What we discovered analyzing every ADHD medication in the US

Pick any ADHD drug. Pick a specific strength. Now compare the generics. For Adderall IR 10mg — the exact same drug at the exact same dose — 27 manufacturers sell products with anywhere from 4 to 9 inactive ingredients. The most different pair shares only 2 ingredients out of 14 combined.

The pattern holds across every drug. Generic Vyvanse 70mg ranges from 12 to 20 inactive ingredients depending on the manufacturer. Concerta (methylphenidate ER 36mg) ranges from 15 to 22. Sun Pharma’s generic Vyvanse has 6 ingredients that Takeda’s brand-name version doesn’t — including FD&C Red 40, an allergen-flagged synthetic dye.

These aren’t trivial differences. Different fillers affect dissolution rates. Different dyes trigger sensitivities. Different coatings change how the drug releases. A patient who responds well to one generic may have problems with another — not because the active drug changed, but because everything around it did.

Generic Vyvanse (lisdexamfetamine) manufacturers use between 14 and 20 inactive ingredients. Six ingredients in Sun Pharma’s generic aren’t in Takeda’s brand-name version. For Concerta (methylphenidate ER 36mg), the range is even wider: 15 to 22 inactive ingredients depending on the manufacturer.

Across all ADHD medications, we tracked 47 manufacturers of methylphenidate alone, each with their own formulation. These inactive ingredients affect dissolution rates, bioavailability, taste, and allergen exposure. A patient who responds well to one generic may have problems with another — not because the active drug is different, but because everything around it is.

Our database covers 1,809 products across 12 ADHD drugs with 16,729 ingredient records. We flagged 50 ingredients as potential allergens, including common synthetic dyes (FD&C Yellow No. 5, FD&C Red No. 40), lactose, gelatin, and aspartame.

Takeda (brand Vyvanse) declares 5 manufacturing facilities in their FDA filing — Cambrex for API synthesis, Patheon for manufacturing and packaging, Curia for testing, Sharp for additional packaging. All in the United States. Sun Pharma (generic Vyvanse) declares only 1 facility — Ohm Laboratories in New Jersey — despite having 18+ facilities in their global network across India, China, and the US.

This pattern extends beyond Vyvanse. For Concerta (methylphenidate), Janssen declares 4 facilities. For Adderall XR, Takeda uses the same diversified Patheon network. Many generic manufacturers declare minimal facility information or none at all — Teva, the world’s largest generic manufacturer, declares zero facilities in their Adderall SPL despite having 14 registered FDA facilities globally.

When Sun Pharma’s single facility had a dissolution failure in October 2025, all 7 dosage strengths of their generic Vyvanse were recalled simultaneously. A diversified supply chain provides resilience. A single-facility supply chain is a single point of failure.

We analyzed 2,700 FDA label versions and found 203 instances where manufacturers changed their inactive ingredients. Methylphenidate leads with 50 formulation changes, followed by mixed amphetamine salts (Adderall) with 40, and clonidine with 33.

Teva’s Adderall IR went through 7 formulation changes between 2007 and 2024 under two different owners (Barr Laboratories, then Teva after the 2008 acquisition). They swapped saccharin variants, added and removed aluminum oxide coating, switched from FD&C Blue No. 1 to its aluminum lake form, and added maltodextrin and sucrose as fillers.

Takeda’s brand Vyvanse had 6 formulation changes over 18 years — including a 2013 colorant swap from synthetic D&C dyes to iron oxide pigments, and a 2019 addition of 4 new ingredients for the chewable tablet launch. These changes happen without patient notification.

236 FDA enforcement actions across ADHD medications. Clonidine leads with 89 recalls, followed by methylphenidate (66) and dextroamphetamine (47). Sun Pharma has 8 ongoing Class II recalls for their generic Vyvanse alone — all initiated in October 2025 after their capsules failed dissolution testing during a routine 9-month stability check.

Noven Therapeutics holds the record for methylphenidate with 45 Class II recalls related to their Daytrana transdermal patch. Teva has 9 recalls across their amphetamine salt products since 2014. Most recalls are Class II — temporary or reversible health consequences — but the cumulative pattern reveals which manufacturers have systemic quality control issues.

This dataset was built entirely from publicly available FDA data sources using a multi-phase automated pipeline. No proprietary data was used.

Data Sources

Processing Pipeline

The data pipeline runs in 9 phases: NDC directory loading, DailyMed ingredient extraction, openFDA gap-filling, manufacturer/drug/ingredient normalization, ingredient description population (246 ingredients with pharmaceutical functions and allergen flags), formulation history tracking, FEI facility loading with SPL establishment cross-referencing, FDA recall fetching, and composite manufacturer ranking calculation.

Normalization

Raw data required extensive normalization: manufacturer names (319→150 after deduplication of casing, punctuation, and corporate suffix variations), drug names (39→12 after merging mixed amphetamine salt variants), ingredient names (pharmacopeial suffix stripping, dye name normalization, synonym mapping), and strength values. Manufacturers were classified as active manufacturers (125), repackagers/distributors (24), or defunct/merged (1).

Ranking Methodology

Manufacturers are scored 0–100 on a weighted composite: supply chain transparency (35%) — facility count, role diversity, US presence, redundancy, CMO identification; recall history (40%) — Class I/II/III counts weighted by recency; ingredient transparency (15%) — whether complete ingredient data is available; and formulation stability (10%). Rankings are computed per drug, with Adderall IR and XR ranked separately since they are fundamentally different formulations.

Limitations

Approximately 30% of products (primarily from repackagers) lack ingredient data because they don’t file their own DailyMed labels. FEI facility matching is name-based (79% match rate) — DUNS-to-FEI mapping would improve this but isn’t publicly available. Some detected “formulation changes” are actually relabeling (e.g., “gelatin” → “gelatin, unspecified”). The database reflects data as of the last pipeline run.

Database

The complete dataset is available as a 20MB SQLite database with 12 tables, 19 views, and 85,495 total rows. It can be queried directly with any SQLite client.

Knowledge is the first step. The dashboard lets you compare specific manufacturers for any drug, check ingredient lists for allergens, trace supply chains, and review formulation change history with exact dates and ingredient details.

If you’re experiencing side effects after a generic switch, the ingredient comparison tool may reveal differences worth discussing with your pharmacist or prescriber. If you have dye sensitivities, you can search for manufacturers whose products avoid specific ingredients.

This project is open source and relies entirely on publicly available FDA data. We believe transparency in pharmaceutical manufacturing shouldn’t require an insider.