Inactive ingredients in medications can include fillers, binders, coatings, and preservatives that may trigger allergic reactions or sensitivities, even when the active drug is tolerated. Inactive ingredients can cause allergic reactions and sensitivities. Learn why checking inactive ingredients in medications is important before you take them.
When people think about medication allergies, they often focus only on the active ingredient. However, many reactions are caused by inactive ingredients, also known as excipients.
Inactive ingredients may serve important functions, such as:
- Holding tablets together
- Improving stability or shelf life
- Making pills easier to swallow
- Enhancing appearance
Despite being labeled “inactive,” these ingredients are not always harmless for everyone.
Common Inactive Ingredient Concerns
People frequently check inactive ingredients due to sensitivities or allergies related to:
- Milk or milk derivatives
- Lactose or lactose monohydrate
- Gelatin
- Corn-based ingredients
- Preservatives and coatings
Why This Matters
Inactive ingredients can vary by:
- Manufacturer
- Dosage form (tablet, capsule, liquid)
- Strength
- Brand vs. generic
Two medications with the same name may not have the same inactive ingredients.
How to Verify Ingredients
Always review the exact product label for the medication you are taking. Ingredient information should never be assumed based on drug name alone.
RxAllergyScan helps identify inactive ingredients by comparing medication label data against known allergens and sensitivities.
NOTE: Generic medications may have different formulas depending on the manufacturer. To confirm the exact ingredients used, consult your pharmacist.
Tip for generics/store brands: Use the exact name as it appears on the bottle, e.g., “Equate” instead of “Walmart”, “GoodSense” instead of “Walgreens”, “Kirkland” instead of “Costco”. If nothing shows up, try leaving Manufacturer blank or searching the generic name only.