An FDA warning letter is a written notice from the U.S. Food and Drug Administration that the agency believes your company has committed significant violations of the laws FDA enforces. FDA sends it to give the company a chance to correct those violations. Shehadeh Giannamore, PLLC represents food, beverage, dietary supplement, cosmetic, medical device, and OTC drug companies that receive these letters.
The letter names the problem. Common examples are manufacturing conditions, claims about what a product can do, and directions for use that do not match the product’s legal status. It asks for a written response within the time stated in the letter. If you disagree, you can send FDA your reasoning and the records that support it.
A warning letter is advisory. It is not a fine, a court order, or a final decision that you can challenge in court on its own. FDA still treats it as notice. If the violations stay in place, the agency can move to seizure, an injunction, an import alert, or, in some product areas, civil penalties, without sending another warning first.
What an FDA warning letter is
FDA uses a warning letter when it has decided the violations are serious enough to need prompt correction. The agency’s own description says this notice is its main way to get companies to comply voluntarily with the Federal Food, Drug, and Cosmetic Act.
A letter usually includes the company and the official it is addressed to, the product type, the office that issued it, each violation and the legal basis, and the date a response is due. FDA posts most warning letters on its website after it removes confidential information. Customers, retailers, investors, and competitors can read them.
People search for these under several names. USFDA warning letters, a warning letter from USFDA, a US FDA warning letter, and FDA letters all refer to the same document. “USFDA” is a common way to write the U.S. Food and Drug Administration. It is not a separate agency.
Not every FDA letter is a warning letter. The agency also sends untitled letters, close-out letters, and, for some drug marketing reviews, notice-of-violation letters. Tobacco retailer inspections produce their own set of letters. The section below on untitled letters, and the later note on tobacco letters, keep those documents separate.
Why your company received one
FDA sends a warning letter when it believes violations are significant and should be corrected quickly. The path to that letter is not always an inspection.
One path starts with an inspection. At the close, the investigator may leave a Form FDA 483 listing observations. FDA then reviews the 483, the Establishment Inspection Report, the evidence, and any response you sent. If the agency decides the problems meet its threshold, it issues a warning letter. An inspection tied to a warning letter is classified Official Action Indicated, which means FDA views the facility as out of compliance.
A second path never produces a 483. FDA reviews labels, websites, social media, and marketplace listings. It also samples products and reviews import entries. Dietary supplement, cosmetic, food, and OTC letters often come from disease claims or other claims that make a product look like an unapproved drug. Device letters often cite quality-system failures, complaint handling, or marketing without clearance or approval. Food letters often cite preventive controls, sanitation, allergens, or the Foreign Supplier Verification Program.
A third path is a tobacco retailer compliance check under the Family Smoking Prevention and Tobacco Control Act. Those letters focus on sales rules, including age and ID checks, rather than drug or food manufacturing.
Promised fixes do not, by themselves, stop a letter. FDA has said that corrective actions still in progress generally do not prevent a warning letter. The response after the letter, and the records that show the fixes are done, are what the agency evaluates.
Companies in this position use FDA warning letter responses to map each citation to a correction, a date, and the evidence FDA can check.
How a warning letter differs from a Form 483
A Form 483 is not a warning letter. The 483 is the investigator’s list of observations, handed to management at the end of an inspection. FDA’s own form says those observations are not a final agency determination.
The warning letter comes later, if it comes at all. It states the agency’s position that the violations are significant. Many 483s never become warning letters. A complete 483 response is the main chance to be heard before that decision.
| Point | Form FDA 483 | Warning letter |
| When it is issued | At the end of an inspection, if the investigator saw possible violations | After FDA review, when the agency decides the violations are significant |
| Who issues it | The investigator, after discussing the observations with management | FDA, often from the center or office that covers the product |
| What it is | Inspectional observations, not a final agency decision | Advisory notice of the agency’s position. Not a final agency action |
| Response window | FDA gives a detailed review to responses received within 15 business days | The letter states the deadline. See the note below before you publish a number of days |
| Public posting | FDA does not post 483s as a routine public database in the way it posts warning letters | Posted on FDA’s warning letter list after redaction |
| What can follow | A classification of NAI, VAI, or OAI, often within 45 to 90 days | Further enforcement if corrections are not made and verified. A close-out letter only after FDA checks the fixes |
NAI means no action indicated. VAI means voluntary action indicated. OAI means official action indicated. A warning letter sits with an OAI classification.
How a warning letter differs from an untitled letter
An untitled letter cites violations that FDA does not treat as serious enough for a warning letter. It does not include the warning that FDA may take enforcement action without further notice. A warning letter does include that warning.
