If you follow a gluten-free diet — whether due to celiac disease, non-celiac gluten sensitivity, or personal choice — you probably already know to avoid bread, pasta, and baked goods made with wheat flour. But gluten is far more pervasive than most people realize. It hides in dozens of unexpected foods, beverages, medications, and everyday products, often under names that do not obviously indicate its presence.
Accidental gluten exposure is one of the most common reasons people on a gluten-free diet continue to experience symptoms. Even if you are diligent about avoiding obvious sources, these hidden sources of gluten could be undermining your health without your knowledge. Here are 15 surprising places where gluten may be hiding — and how to protect yourself.
1. Soy Sauce and Teriyaki Sauce
This is one of the most common hidden sources of gluten that catches people off guard. Traditional soy sauce is brewed with wheat as a primary ingredient. Since soy sauce is used as a base in many Asian-inspired dishes, marinades, and sauces, it can be a major source of hidden gluten exposure.
Safe alternative: Look for tamari (a Japanese soy sauce that is traditionally wheat-free) or coconut aminos. Always check the label, as some tamari brands do contain small amounts of wheat. The Gluten Safety app can help you quickly verify which brands are safe.
2. Salad Dressings and Marinades
Many commercial salad dressings use wheat flour or malt vinegar as a thickener or flavor enhancer. Balsamic vinegars, while naturally gluten-free, may be produced in facilities that also process wheat products. Marinades often contain soy sauce or beer, both of which typically contain gluten.
Safe alternative: Make your own dressings with olive oil, lemon juice, and herbs. When buying pre-made dressings, look for certified gluten-free labels and scan them with the Gluten Safety app for extra confidence.
3. Processed Meats and Deli Meats
Sausages, hot dogs, deli meats, meatballs, and meat patties often contain wheat-based fillers, breadcrumbs, or modified food starch derived from wheat. Some processing plants also use shared equipment with gluten-containing products, creating cross-contamination risks.
Safe alternative: Choose whole, unprocessed meats whenever possible. When buying processed meats, look for brands that specifically state they are gluten-free and check ingredients carefully.
4. Soups and Broths
Canned and restaurant soups are notorious hiding spots for gluten. Many cream-based soups use wheat flour as a thickening agent, and even clear broths may contain barley, wheat-based seasonings, or hydrolyzed wheat protein. Bouillon cubes frequently contain wheat starch or other gluten-containing ingredients.
Safe alternative: Make soup from scratch using fresh ingredients and gluten-free broth. If buying pre-made, select products labeled gluten-free and always verify with the Gluten Safety app from GlutenSafe.io.
5. Medications and Supplements
This is perhaps the most alarming hidden source of gluten. Many prescription and over-the-counter medications use wheat starch as a binding agent or filler in tablets and capsules. Vitamins and dietary supplements can also contain gluten-based ingredients. In the United States, pharmaceutical companies are not required to disclose the source of starch on their labels.
Safe alternative: Always ask your pharmacist about the gluten content of your medications. Websites like GlutenFreeDrugs.com maintain databases of safe medications. When choosing supplements, opt for brands that are certified gluten-free.
6. Beer and Malt Beverages
Most conventional beers are brewed with barley malt, which contains gluten. Even “light” beers are not safe for people with celiac disease. Malt beverages, flavored malt drinks, and some hard seltzers may also contain gluten.
Safe alternative: Look for beers brewed from gluten-free grains like sorghum, rice, or millet. Hard ciders, wine, and most distilled spirits (including vodka, gin, and rum) are generally considered safe, though some people with extreme sensitivity may react to grain-based spirits.
7. Flavored Coffee and Tea
Plain coffee and tea are naturally gluten-free, but flavored varieties can be a different story. Flavored coffees, coffee mixes, and specialty tea blends may contain barley malt, wheat-based flavorings, or other gluten-containing additives. Powdered coffee creamers and instant coffee mixes sometimes include wheat-derived ingredients as well.
Safe alternative: Stick to plain coffee and tea, and add your own gluten-free sweeteners and creamers. If you prefer flavored options, check labels carefully or use the gluten scanner app to scan products before purchasing.
8. Candy and Chocolate
While pure chocolate is naturally gluten-free, many candy bars and chocolate products contain wheat flour, barley malt, cookie pieces, pretzel inclusions, or wafer layers. Even chocolate that does not list wheat as an ingredient may be manufactured on shared equipment with gluten-containing candies.
Safe alternative: Choose dark chocolate bars with minimal ingredients and look for gluten-free certification. Many specialty candy brands now offer certified gluten-free options.
9. Oats and Oat Products
Oats do not naturally contain gluten, but conventional oats are almost always cross-contaminated with wheat, barley, or rye during growing, harvesting, and processing. Studies have shown that up to 88% of commercially available oat products contain measurable levels of gluten.
