What's really in your medication?
The FDA's ingredient data is incomplete. We built AllergenMaps to show you what the label doesn't.
Who We Are
We are PharmD students at Purdue University looking to make an impact on public health. We started this project in September of 2025 after realizing the extreme disconnect in information between excipients and the allergies they may cause. We came to this realization through our experiences working in community pharmacies, as well as Kai's personal experience shaped by his Celiac Disease diagnosis.
Doctors and pharmacists often focus exclusively on active ingredients, overlooking patients with allergies to inactive ingredients. If a patient is allergic to an excipient, determining whether their medication could be a trigger is a painstaking process. It often means spending hours on hold with drug manufacturers or searching through various databases for information that may not even exist.
AllergenMaps seeks to streamline this process, saving time for both patients and pharmacies while giving patients confidence that their medication will not make them sick.
— Simon & Kai, Founders
A Personal Mission
“I first learned how serious this problem was around three months after my celiac diagnosis, when I had to take a course of antibiotics. Despite maintaining a strict gluten-free diet, the antibiotics I had received contained a hidden source of gluten that was missed by myself and everyone on my healthcare team. No one had even mentioned that this was even a common issue amongst those with celiac (or anyone with an allergy). This experience led me down a rabbit hole where I learned about the shocking lack of awareness around this issue despite the fact that it affects millions of Americans every day. It was then when I decided I was going to work to improve public health outcomes and help the millions who are affected by this problem.”
Kai
Co-Founder
Meet Our Team
Combining pharmaceutical science, data engineering, and patient advocacy.
Simon & Kai
Co-Founders
PharmD students at Purdue University with firsthand experience in community pharmacy and personal motivation to solve the excipient transparency problem.
Alex
Lead Developer
Full-stack developer responsible for building and maintaining the AllergenMaps platform, data pipeline, and allergen mapping engine.
The Transparency Gap
Active ingredients typically account for just 5–10% of a drug's weight. The remaining 90–95% consists of excipients (inactive ingredients or fillers). The FDA has approved around 200 excipients, many of which contain common allergens such as gluten, lactose, gelatin, artificial dyes, and peanut oil.
Despite their prevalence, excipients are not consistently disclosed in a clear or accessible way on prescription labels. Patients with allergies or autoimmune conditions, such as celiac disease, lactose intolerance, or severe peanut allergies, face significant challenges determining whether their medications are compatible with their needs.
Over 90% of prescription medications contain potential allergen fillers like lactose, gluten, or corn derivatives.
Labeling requirements vary globally and in the U.S., FALCPA allergen disclosure laws explicitly do not apply to pharmaceutical drugs.
Critical Insights
What We Discovered
Once we started pulling data from the FDA, we ran into a problem we hadn't anticipated. Store-brand medications from major big-box retailers were showing up in our database with almost no inactive ingredients. A bottle of store-brand ibuprofen listing 15 ingredients on the back of the box would appear in the FDA's electronic database with just one entry: “WATER.”
This isn't technically illegal. The FDA requires that all ingredients appear on the physical label, but it doesn't meaningfully audit the electronic filings manufacturers submit. Store brands comply with the letter of the law by printing everything on the packaging. They just don't bother filling out the digital fields correctly.
The consequence is that any tool relying solely on the FDA's structured data would show store-brand medications as nearly allergen-free. For a patient with a PEG allergy comparing a name-brand tablet to a store-brand alternative, that's a real problem. We built additional systems to detect and recover this missing ingredient data.
The Spelling Problem
The FDA's ingredient data is full of typos. Not a few edge cases. Thousands of them. There is no spell-check, no validation, and no one at the FDA reviewing whether “POLYETHLENE GLYCOL” should be “POLYETHYLENE GLYCOL” before the filing is accepted.
We see truncated names, transposed letters, and ingredients split across fields in ways that make no sense. Some labels list the same ingredient three different ways across three different products from the same manufacturer.
Our proprietary standardization system maps every raw ingredient string to a clean, verified name in our taxonomy — handling typos, truncations, and inconsistent formatting automatically. Anything the system isn't certain about is reviewed by our team before it appears in results.
Like the store brand problem, this is a data stewardship failure. We think patients deserve better, which is why we built AllergenMaps the way we did rather than just passing the FDA's raw data through. Read more on our cross-contamination and regulatory gaps pages.
Our Solution
AllergenMaps gives patients and providers a single place to check any medication for allergen risks, without calling manufacturers or cross-referencing databases manually.
For Patients
- check_circle Search any medication without consulting a manufacturer
- check_circle Set your allergen profile once and see flags instantly
- check_circle Compare manufacturer versions to find the best option
For Healthcare Providers
- check_circle Look up medications by NDC, active ingredient, or drug class
- check_circle Preemptively check for allergens before prescribing
- check_circle Avoid prescribing a medication that triggers patient allergies
How It Works
Data Ingestion
We ingest drug label data from official FDA sources, covering hundreds of thousands of drug labels with inactive ingredient lists.
Ingredient Standardization
Our proprietary system standardizes ingredient data from FDA sources into a consistent format, with built-in quality checks and expert review to ensure accuracy.
Allergen Mapping
Each excipient is mapped to a broad range of allergen categories — including dairy, corn, gluten, dyes, and more — based on FDA guidance and clinical research.
Three-Stage Flagging
Each medication is flagged relative to your allergen profile, so you can make informed decisions at a glance.
Vaccines
Like oral medications, vaccines contain inactive ingredients that matter to patients with allergies. But vaccine ingredients have also been the subject of widespread misinformation. As certified immunizers through the American Pharmacist's Association, Simon and Kai feel a responsibility to address both issues: helping patients with real allergen concerns while clearing up misunderstandings about ingredients like aluminum salts, ethylmercury, and formaldehyde that are mischaracterized as dangerous.
For more information about vaccine ingredients, visit our Learn page.
Ready to see what's really in your medication?
Have questions, feedback, or data corrections? Reach us at allergenmaps@gmail.com or visit our contact page.
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