That difference is about severity, not about whether you should answer. An unanswered untitled letter can be followed by a warning letter. FDA untitled letters still need a prompt, complete response.
Older descriptions sometimes say untitled letters cover only online marketing and are not published. Current FDA practice is broader. The agency posts many untitled letters, including letters from advertising reviews and from some inspection programs. Read the letter you received, not a general rule about the format.
What the letter asks you to do
The letter asks for a written response that covers every citation. FDA wants the correction you have already made, the correction still underway, the date each item will be finished, and the records that show the fix is real. A promise to “improve quality” without a root cause, a scope check, and attachments is the kind of reply FDA later calls inadequate.
Work from the letter’s order. For each item, state the citation, what you found when you looked beyond the example FDA used, what changed, and who owns the remaining steps. If a label claim was the problem, the response should cover the website, ads, and marketplace listings that repeat it, not only the label FDA quoted.
The practical sequence for that reply is covered in responding to an FDA warning letter. This page does not repeat those drafting steps.
Tobacco retailer letters are narrower, but they are not a template you can copy from another store. Age-verification failures and labeling failures need different corrections. There is no single sample that fits every file. A sample response to an FDA tobacco warning letter is a starting point for the issues in that letter, not a form to reuse.
After you respond, FDA may ask for updates, hold a meeting, or reinspect. For warning letters issued on or after September 1, 2009, FDA may send a close-out letter only after it has evaluated the corrections and verified that they were actually made. A statement that you will fix the problem is not enough. If a violation cannot be corrected, FDA does not issue a close-out letter. Later inspections can still review whether the corrections lasted.
Where to read the FDA warning letter list
FDA publishes warning letters in a searchable list on fda.gov, under Inspections, Compliance, Enforcement, and Criminal Investigations. You can filter by company, issuing office, subject, and whether a response or close-out letter is posted. The date on the letter and the date FDA posts it are not the same. FDA removes confidential information before posting.
Use that list to see the office that wrote your letter and the subject line FDA assigned. Do not treat a third-party tracker as the record. The letter on fda.gov is the one customers and retailers will cite.
A posted letter can outlast the inspection. Retailers and marketplaces read subject lines such as “unapproved new drug” or “CGMP.” Plaintiffs in consumer cases often quote public letters. Mark trade secrets in your response, because responses can be requested under the Freedom of Information Act.
What to do in the first days after the letter arrives
Read the letter against the records FDA relied on, and keep the envelope or delivery receipt so the deadline is counted from the right day. Stop any claim the letter identifies, including the same claim on pages FDA did not quote. Hold affected lots if the letter describes a product that is adulterated or misbranded, and tell the person who will sign the response.
Then build one reply that answers every item. Partial updates sent as separate emails are easy to lose. If the work cannot be finished inside the stated deadline, the response should say what is done, what is not, and the date of the next update. Missing the date without that explanation is what leads companies into the enforcement step they were trying to avoid.
If you want counsel to review the letter against your labels and quality records before you send a reply, contact the firm with the letter and the date you received it.
Questions companies ask after a warning letter
Are FDA warning letters public?
Yes. FDA posts warning letters on its website after redacting confidential information. The posting is the public record customers and business partners see. Your response can be requested under the Freedom of Information Act.
Does every Form 483 become a warning letter?
No. A 483 records an investigator’s observations. FDA reviews that record, the inspection report, and your response before it decides whether the violations are significant enough for a warning letter.
What happens if the company does not correct the violations?
FDA can move to further action without another warning. Depending on the product and the facts, that can include seizure, an injunction, detention of imports, or civil penalties. The letter itself is the notice.
What is a close-out letter?
A close-out letter means FDA has evaluated your corrections and verified that they were made. It applies to warning letters issued on or after September 1, 2009. FDA usually verifies corrections with a follow-up inspection. No close-out letter is issued when the violation cannot be corrected.
Where is the FDA warning letter list?
On fda.gov, in the warning letters section of Inspections, Compliance, Enforcement, and Criminal Investigations. Search by company name, issue date, or subject. That list is the official posting, not a law firm or news reprint.
Talk with counsel before the deadline in your letter
A warning letter is a notice, and it is also the file FDA, customers, and opposing lawyers will read later. The useful next step is a response that answers each citation with corrections FDA can verify. Shehadeh Giannamore, PLLC reviews these letters for companies across FDA-regulated products. Send the letter and the date you received it so the deadline is clear.
This article is general information, not legal advice. Reading it does not create an attorney-client relationship.