Safe alternative: Purchase only oats that are specifically labeled as “certified gluten-free.” These oats are grown in dedicated fields and processed in gluten-free facilities. Some individuals with celiac disease may still react to the protein avenin found in oats, so introduce them cautiously and under medical supervision.
10. French Fries and Fried Foods
Potatoes themselves are gluten-free, but french fries are one of the riskiest restaurant foods for people avoiding gluten. Many restaurants fry their french fries in the same oil as breaded items like chicken tenders, onion rings, and mozzarella sticks. Some frozen french fries are also coated with wheat flour to make them crispier. Additionally, seasoned fries may contain wheat-based seasoning blends.
Safe alternative: Ask restaurants if they have a dedicated fryer for french fries. At home, make your own fries with fresh potatoes and a clean fryer or oven. Check frozen fry labels carefully for wheat-based coatings — the Gluten Safety app makes this quick and easy.
11. Lip Balm, Lipstick, and Personal Care Products
While gluten cannot be absorbed through the skin, products applied to or near the mouth can be inadvertently ingested. Lip balms, lipsticks, and even some toothpastes may contain wheat germ oil, barley extract, oat extract, or vitamin E derived from wheat. Over the course of a day, small amounts of these products can accumulate.
Safe alternative: Choose personal care products from brands that specifically formulate gluten-free products. Pay particular attention to any product that may come into contact with your mouth.
12. Communion Wafers and Playdough
Traditional communion wafers are made from wheat flour, and many churches require them for the sacrament. This is a significant concern for people with celiac disease who participate in religious services. Similarly, children’s playdough — including the popular Play-Doh brand — is made with wheat flour and can cause issues for children with celiac disease who touch it and then put their hands in their mouths.
Safe alternative: Many churches now offer gluten-free communion wafers. For playdough, make a homemade version using rice flour or purchase a gluten-free alternative.
13. Spice Blends and Seasoning Mixes
Individual spices are naturally gluten-free, but pre-mixed spice blends and seasoning packets often contain wheat flour, wheat starch, or malt dextrin as anti-caking agents or fillers. Popular seasoning mixes for tacos, chili, and grilled meats are common culprits.
Safe alternative: Mix your own spice blends from individual spices, or look for brands that certify their blends as gluten-free. Use the Gluten Safety app to quickly check food for gluten at the store.
14. Imitation Crab and Seafood
Imitation crab meat (surimi), commonly found in sushi rolls, seafood salads, and crab cakes, almost always contains wheat starch as a binding ingredient. It is made from processed white fish that is shaped and flavored to resemble crab, and wheat is a standard component of the formulation.
Safe alternative: Use real crab meat or other fresh seafood instead. If you enjoy sushi, ask for rolls made with real crab and confirm that other ingredients (like soy sauce and tempura flakes) are gluten-free as well.
15. Gravy and Cream Sauces
Traditional gravy is made by whisking wheat flour into meat drippings, making it a significant source of gluten. Similarly, many cream sauces, béchamel, and roux-based sauces rely on wheat flour as their primary thickening agent. Restaurant gravies and sauces are almost always made with wheat flour unless specifically noted otherwise.
Safe alternative: Thicken gravies and sauces with cornstarch, arrowroot, or tapioca starch instead of wheat flour. Many gluten-free cookbooks offer excellent recipes for classic sauces made without gluten.
How to Protect Yourself from Hidden Gluten
The sheer number of hidden gluten sources can feel overwhelming, but there are practical steps you can take to minimize your risk:
- Always read ingredient labels. Do not assume a product is safe because it was safe last time — manufacturers change formulations regularly.
- Look for certification. Products certified gluten-free by organizations like the Gluten-Free Certification Organization (GFCO) have been tested to contain less than 10 ppm of gluten.
- Use technology to your advantage. The free Gluten Safety app from GlutenSafe.io allows you to scan barcodes and search for products instantly, taking the guesswork out of gluten-free grocery shopping.
- When in doubt, leave it out. If you cannot verify that a product is gluten-free, do not eat it. Your health is not worth the risk.
- Educate those around you. Help family members, friends, and coworkers understand the seriousness of gluten contamination so they can support you in staying safe.
Conclusion
Gluten hides in far more places than most people expect. From soy sauce and salad dressings to medications and lip balm, the potential sources of accidental exposure are numerous. But knowledge is power — by familiarizing yourself with these hidden sources of gluten and adopting a proactive approach to label reading and product verification, you can dramatically reduce your risk of accidental gluten exposure.
Make the Gluten Safety app your constant shopping and dining companion. With its powerful gluten scanning technology and comprehensive database, it helps you identify hidden gluten quickly and confidently — so you can focus on enjoying your food, not worrying about it. Download it for free today from your app store and take control of your gluten-free journey.