Purple Book · biologic status
The FDA Purple Book identifies licensed biological products and shows biosimilar or interchangeable status where applicable. Those are specific regulatory determinations, not interchangeable labels for every biologic.
What the Purple Book answers
FDA describes the Purple Book as a searchable database of biological products licensed under the Public Health Service Act, including reference products and licensed biosimilar and interchangeable products. The database covers products regulated by both FDA drug and biologics centers.
A product record can show the proprietary and nonproprietary names, application number and regulatory pathway or status. The exact record and retrieval date should accompany any claim because the database changes as products are licensed or statuses are updated.
Biosimilar and interchangeable are not synonyms
A biosimilar product has met FDA’s standard for biosimilarity to a reference product. An interchangeable biosimilar has an additional FDA determination related to substitution. FDA explains that pharmacy-level substitution is also subject to state law.
The practical consequence is narrow: do not infer “interchangeable” from “biosimilar,” and do not infer that a product without an interchangeable designation is less safe or effective. Report the exact status displayed by FDA.
A biosimilarity or interchangeability statement is relational. It should name the corresponding reference product and match the correct application record.
A five-field verification card
- Proprietary and proper product names
- Biologics license application number
- Reference product relationship
- FDA-displayed biosimilar or interchangeable status
- Database retrieval date and any linked approval documents
What the database does not decide
The Purple Book does not select treatment for an individual, promise coverage or stock, or replace state-law and professional-practice requirements. Readers should bring product and prescription questions to a licensed clinician or pharmacist.
If a biologic is used around a surgical episode, the regulatory record still does not establish local procedure availability. The Surgical Workforce and Care Access hub addresses the separate facility and workforce evidence.