Xanthan gum is one of the most common thickeners in gluten-free baking, yet it is also one of the most-Googled ingredients by people avoiding gluten — because it can, in fact, be made from wheat. The good news is that US allergen labeling law makes the answer readable directly from the ingredient list, without any guesswork.
What xanthan gum is made from
Xanthan gum is a fermented carbohydrate produced by the bacterium *Xanthomonas campestris*. The fermentation substrate — the sugar source the bacteria feed on — can be corn, wheat, soy, or dairy. The substrate does not end up in the finished gum (it is consumed in fermentation), but it can leave traces of its source protein behind, which matters for people with allergies or celiac disease.
How to tell from the label
Under the Food Allergen Labeling and Consumer Protection Act (FALCPA), if xanthan gum is derived from wheat, the label must declare wheat — either in the ingredient name itself ('xanthan gum (wheat)') or in a 'Contains: wheat' statement immediately after the ingredient list (FDA). If the label says only 'xanthan gum' with no wheat anywhere in the allergen declaration, the manufacturer is legally required to be using a non-wheat substrate. For most celiac and wheat-allergy needs, a label showing 'xanthan gum' alone (no wheat declaration) is sufficient. However, if a product also carries a 'gluten-free' claim, the FDA gluten-free labeling rule (21 CFR 101.91) additionally requires that the product contains less than 20 ppm gluten — so a 'gluten-free' label adds a second layer of protection beyond the ingredient declaration alone.
Corn-derived and soy-derived xanthan gum
Most xanthan gum sold in the US today is corn-derived, which is gluten-free. Some is soy-derived — which is gluten-free but not soy-free. The same FALCPA rule applies: if soy-derived, the label must declare soy. If you react to corn or soy specifically, the label declaration gives you the signal, even though neither corn nor soy is a wheat/gluten issue.
Hidden Allergen Names Decoder
Paste any ingredient list to highlight allergen names
Open Hidden Allergen Names Decoder →Read the ingredient list and the 'Contains:' statement. 'Xanthan gum' with no wheat anywhere = not wheat-derived, per US law. 'Gluten-free' on the front adds a 20 ppm limit on top.