a mild, coconut-derived surfactant in gentle and baby cleansers, but it is still a recognised contact allergen. The balanced picture, who reacts, and where it hides, in plain UK English.

fragrance

Coumarin: The Sweet, Hay-Like Fragrance Allergen on Your Label

Coumarin gives products a warm, sweet, new-mown-hay scent and is one of the named EU and UK fragrance allergens. Here is what it is, who reacts, and where to spot it.

essential-oil

Essential Oils in Skincare: Why Natural Does Not Mean Non-Allergenic

Essential oils are plant-derived and popular, but they are among the more common causes of skin allergy. A plain-English, UK-focused guide to what they are, who reacts, and how to spot them on a label.

fragrance

Eugenol: The Clove-Scented Fragrance Allergen on Your Label

Eugenol gives products a warm, clove-like note and is one of the named EU fragrance allergens. What it is, the UK and EU rules, who reacts, and where to spot it, in plain UK English.

preservative

Formaldehyde-Releasing Preservatives: The Hidden Allergen Group

Several common preservatives slowly release small amounts of formaldehyde, a recognised contact allergen. What they are, the names they hide under, the UK and EU rules, and how to spot the whole group.

fragrance

Geraniol: A Rose-Scented Declared Fragrance Allergen

Geraniol gives products a sweet, rosy note and is one of the 26 declared fragrance allergens in UK and EU law. A plain-English guide to what it is, who reacts, and where to spot it.

emollient

Lanolin: The Wool-Derived Moisturiser That Some Skin Reacts To

Lanolin is a natural emollient from sheep's wool, brilliant for very dry skin but a recognised allergen for some. What it is, who reacts, the names it hides under, and the nursing-parent angle, in plain UK English.

fragrance

Limonene: The Citrus Scent That's a Declared Fragrance Allergen

Limonene gives products a fresh citrus note and is one of the named EU fragrance allergens. What it is, why it is spelled out on labels, who reacts, and the oxidation catch, in plain UK English.

fragrance

Linalool: The Floral Fragrance Allergen Found Almost Everywhere

Linalool is a floral scent compound and one of the 26 declared fragrance allergens in UK and EU law. A plain-English guide to what it is, why it oxidises, and who tends to react.

preservative

Methylisothiazolinone (MI): The Preservative Behind Many Reactions

Methylisothiazolinone (MI) is a common preservative and one of the leading causes of contact allergy in the UK and EU. A plain-English guide to what it is, where it hides, and who tends to react.

preservative

Parabens: What They Are and the Honest Take on the Controversy

Parabens are widely used preservatives that became a flashpoint in clean beauty. A plain-English UK guide to what they do, who actually reacts, and a balanced view of the concerns.

preservative

Phenoxyethanol: The Common Preservative Behind Some Sensitive-Skin Reactions

Phenoxyethanol keeps water-based products from spoiling and is one of the most widely used cosmetic preservatives. Here's what it is, who reacts, and where to spot it.

other

Propylene Glycol: The Workhorse Humectant, and When It Bothers Skin

Propylene glycol helps skincare hold moisture and carry active ingredients. A plain-English UK guide to what it does, irritation versus true allergy, and who should keep an eye on it.

surfactant

Sodium Lauryl Sulphate (SLS): What It Does and Who Should Watch It

Sodium lauryl sulphate (SLS) is the foaming agent in many cleansers. A plain-English UK guide to what it does, how it differs from SLES, and why sensitive skin sometimes reacts.

fragrance

What 'Fragrance' Actually Means on a Label

On an ingredient label, the word 'fragrance' can hide dozens of undisclosed chemicals. Here's what it really means, who reacts to it, and how to spot it.

Food additives and ingredients

The colours, preservatives and other additives on food labels that can trigger skin reactions, hives, itching and eczema flares, rather than digestion.

Food
colour

Allura Red (E129): The Red Azo Dye Linked to Hives and Itching

Allura Red (E129) is a synthetic red azo dye in sweets, drinks and snacks, and one of the colours linked to hives and flushing in sensitive people. What it is, who reacts, and how to spot it.

Food
natural

Annatto (E160b): The Natural Colour That Can Still Trigger Skin

Annatto (E160b) is a plant-derived yellow-orange food colour in cheese, butter and snacks, and a recognised, if uncommon, trigger of hives in sensitive people. What it is, where it hides on UK labels, and calm steps if you suspect it affects your skin.

