HQ Team
July 21, 2026: Every prescription drug sold in the United States carries labelling that the FDA treats as a legal document, not just a package insert. All manufacturers, big or small, must adhere to FDA rules to get their product approved.
According to the agency’s own guidance, human prescription drug labelling must summarise the essential scientific information a doctor or patient needs to use a medicine safely and that information is split into three parts: the Prescribing Information (PI), FDA-approved patient labelling (which includes Medication Guides, Patient Package Inserts, and Instructions for Use), and carton and container labelling.
Where the rules actually live
The Prescribing Information format follows what the FDA calls the Physician Labeling Rule, or PLR — a content-and-format standard set out in 21 CFR 201.56 and 201.57 that dictates everything from the order of sections to how warnings, contraindications, and overdose information must be presented. The FDA maintains detailed guidance and sample templates for this format, though the agency is explicit that no single template captures every regulatory requirement; sponsors are expected to cross-check submissions against the full text of the regulations.
Current versus approved labelling can differ
One distinction the FDA flags for industry is that “current” or “in-use” labelling — the version searchable on NIH’s DailyMed or the FDA’s own FDALabel tool — is not always identical to the last version the agency formally approved, which is what appears on Drugs@FDA. Companies can make minor editorial updates (such as a distributor’s name change) through an annual report, or moderate safety updates (like a new warning) through a “Changes Being Effected” supplement that is still under FDA review when it first appears. That gap matters for anyone citing drug labelling as a source, since the most recently approved version and the version currently in circulation are not always the same document.
Databases worth knowing
For verification, the FDA points users to several searchable tools: DailyMed and FDALabel both draw on the same underlying data but display results differently; Drugs@FDA holds the formally approved labelling along with FDA staff reviews; and the Drug Safety-Related Labeling Changes database tracks recent safety-driven edits, whether company-initiated or FDA-mandated under Section 505(o)(4) of the FD&C Act.
The FDA considers a substance a drug if it falls under any one of the following categories:
- The substance is recognized by an official drug formulary, including analgesics, anti-inflammatory agents, antibacterials, anticonvulsants, and others.
- The substance is used in the diagnosis, mitigation, cure, treatment, or prevention of diseases. This category also includes supplements.
- The substance is a component of medication but not part of a medical device. Medical devices include items such as respirators and masks.
- The substance is not a medical device, but it is used in healthcare.
- The substance is a biological product such as tissues, vaccines, or recombinant proteins.
As of March 2026, this remains the FDA’s current framework, published on its labelling resources page for industry, healthcare professionals, and patients alike.
For detailed information please refer to FDA — Labeling Resources for Human Prescription Drugs
