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Drug label API that shows what changed.

The Posolix drug label API keeps every version of every FDA prescribing label. Ask for a label's history and get the sections that changed in each version, with a separate event whenever a boxed warning is added, removed or edited.

Get a beta API key See the endpoints

Free for the length of the beta.

GET /v1/labels/a1b2c3d4-.../history

{
  "set_id": "a1b2c3d4-0000-0000-0000-000000000000",
  "brand_name": "EXAMPLINIB",
  "versions": [
    {
      "version": 7,
      "effective_date": "2026-09-10",
      "events": [
        "label.updated",
        "label.boxed_warning_changed"
      ],
      "sections_changed": [
        "boxed_warning",
        "warnings_and_cautions",
        "adverse_reactions"
      ]
    },
    { "version": 6, "effective_date": "2025-11-03", ... }
  ]
}  // illustrative, fields may change in beta

Drug label endpoints.

Look up one label's history, or ask for every label change across all drugs since a date.

  • GET/v1/labels/:set_id/history

    Every version of a label, its effective date and the sections that changed from the version before.

  • GET/v1/events?type=label.updated

    All label changes across all drugs, filterable by date, sponsor and changed section.

  • GET/v1/events?type=label.boxed_warning_changed

    Only the label changes that add, remove or edit a boxed warning.

FDA label changes, section by section.

openFDA serves the current prescribing information for each drug, parsed from the manufacturer's SPL file. Older versions drop out, and nothing tells you which parts of a label moved.

Posolix stores each version under its set ID and compares it with the last one section by section. You get a list of changed sections for each version, so a new contraindication or dosing change doesn't get lost in a 40-page label.

Labels are linked to their applications, so you can go from a label change to the FDA approval behind it. Prefer email? FDA approval alerts include label changes too.

{
  "event": "label.boxed_warning_changed",
  "occurred_at": "2026-09-10",
  "label": {
    "set_id": "a1b2c3d4-...",
    "brand_name": "EXAMPLINIB",
    "application_number": "NDA2XXXXX"
  },
  "changes": {
    "boxed_warning": {
      "from": null,
      "to": "WARNING: HEPATOTOXICITY ..."
    }
  }
}  // illustrative

Who uses a drug label API.

Pharmacy and clinical software teamsKnow when drug information in your product is out of date and which section to review.

Pharma regulatory and safety teamsWatch competitor and class labels for new warnings and safety language.

Investors and analystsCatch new boxed warnings and label expansions as soon as they're published.

ResearchersStudy how safety language changes over a drug's lifetime.

Questions.

Where does the label data come from?

From the public openFDA drug label dataset, which is built from the Structured Product Labeling (SPL) files manufacturers submit to the FDA. Posolix is not affiliated with or endorsed by the FDA.

How do you identify a label across versions?

By its SPL set ID, which stays the same across versions. Each new version gets its own version number and effective date, and we store all of them.

Can I get only boxed warning changes?

Yes. Filter the events endpoint or a webhook subscription on label.boxed_warning_changed to skip routine label updates.

How much does the drug label API cost?

Nothing during the beta. Beta users will hear about pricing before it starts and get early-supporter terms.

Get a drug label API key.

Join the beta for an API key and a dashboard login, free while we're in beta.

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