Peptide Library

FDA status of peptides

Whether a peptide is legal in the US depends on the product: an approved drug, a compounded drug and a research chemical are treated differently. This page explains the difference and shows where each peptide in the library stands. It covers US federal status only and isn't legal or medical advice.

Last compared with FDA's lists on October 30, 2026.

Three kinds of status

FDA-approved
FDA has reviewed the drug for a specific labelled use. Approval covers that product and that use, not the compound in every form.
Compounded
A pharmacy prepares the drug itself. Section 503A covers state-licensed pharmacies filling individual prescriptions, and section 503B covers registered outsourcing facilities. Compounded drugs are not FDA-approved.
Research-only
The compound has no FDA-approved medical use. It may be sold for laboratory research, which is not approval for use in people.

On FDA's compounding lists

These FDA lists track substances nominated for use in pharmacy compounding. Being on a list is not FDA approval and doesn't mean a product is safe or effective.

503A Category 1

Nominated substances FDA has under evaluation.

503A Category 2

Substances for which FDA identified significant safety risks in compounding.

503A Category 3

Substances nominated without adequate support.

503B Category 2

Substances for which FDA identified significant safety risks in outsourcing facility compounding.

Nominated, then withdrawn

Substances that left Category 2 after their nominators withdrew them. Withdrawal isn't a safety finding: FDA's page still describes potential risks for each one.

July 2026 advisory committee

FDA's Pharmacy Compounding Advisory Committee scheduled these peptides for discussion on July 23 and 24, 2026. FDA staff's briefing documents weighed against adding each one to the 503A bulks list. A committee gives FDA advice and doesn't decide, and FDA had posted no minutes or outcome when we last checked.

FDA-approved compounds in the library

Each approval covers a specific product and labelled use.

Withdrawn or rejected

These left the market or were rejected for approval, so none is an approved product.

Studied under an Investigational New Drug application

These have been in clinical development and aren't approved for marketing.

Not FDA-approved

121 profiles in the library have no FDA approval. Each profile's Regulatory section shows its status.

Common questions

Are peptides legal in the US?

It depends on the product, not on the word peptide. FDA-approved peptide drugs are sold as medicines, usually by prescription. A compounded peptide needs a prescription and a substance that qualifies for compounding. Peptides sold for laboratory research aren't approved for use in people. State rules can also apply, and this page isn't legal advice.

Is a compounded peptide FDA-approved?

No. Compounded drugs aren't FDA-approved, so FDA hasn't reviewed a compounded product's safety, effectiveness or quality before it's sold.

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

They're FDA's groups of bulk substances nominated for compounding under section 503A. Category 1 is under evaluation, Category 2 raised significant safety risks, and Category 3 was nominated without adequate support. FDA says it doesn't intend to place substances nominated on or after January 7, 2025 into these categories.

Why did peptides leave Category 2 in 2026?

FDA lists them as withdrawn by their nominators. That isn't a safety finding: FDA's page still describes potential safety risks for each one.

What happened at the July 2026 advisory committee?

FDA's Pharmacy Compounding Advisory Committee scheduled seven peptides for discussion on July 23 and 24, 2026. FDA staff's briefing documents weighed against adding each of them to the 503A bulks list. A committee gives FDA advice and doesn't decide. FDA had posted no minutes or outcome when we last checked on October 30, 2026.

FDA sources