How to Check for Allergens and Inactive Ingredients on Prescription and Food Labels

Reading a food or medicine label might seem like a quick glance-but for people with allergies, it’s the difference between staying safe and ending up in the emergency room. In 2023, over 147 food recalls in the U.S. were due to undeclared allergens. That’s not a small mistake. It’s a public health issue. And the problem doesn’t stop at food. Many prescription medications contain hidden allergens like lactose, soy, or peanut oil-none of which are required to be clearly labeled. If you or someone you care for has allergies, you need to know how to read labels the right way. Not just once. Every time.

What You Must Know About Food Allergen Labels

The U.S. Food and Drug Administration (FDA) requires nine major food allergens to be clearly labeled on packaged foods. These are: milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soy, and sesame. Sesame became the ninth allergen in January 2023, thanks to the FASTER Act. Before that, millions of people with sesame allergies had no protection. Now, if a product contains sesame-even as a tiny part of "natural flavors" or "spices"-it must say so.

There are two legal ways manufacturers can declare these allergens:

1. Within the ingredient list: The allergen’s common name appears in parentheses right after the ingredient. For example: "lecithin (soy)" or "whey (milk)".
2. A separate "Contains" statement: Right after the ingredient list, you’ll see something like: "Contains: Milk, Soy, Tree Nuts." This must be easy to find, with no other text in between.

Don’t assume "natural flavors," "spices," or "color added" are safe. These terms can hide allergens. If you see "natural flavor" and don’t know what’s in it, don’t take the risk. The same goes for "modified food starch"-it can come from wheat. Always look for the allergen in parentheses or the "Contains" line. And remember: even if you’ve bought the product before, check the label every time. Companies change ingredients without warning. In 2022, FARE reported that 28% of allergic reactions came from products people had used safely before.

What’s Missing: Medication Labels

Here’s the scary part: medications don’t have to list allergens. Unlike food, there’s no law requiring drug makers to say if their pills contain lactose (a milk derivative), peanut oil, soy lecithin, or gelatin from pork or beef. These are called "inactive ingredients"-they don’t treat your condition, but they can still trigger a reaction.

A 2023 study in the Journal of Allergy and Clinical Immunology found that 4% of American adults have allergies to medication ingredients. Many of those reactions come from hidden allergens in pills, capsules, or liquid suspensions. For example, a common generic version of a blood pressure pill might use lactose as a filler. Another brand might use corn starch. Same active ingredient. Different filler. Same risk.

So how do you know what’s in your medicine?

• Ask your pharmacist. Always. Say: "Can you give me the full list of inactive ingredients in this prescription?"
• Check the package insert (the small paper inside the box). Look for "Inactive Ingredients" or "Excipients."
• Use the FDA’s DailyMed database online. Search your drug name, and scroll to the "Description" section.
• Don’t assume generics are the same. Even two brands of the same generic drug can have different fillers.

One woman in Brisbane told me her son had a severe reaction to a generic antibiotic. The label didn’t say anything about soy. But the capsule shell contained soy lecithin. She’d never had a problem with the brand-name version-because it used a different filler. That’s why you can’t rely on past experience with medications.

How to Read Labels Like a Pro

Here’s a simple, step-by-step method that allergists recommend:

1. Start with the "Contains" statement. If it’s there, read it first. It’s the fastest way to spot major allergens.
2. Scan the ingredient list. Look for allergens in parentheses. Don’t skip over words you don’t recognize. "Casein" = milk. "Albumin" = egg. "Arachis oil" = peanut.
3. Watch for "may contain" or "processed in a facility with". These are voluntary warnings. They mean cross-contact might have happened. They’re not required, so they’re not always reliable. But if you’re highly sensitive, treat them like a red flag.
4. Check for hidden names. Soy can be listed as "textured vegetable protein," "hydrolyzed plant protein," or "vegetable gum." Wheat might be "modified starch," "maltodextrin," or "brewer’s yeast."
5. For medicines: Always ask for the full inactive ingredient list. Write it down. Keep a note on your phone.

It takes 15 to 20 seconds per product. At first. After a few months, you’ll do it in 5. Practice makes safety.

What to Do When You’re Unsure

Here’s the truth: labels aren’t perfect. Even the best ones can miss something. If you’re ever unsure:

• Call the manufacturer’s customer service line. Most have it printed on the package. Ask: "Does this product contain [allergen]?" and "Is it made in a facility that processes [allergen]?"
• Use apps like AllergyEats Scan (launched in early 2024). It uses your phone’s camera to read ingredient lists and flags allergens. Beta testing showed 92% accuracy.
• Shop with brands that label clearly. FARE’s 2023 survey found that 79% of allergy sufferers prefer brands that use both the "Contains" statement AND parenthetical labeling. They’re more consistent.
• Keep a personal allergen log. Write down every product you’ve safely used-and every one that caused a reaction. Include the batch number if possible. This helps you spot patterns.

Why This Matters More Than You Think

Food allergen mislabeling causes 40% of all food recalls in the U.S. That’s not a glitch. It’s systemic. Smaller companies have only a 76% compliance rate. Big companies? 92%. But even big companies make mistakes. In 2023, 18% of sesame-related recalls happened because sesame was hidden in "spices" or "flavors."

And it’s not just about food. The global "free-from" food market hit $68.3 billion in 2023. People are spending billions to avoid allergens. But if you’re taking medication with hidden allergens, you’re still at risk-even if you eat perfectly clean.

For parents: 78% of allergic reactions in children happen from products their families thought were safe. That’s not negligence. It’s lack of information. The system isn’t designed to make you safe-it’s designed to avoid lawsuits. You have to be your own advocate.

What’s Changing in 2025 and Beyond

The FDA is working on new rules to standardize how "may contain" warnings appear. Right now, they say everything from "may contain peanuts" to "produced in a facility that also processes tree nuts." No consistency. No clarity. By late 2025, global standards from the Codex Alimentarius may bring more uniformity.

Some companies are adding QR codes to packages. Scan it, and you get a full allergen breakdown, including cross-contact risks. But older adults and people without smartphones can’t use them. So don’t rely on them alone.

The bottom line? Labels are improving-but they’re still not foolproof. The safest approach is simple: Read every label, every time. Ask questions. Don’t assume.