If you have gluten intolerance, you need to avoid wheat, barley, rye, and triticale (a rye-wheat hybrid), along with dozens of processed foods, beverages, and even some medications that contain hidden gluten. The obvious sources like bread and pasta are easy to spot. It’s the less obvious ones that trip people up.
The Core Grains to Eliminate
Gluten is a protein found in four grains: wheat, barley, rye, and triticale. Wheat goes by many names on ingredient labels, and all of them contain gluten. Durum, semolina, spelt, farro, einkorn, kamut, and bulgur are all types of wheat. Sprouted wheat bread, including popular brands like Ezekiel bread, still contains gluten despite being marketed as a health food.
Any flour, bran, or germ derived from these grains contains gluten. That includes wheat flour in all its forms: all-purpose, bread flour, cake flour, whole wheat flour, and graham flour. Barley shows up frequently as malt, malt extract, malt flavoring, and malt vinegar. If you see “malt” on a label without a gluten-free certification, assume it comes from barley.
Processed Foods With Hidden Gluten
Gluten hides in processed foods where you’d never expect it. It works well as a thickener, stabilizer, and binder, so manufacturers add it to products that seem like they should be naturally gluten-free. Here are the biggest offenders:
- Deli and processed meats: Cold cuts, hot dogs, salami, sausage, and self-basting poultry often contain gluten as a filler or binder.
- Sauces and condiments: Soy sauce is made with wheat (tamari is the gluten-free alternative). Salad dressings, gravies, and bouillon cubes frequently use gluten as a thickener.
- Soups: Chowders, chilis, and cream-based soups often rely on wheat flour for body.
- Seasoned snacks: Potato chip seasonings can contain malt vinegar and wheat starch.
- Flavored drinks: Some flavored coffees and teas contain gluten.
- Candy and bars: Licorice, energy bars, and granola bars are common sources.
- Ice cream: Flavored varieties like cookie dough or cookies-and-cream contain gluten. Even some plain flavors use gluten-based stabilizers.
- Meat substitutes: Veggie burgers, imitation bacon, plant-based crumbles, imitation seafood, and seitan (which is literally made of pure gluten) all pose risks.
- Miso: Some varieties are made with barley rather than rice.
Tricky Ingredients on Labels
If a product isn’t labeled “gluten-free,” scan the ingredients list carefully. Several common additives can be derived from gluten-containing grains: modified food starch, hydrolyzed vegetable protein, hydrolyzed plant protein, textured vegetable protein, dextrin, maltodextrin, glucose syrup, caramel color, and brown rice syrup. These don’t always contain gluten, but unless the label specifies the source or carries a gluten-free certification, you can’t be sure.
The FDA defines “gluten-free” as containing less than 20 parts per million of gluten. That’s the threshold manufacturers must meet to use the label. Products that don’t carry this label have no obligation to disclose gluten content beyond listing wheat as an allergen.
The Oats Question
Oats don’t naturally contain gluten, but conventional oats are heavily cross-contaminated during growing, harvesting, and processing alongside wheat and barley. Standard oats from the grocery store are not safe for people with gluten intolerance. Only oats produced under a “purity protocol,” meaning strict controls from farm through packaging, reliably meet the less-than-20-ppm gluten-free standard. Look for oats specifically labeled “gluten-free” or “purity protocol.”
A small percentage of people with celiac disease also react to avenin, a protein in oats that’s structurally similar to gluten. If you still have symptoms after switching to certified gluten-free oats, oats themselves may be the problem.
Alcohol That Contains Gluten
Beer, ale, lager, and malt beverages are made from barley or wheat and contain gluten. This includes most craft beers. “Gluten-removed” beers, which are brewed with gluten-containing grains and then treated to reduce gluten levels, are not considered safe. Reliable testing methods can’t accurately measure residual gluten in fermented products, so the actual gluten content is uncertain. Beer labeled “gluten-free” that’s brewed from naturally gluten-free grains like sorghum or rice is a safer choice.
Wine is naturally gluten-free. Distilled spirits, even those made from wheat, rye, or barley (like most whiskeys and some vodkas), are generally safe because distillation removes gluten proteins. The exception is flavored spirits. Flavorings are added after distillation and can reintroduce gluten, so check labels on flavored vodkas, whiskeys, and liqueurs.
Medications and Supplements
Prescription and over-the-counter medications can contain gluten in their inactive ingredients. Starch is one of the most common fillers in pills and tablets, used as a binder, coating, or disintegrant. Pregelatinized starch and sodium carboxymethyl starch are the most frequently used forms, and they can be derived from wheat. A 2025 analysis of pharmaceutical products found these wheat-derived starches across multiple drug categories.
The problem is that medication labels aren’t required to specify the grain source of starch-based ingredients. If an ingredient list simply says “starch” or “modified starch” without naming the source, you can’t tell whether it’s corn-based (safe) or wheat-based. Your pharmacist can contact the manufacturer to confirm, and some pharmaceutical companies maintain gluten-free product lists on their websites. Don’t stop taking prescribed medications without talking to your pharmacist about alternatives first.
Lip Products and Cosmetics
Gluten in skin care products like body lotion isn’t a concern for most people with gluten intolerance, since gluten must be ingested to cause a reaction. The exception is anything that goes on or near your mouth. Lipstick, lip balm, lip gloss, and even some toothpastes can contain gluten-derived ingredients that you might accidentally swallow.
Watch for these ingredients in lip products: hydrolyzed wheat protein, triticum vulgare (wheat germ oil), hordeum vulgare extract (barley), secale cereale (rye), malt extract, and dextrin palmitate. Some of these use Latin names that aren’t immediately recognizable. If you’re unsure, look for brands that specifically market their lip products as gluten-free.
Cross-Contact in the Kitchen
Even if every ingredient in your meal is gluten-free, cross-contact during preparation can introduce enough gluten to cause symptoms. Shared toasters are one of the most common culprits. Crumbs from regular bread accumulate inside and transfer to gluten-free bread. The same applies to shared cutting boards, colanders, and wooden utensils, which can trap gluten in scratches and pores.
Deep fryers pose a significant risk. Gluten-free foods cooked in the same oil as breaded items pick up gluten from the oil and from shared baskets and holding trays. This is a particular concern at restaurants, where fries, onion rings, and breaded chicken often share the same fryer. If a restaurant can’t confirm a dedicated fryer, assume the fried food contains gluten.
At home, keeping a separate set of tools for gluten-free cooking is the most reliable approach. Dedicated toasters, cutting boards, and colanders eliminate the guesswork. Shared pots and pans are fine as long as they’re thoroughly washed between uses, since smooth surfaces don’t harbor gluten the way porous materials do.
Gluten Intolerance vs. Celiac Disease
How strictly you need to avoid gluten depends partly on your specific condition. Celiac disease is an autoimmune disorder where even trace amounts of gluten trigger an immune response that damages the lining of the small intestine. People with celiac disease need to stay below the 20-ppm threshold consistently, because intestinal damage occurs whether or not symptoms are noticeable.
Non-celiac gluten sensitivity (NCGS) causes similar symptoms, including bloating, fatigue, headaches, and digestive discomfort, but doesn’t produce the same intestinal damage or autoimmune markers. Some people with NCGS find they can tolerate small amounts of gluten without symptoms, while others are just as sensitive as those with celiac disease. Interestingly, research suggests that some people diagnosed with NCGS may actually be reacting to FODMAPs, a group of fermentable carbohydrates found in wheat and many other foods, rather than gluten itself. If a strict gluten-free diet doesn’t fully resolve your symptoms, a low-FODMAP trial with a dietitian may help clarify what’s actually triggering them.