How to read food labels for allergens: a step-by-step guide

To read a food label for allergens, check three places every time: the ingredient list, any allergen names in parentheses, and the “Contains” statement, then look for voluntary “may contain” warnings. In the US, the law requires the food source of each major allergen to appear at least once, either inside the ingredient list (for example, “whey (milk)”) or in a “Contains” statement placed next to or after it, according to the FDA.

1. Read the whole ingredient list, slowly, from start to finish.
2. Look for allergen names in parentheses after less obvious ingredients, such as “albumin (egg)”.
3. Read the “Contains” statement if there is one, but do not stop there.
4. Look for “may contain” or “made in a facility” wording, and decide with your allergist how to treat it.
5. If anything is unclear, put the product back or contact the manufacturer listed on the pack.

An FDA food technologist quoted in the agency’s consumer update Have Food Allergies? Read the Label puts it simply: if you see your allergen’s name even once, the product goes back on the shelf.

The Food Allergen Labeling and Consumer Protection Act (FALCPA) and the FASTER Act cover nine major allergens: milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame. For a full overview of the list, see our guide to the major food allergens.

• Specific names for some groups. Tree nuts, fish and crustacean shellfish must name the type, such as almond, tuna or crab.
• Small amounts count. FARE notes that manufacturers must list a major allergen even in very small amounts.
• Sesame is newer. Sesame labeling has been required since January 1, 2023. Products made earlier may not list it, so the FDA suggests checking with the manufacturer.
• Milk and eggs from other animals. Since 2025 the FDA treats milk from goats, sheep and other ruminants, and eggs from ducks, quail and other fowl, as major allergens, and recommends naming the animal, such as “goat milk” or “duck egg”.

Some foods sit outside these rules. The FDA enforces FALCPA on the foods it regulates; most meat, poultry, certain egg products and most alcoholic drinks are overseen by other federal agencies. FARE adds that fresh foods such as meat, fruit and vegetables do not carry this labeling. For unpackaged foods like bakery items, the FDA advises asking store staff for allergen information.

A “Contains” statement is useful, but it is optional. The FDA notes that not every product with an allergen carries one, because the manufacturer may instead put the allergen name in parentheses within the ingredient list. If you only scan for the “Contains” line, you can miss it.

It also only covers the US top 9. If you react to something else, such as mustard, celery or a mollusc, nothing on a US label is required to flag it. FARE warns that allergens outside the law can be hidden under general terms like “natural flavorings” or spices, and that molluscan shellfish such as oysters, clams and scallops do not have to be labeled as a major allergen.

Manufacturers are usually the best people to answer questions a label cannot. The FDA suggests contacting the manufacturer or distributor named on the pack if you are unsure whether a product contains an ingredient you react to, and not buying it until you know. FARE suggests asking about manufacturing practices as well as ingredients, since shared equipment is not something the ingredient list will show.

Many ingredients come from an allergen without its name in them. The FDA gives the example of casein, sodium caseinate and whey: all milk proteins. US law means “milk” must still appear on the label at least once, but learning the common aliases helps you read faster and spot problems in products from places with different rules.

These examples come from the FDA and the Allergy & Asthma Network. When one of these names appears, check whether the label also names your allergen, and ask the manufacturer if it does not. This table is a starting point, not a complete list. Ask your allergist or a registered dietitian for a fuller list for your allergen. If you avoid milk, our guide to lactose-free vs dairy-free explains how those two claims differ.

Phrases such as “may contain” or “produced in a facility that also uses” are called precautionary or advisory labels. In the US they are voluntary. The FDA says they should only be used for unavoidable cross-contact, cannot replace good manufacturing practices, and must be truthful and not misleading.

• A “may contain” label means there may be a risk of cross-contact. It does not tell you how much, or how likely.
• No warning does not mean no risk. Some manufacturers simply do not use these labels.
• Claims like “peanut-free” or “egg-free” are not regulated in the same way, FARE notes, so a product may still be made where allergens are present.
• The FDA says a product should not claim to be free of an allergen while also warning it may contain it.

How to treat “may contain” is a personal decision that depends on your allergy and its severity. Talk it through with your allergist, and when in doubt, contact the manufacturer and ask how they handle your allergen on that line.

If you travel or shop for imported European foods, the rules look different. Under Regulation (EU) No 1169/2011, the 14 allergens must be emphasized within the ingredient list using a typeset that clearly sets them apart, for example by font, style or background color. In practice you will usually see them in bold, so there is often no separate “Contains” line.

• Look for highlighted words inside the ingredient list rather than a statement below it.
• The EU and UK list covers 14 allergens, including celery, mustard, lupin, molluscs and sulphites, which are not on the US list.
• In the UK, food that is prepacked for direct sale, such as a boxed sandwich made on site, must show an ingredient list with the 14 allergens emphasized, per GOV.UK.
• Restaurants and takeaways in the UK must be able to tell you about the 14 allergens in their food. If you are allergic to something outside the 14, GOV.UK says you can ask the business whether its food contains it.

Labeling rules vary by country, and FARE advises taking extra care with imported foods. An allergen list from another country may cover different foods, use different words, or appear only in another language.

• Do not buy a product that has no ingredient list, or one you cannot read.
• Learn how your allergen is written in the language of countries you buy from or visit.
• When you travel, our guide to traveling with food allergies and intolerances covers labels abroad.

If you have a reaction or find a label that seems wrong, the FDA suggests keeping the packaging, talking with your health care provider and considering contacting the manufacturer. You can also report it to the FDA with product details such as lot codes and photos.

• Read every time. FARE and the FDA both stress that ingredients and manufacturing can change, even for foods you have eaten before.
• Check sub-ingredients. A sauce, seasoning or filling can bring an allergen into an otherwise simple food. Our guides to hidden gluten and hidden garlic and onion show how this works for intolerances too.
• Teach children early. FARE suggests children can start checking labels once they can read, with an adult’s help.
• Keep a note of products you have checked. A food and symptom diary helps, but still re-read the label each time.

Label reading is a skill, and it gets quicker with practice. Your allergist can help you decide how strict to be with precautionary labels and which aliases matter most for you.