Hidden Allergens in Medications

Avoiding allergens in drugs you need

It's ironic that something you could take to improve your health actually could make you sick. But if you have food allergies, it's a real possibility: fillers, binders, and other ingredients in both prescription and over-the-counter medications often contain common hidden allergens.

These ingredients can be difficult to avoid, too, because of some of the oddities in how medications are labeled and the circumstances in which you may be given medicine. Read on to learn some of the ways you can keep yourself safe when dealing with medications.

Doctor checking prescription bottle
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Differences Between Medicine Labels and Food Labels

When buying over-the-counter medicines, you should know that U.S. Food and Drug Administration (FDA) regulations for labeling food and medicine don't work the same way: certain allergens that must be labeled on a food product don't need to be labeled on a drug product.

For example, "starch" on a food label means cornstarch. On a medicine label, it could mean potato, corn, tapioca, or wheat starch. In addition, wheat starch doesn't need to be explicitly labeled on medication, even though any food containing wheat must spell out that fact regarding the eight foods in the Congress-passed Food Allergen Labeling and Consumer Protection Act of 2004. Under the act, the "Big 8" FDA-regulated allergens are milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, and soybean. In 2021, the FDA ruled sesame as another one under the Food Allergy Safety, Treatment, Education, and Research.

Similarly, food manufacturers must specifically label maltodextrin that's derived from wheat, but this is not the case for maltodextrin that's used in medications. The bottom line: Don't buy a medication over the counter unless you're absolutely sure all the ingredients are safe for your diet and your food allergies.

Does Your Prescription Drug Contain Allergens?

You'll need to enlist your pharmacist's help to determine whether a medication you've been prescribed is safe. This may entail phoning the manufacturer to confirm ambiguous ingredients in the packaging the original medication was shipped in.

This is a good reason to keep all your prescriptions at the same pharmacy if at all possible; once you've found a pharmacist you trust to do this sort of legwork, it pays to maintain that relationship.

Be especially aware of excipient ingredients: these are bindings, coatings, or other inactive ingredients where allergens are especially likely to lurk. Corn and wheat are the two common allergens you'll find in a variety of excipients, but dairy, and gelatin are also not uncommon. Arachis oil, a peanut derivative, is also sometimes used in creams or other topical medications.

What to Do If Allergens Are Included

What happens when a medicine you've been prescribed includes an allergen in the pills or liquid that's shipped from the manufacturer?

In this case, you'll have two options: Either your healthcare provider may be able to prescribe you a similar medication (or a different formulation of the same medication, like a syrup or inhaled version) that's safe for you, or you may need to have your medicine specially made at a compounding pharmacy.

The compounding pharmacy option will be much more expensive. But if you can prove medical need – which your allergist can document – insurance hopefully will cover the additional expense. Because of this, consider asking your healthcare provider for first and second choice medications whenever possible at the time you get your prescription – good advice for anyone with a common food allergy or sensitivity.

At the Hospital: Precautions You Can Take

One situation where you may encounter special difficulties is during a hospitalization, especially an unexpected one. Wearing medical alert jewelry that indicates your food allergies is one step that can help, but protecting yourself during a hospital visit shouldn't end there.

Appointing a local friend or family member to act as a liaison between you and hospital staff can make a difference, especially if your condition is severe or if you may not be in a position to ask questions about medications due to drowsiness, severe pain, or other medical issues. They should ask about any medicines you're given and make sure they've been vetted for your food allergies.

In addition to excipient ingredients in pills, be especially aware of – and ask your liaison to be on the lookout for – IV solutions if you have a corn allergy. Corn-based dextrose is a common ingredient in many IV saline solutions, which are likely to be among the first therapies you'll receive during any hospital visit. Plain saline solution should be a safe alternative.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. U.S. Federal Drug Administration. Food Allergies.

  3. Hofman DL, van Buul VJ, Brouns FJ. Nutrition, Health, and Regulatory Aspects of Digestible MaltodextrinsCrit Rev Food Sci Nutr. 2016;56(12):2091-2100. doi:10.1080/10408398.2014.940415

  4. Reker D, Blum SM, Steiger C, et al. "Inactive" ingredients in oral medicationsSci Transl Med. 2019;11(483):eaau6753. doi:10.1126/scitranslmed.aau6753

By Victoria Groce
Victoria Groce is a medical writer living with celiac disease who specializes in writing about dietary management of food allergies.