Food
additive - antioxidant preservative

BHA and BHT (E320, E321): Antioxidant Preservatives and the Skin

BHA (E320) and BHT (E321) are antioxidant preservatives that keep fatty foods from going rancid, and they turn up in cosmetics too. A plain-English UK guide to what they are, who reacts, and how to spot them on a label.

Food
colour

Brilliant Blue (E133): The Synthetic Blue Dye and the Skin

Brilliant Blue (E133) is a synthetic blue colour in drinks, sweets and even mouthwash. Reactions are less common than with azo dyes, but they happen. What it is, where it hides on UK labels, and calm steps if you suspect a reaction.

Food
preservative

Calcium Propionate (E282): The Bread Preservative and Sensitive Skin

Calcium propionate keeps bread mould-free and is one of the additives some people link to hives and eczema flares. What it is, who reacts, and where it hides.

Food
additive - natural colour

Carmine and Cochineal (E120): A Natural Red That Still Reacts

Carmine (E120) is a natural red colour made from insects, and natural does not mean inert. A UK plain-English guide to what it is, who reacts, where it hides, and how to spot it on a label.

Food
colour

Carmoisine (E122): The Red Azo Dye in the Southampton Six

Carmoisine (E122), also called azorubine, is a synthetic red azo dye linked to hives and itching in sensitive people. What it is, who reacts, and how to spot it.

Food
condition - chronic urticaria

Chronic Hives and Food: Which Triggers Are Worth Checking

When hives keep coming back, food is a common suspect. A calm, UK-anchored guide to the additives and natural foods most often linked to chronic urticaria, and a sensible way to find your own triggers.

Food
colour

Erythrosine (E127): The Tightly Restricted Cherry-Red Dye

Erythrosine (E127) is a synthetic red dye now limited to cocktail and candied cherries in the UK and EU. What it is, who reacts on the skin, and where it still hides.

Food
additive

Monosodium Glutamate (MSG): What the Skin Evidence Actually Says

MSG (E621) is a flavour enhancer often blamed for reactions. For skin symptoms the honest evidence is weak and mixed. What it is, what the science shows, and how to test it for yourself.

Food
additive

Patent Blue V (E131): The Synthetic Blue Dye and the Skin

Patent Blue V (E131) is a synthetic blue colour in sweets, drinks and some medicines. Food reactions are uncommon, but they happen in sensitive people. What it is, who reacts, and where it hides.

Food
colour

Ponceau 4R (E124): The Red Azo Dye and the Skin

Ponceau 4R (E124) is a synthetic red azo dye in sweets, drinks and desserts that can trigger hives in people sensitive to azo colours. What it is, the UK children's warning it must carry, where it hides on labels, and calm steps if you suspect a reaction.

Food
preservative

Potassium Sorbate (E202): A Common Preservative and the Skin

Potassium sorbate keeps countless foods and cosmetics fresh, and is an occasional cause of contact reactions and hives. What it is, who reacts, and where it hides.

Food
colour

Quinoline Yellow (E104): A Southampton Colour and the Skin

Quinoline Yellow (E104) is a bright yellow food colour, one of the 'Southampton Six', that some people with chronic hives find worsens their skin. What it is, who reacts, and where it hides.

Food
preservative

Sodium Benzoate and the Benzoates (E210 to E213): Preservatives and Chronic Hives

Benzoate preservatives like sodium benzoate (E211) keep soft drinks, sauces and pickles fresh, and are repeatedly linked to worsening chronic hives in sensitive people. What they are, where they hide on UK labels, and calm steps if you suspect a reaction.

Food
preservative

Sodium Nitrite and the Nitrites (E249 to E252): Cured Meats and Flushing

Nitrite and nitrate preservatives in bacon, ham and salami are linked to flushing and headache, and often pile onto the histamine load that drives hives. What they are, where they hide on UK labels, and calm steps if you suspect a reaction.

Food
additive

Sulphites (E220 to E228): Wine, Dried Fruit and the Skin

Preservatives in wine, dried fruit and processed foods that can trigger flushing, hives and itching.

Food
additive

Sunset Yellow (E110): The Orange Dye Linked to Hives

Sunset Yellow (E110) is a synthetic orange azo dye in drinks and sweets, and one of the colours linked to hives and itching in sensitive people. What it is, who reacts, and how to spot it.

Food
additive - synthetic colour (azo dye)

Tartrazine and Other Azo Dyes: The Food Colours Linked to Hives

Azo dyes like tartrazine (E102) are bright synthetic food colours that can trigger hives and itching in sensitive people. A UK plain-English guide to what they are, who reacts, the label rules, and how to spot them.