What do FDA's compounding categories 1, 2 and 3 mean?

Category 1

Substances nominated with sufficient supporting information that may be eligible for the list and do not appear on another list. FDA says it does not intend to take action against compounders using them, provided specified conditions are met. FDA's 503B page adds that no safety concerns have been identified for them.

Category 2

Substances where FDA identified significant safety risks in using them for compounding. FDA's 503A page says it would consider taking action against a compounder who uses them. The 503B page says Category 1 protections do not extend to them and that FDA may enforce.

Category 3

Substances nominated without enough supporting information for FDA to evaluate them. They do not get Category 1 protections. FDA's 503B page says compounders must re-nominate with complete data.

What changed in 2025, and what “withdrawn” means

FDA's 503A page says the interim categories remain in effect, and that as of Jan. 7, 2025 the agency does not intend to place substances nominated on or after that date into them.

FDA's page on substances that may present significant safety risks has a table headed “bulk drug substances nominated but withdrawn.” BPC-157 and six other peptides are listed there with FDA's safety concerns. We did not find FDA's own definition of that heading on the pages we read, so we do not say what it means for current status.

What a category does not mean

• A category describes FDA's enforcement stance toward compounding under its interim policy. It is not a ruling on any one product.
• Categories sort nominated substances. They are not approvals, and FDA says compounded drugs are not FDA-approved.
• There are separate versions for 503A pharmacies and 503B outsourcing facilities. See our comparison.