Scan the back of almost any serum, cream or cleanser in your bathroom cabinet and you will find it lurking near the bottom of the INCI list: xanthan gum. It sounds like an industrial additive, but it is one of the most benign, well-studied and genuinely useful ingredients in modern formulation — a quiet workhorse that makes the products you already love feel the way they do.
Here is what xanthan gum actually is, what it does for your skin, and which REFORM Skincare products in the UK range are built with it.
What Is Xanthan Gum?
Xanthan gum is a polysaccharide — a long chain of sugar molecules — produced by fermenting glucose or sucrose with a bacterium called Xanthomonas campestris. The same fermentation process that gives us yoghurt and miso gives us this: the bacteria secrete a thick, goo-like substance, which is then purified, dried and milled into a fine powder.
It was discovered in the 1950s by USDA researchers looking for a cheap, reliable thickener, and it has since become one of the most widely used gums in the world — you will find it in gluten-free baking, salad dressings, ice cream and, of course, cosmetics. The Cosmetic Ingredient Review has recorded thousands of uses in cosmetic formulations, making it one of the most widely used microbial polysaccharides in beauty.
In skincare, xanthan gum is classified by its INCI function as a binding agent, emulsion stabiliser, gel former, viscosity controller and skin-conditioning agent. In plain terms: it thickens water-based formulas, holds oil and water together so they do not separate, and keeps everything evenly dispersed.
Its standout property is shear-thinning behaviour. At rest, xanthan gum forms a flexible, gel-like network that keeps a formula thick and stable; when you rub it into your skin, that network loosens and the product flows easily. It is why a serum slides out of the dropper rather than dripping, and why a cream spreads smoothly instead of sitting in a greasy blob.
The Skin Benefits of Xanthan Gum
Xanthan gum is not an "active" in the way retinol or vitamin C is — it will not resurface your skin or fade pigmentation on its own. Its benefits are structural, but that does not make them trivial.
It stabilises and protects the formula. Xanthan gum keeps oil-in-water emulsions from splitting, and it remains stable across a broad temperature and pH range. Practically, that means your moisturiser is the same consistency on the first day and the last, and that water-soluble and oil-soluble actives stay properly blended rather than separating out.
It delivers actives evenly. Because xanthan gum suspends insoluble particles and holds a formula homogeneous, the active ingredients in a product reach your skin in a uniform way rather than pooling in one area of the tube.
It improves texture and spreadability. A well-thickened gel or cream is easier to dose, easier to spread and feels more comfortable on the skin. Xanthan gum is often used alongside other thickeners such as hydroxyethylcellulose because the combination gives a better finish than either alone.
It supports hydration. Xanthan gum is a humectant-adjacent ingredient: it helps form a light film on the skin's surface that reduces moisture loss, and it gives hydrating formulas a substance that holds water against the skin rather than evaporating immediately.
It is exceptionally well tolerated. This is the big one. Xanthan gum carries the lowest possible hazard rating from the EWG (1), with no significant concerns for irritation, sensitisation, comedogenicity or toxicity at typical use concentrations. It is non-irritating and non-sensitising, and is regarded as suitable even for sensitive, atopic and baby skin. A 2016 review by the Cosmetic Ingredient Review reconfirmed its safety in cosmetics.
It is naturally derived and biodegradable. For anyone building a routine around plant-forward, clean-label formulas, xanthan gum is a fermentation-derived thickener rather than a synthetic polymer — and it breaks down in the environment.
One caveat worth knowing: because it is a sugar-based polysaccharide, xanthan gum is sometimes confused with skincare "gums" that can feel tacky or pill under makeup. At the low concentrations used in cosmetics — typically 0.1–2%, higher only in dedicated gels — this is rarely an issue. It appears near the end of ingredient lists precisely because so little is needed.
REFORM Skincare Products Containing Xanthan Gum
REFORM Skincare's UK range lists xanthan gum openly on its full ingredient breakdowns, described honestly as a thickener and stabiliser rather than dressed up as an active. Here are the products that contain it.
Gentle Hydrating Crème Cleanser
A dermatology-recommended crème cleanser for dry, sensitive and rosacea-prone skin, built around Sweet Almond Oil, Niacinamide and Vitamin E. Xanthan gum is listed as the natural thickening and stabilising agent that gives the cream its texture and consistency, so it cleanses without stripping.
Intensive Moisturiser
An active hydration and barrier repair cream formulated with niacinamide. Xanthan gum appears in the texture-enhancing group alongside ammonium acryloyldimethyltaurate/VP copolymer, giving the cream its smooth gel-cream feel and keeping the emulsion stable.
Skin Barrier Repair Cream
A rich, non-greasy emollient cream for very dry, rough, flaky and compromised skin, formulated with Urea, Lactic Acid, Vitamin E, Olus Oil and 2% Pro-Vitamin B5. Xanthan gum acts as the thickener, improving consistency and holding the emollient blend together.
Glycolic Acid Foaming Cleanser / Glycolic Acid Wash
REFORM's exfoliating wash, formulated with mandelic and glycolic acids alongside allantoin, resveratrol and bisabolol. Xanthan gum appears in the ingredient list as part of the viscosity-controlling system that gives the cleanser its body.
A practical note: REFORM reformulates and extends its range over time, and formulas do occasionally change. If you are checking for a specific ingredient — whether xanthan gum or anything else — the full ingredient breakdown on each individual product page is the authoritative source, and it is worth a final glance before you buy.
The Bottom Line
Xanthan gum is the invisible ingredient doing a lot of unglamorous work in your skincare. It thickens, stabilises, suspends and smooths, and it does so with one of the cleanest safety profiles in cosmetic chemistry — no irritation risk, no comedogenic concern, and a naturally derived origin.
It will not transform your skin on its own, and it is not meant to. What it does is make sure the ingredients that do transform your skin — your niacinamide, your panthenol, your glycolic acid — arrive on your face evenly, comfortably and at full strength, every single time.
