Run an FDA background check on a peptide supplier: warning letters, close-outs and import alerts

What this check can and cannot tell you

Analytical certificates answer questions about a lot. Regulatory history answers a different question: has FDA publicly raised concerns about this company, and what happened next? Buyers ask how to look this up quickly and how to write it down so a colleague can repeat it.

This is a desk method using FDA pages reviewed on 13 October 2026. It does not cover state actions, other countries' regulators, civil litigation or private complaints, and it does not rate any supplier.

Step 1: search the warning-letter list

FDA's warning-letter page lets you filter by issuing office, letter issue date, posted date, year and whether a response or close-out letter exists. [1] Search the legal entity name, trade names, website domain and any parent company. Note that the list is sorted and filtered by posted date, which can differ from the letter date.

FDA describes a warning letter as notice of what it believes are significant violations of federal requirements, with a request for a response within a set time; the recipient may submit its reasoning if it disagrees. Some drug marketing letters are redacted to remove confidential information. [2]

Step 2: read close-out and response columns carefully

FDA says it may issue a close-out letter after evaluating corrective actions, and will not issue one based only on representations that action will be or has been taken; corrections usually must be verified, typically by follow-up inspection. FDA also states that later inspections may reassess whether corrections are adequate and sustainable. [2]

Record a close-out as "FDA issued close-out letter dated D," not as "the company is compliant." Record a posted response as the company's position, not as FDA's acceptance.

Step 3: search import alerts

FDA uses import alerts for products with a history of known violations. Firms or products on an alert's red or yellow list are subject to detention without physical examination, while a green list names firms or products exempt from that detention under the alert. Search by firm name in double quotes to avoid loose matches, or browse by country, industry or alert number. [3]

If a match appears, record the alert number, list colour, firm name exactly as shown and the alert's last published date. Do not assume a similarly named firm is the same entity; match addresses where the alert shows them.

Step 4: separate listing from approval

Suppliers sometimes cite FDA registration or an NDC number. FDA states that NDC assignment does not denote approval and that the NDC Directory includes unapproved drugs, and that registration or listing alone does not denote approval. [4] [5] Record these as listing facts only.

A fictional worked record

An invented supplier, Example Peptide Co., trades as two website names. The warning-letter search finds one posted letter for the second trade name with no close-out; the import-alert search finds no match for either quoted name. The worksheet entry lists both names, both searches, the letter date and subject, and "no close-out shown on 13 October 2026."

The reviewer's decision is to hold the order pending a compliance review, not to declare the supplier unlawful. The download provides the same columns with blank rows for your own search.