FDA warning letters to compounding pharmacies: what they mean, and who holds one

A warning letter is the FDA telling a company, in writing and in public, that it believes the company is breaking the law, and giving it fifteen working days to answer.

It is not a fine, a licence suspension, a recall, or a court finding. Nobody has been to court. The letter states the agency's position after an inspection, lists what it found, and says what happens if the company does not fix it — the standard closing sentence warns of seizure and injunction.

Two documents usually come before it. An investigator visits the facility and leaves a Form 483, a list of observations written on the spot. The company responds. If the FDA thinks the response is inadequate, or the findings are serious enough, the district office escalates to a warning letter, often six to twelve months after the inspection. Every letter in the register below names its inspection dates, and the gap is routinely long: GenoGenix was inspected in July 2025 and received its letter in January 2026.

Almost every letter in the register is filed under one subject line: Compounding Pharmacy / Adulterated Drug Products. Behind that heading sit three recurring allegations.

Insanitary conditions. Sterile products made in conditions the FDA judges incapable of assuring sterility — inadequate airflow studies, cracked equipment, environmental monitoring that misses contamination. Under section 501(a)(2)(A) a drug prepared under insanitary conditions is adulterated as a matter of law, whether or not any particular vial was contaminated.

CGMP failures, for 503B outsourcing facilities, which are held to manufacturing standards: batch discrepancies not investigated, aseptic areas not monitored, quality oversight too thin to catch either.

Failing the conditions of the exemption. A compounding pharmacy is legal because it operates inside an exemption — 503A for patient-specific prescriptions, 503B for outsourcing facilities. Compound from a substance that is not eligible, skip the required labelling, fail to report adverse events, or, under 503A, regularly make copies of an approved drug without a prescriber's documented reason why the patient needs something different, and the exemption does not apply. What is left is an unapproved new drug ^[2].

This is a different charge from the one in our report on the letters to research-peptide sellers. Those cases begin with the FDA reading a website and end with "you are selling an unapproved new drug." These begin with an investigator walking through a cleanroom. One is about what a company said; the other is about how it made things.

Honestly: it depends, and the letter itself often says.

A letter does not shut a pharmacy down, and it does not by itself mean the vial in your fridge is unsafe. Many allegations are about process and documentation — real failures, but not evidence about any specific batch.

Some letters are more concrete than that, and those are the ones to read. Three examples from the register:

GenoGenix. Three patients received NAD+ from the same vial, lot GG121624-023, and were directed to the emergency room with low blood pressure, uncontrollable shaking, shivers and body aches. Testing of that lot found bacterial endotoxins at 3,360 EU/mL.

Boothwyn Pharmacy. A lot of compounded semaglutide 2.5 mg/mL tested at 79.9% of its labelled strength; two lots of tirzepatide 10 mg/mL at 86.8% and 89.1%. A separate lot — tirzepatide 17 mg/mL with glycine and methylcobalamin — was released after failing a sterility test. At the time of inspection, 19 of 23 out-of-specification investigations were still open. FDA has since taken this letter off its website: the address now returns an error and the letter no longer appears in FDA's warning-letter search. The link goes to the Internet Archive's copy of FDA's page, captured on 14 June 2026. FDA has not said why it was removed, and we do not guess.

ProRx. Tirzepatide injection 27 mg/3 mL and semaglutide multidose vials were subject to voluntary recall.

A subpotent GLP-1 is not a safety event in the way a contaminated vial is, but it is the reason a dose that worked for someone else may do nothing for you. If a letter names a product you were dispensed, the practical step is to ask the provider which pharmacy filled it and which lot — a legitimate provider can answer both.

The register below starts in January 2025 and covers the pharmacies in our own directory and any letter that names a peptide or GLP-1 product. For any other pharmacy, the source is public and takes two minutes.

Search the FDA's warning letter database by company name ^[1]. Read the "Response Letter" and "Closeout Letter" columns as well as the letter: a posted closeout means the FDA considers the matter resolved. An empty closeout column does not mean the opposite — the agency posts selectively, and its own notice says a letter may have been followed by interaction that changed the regulatory status.

Two traps. Pharmacies trade under names that differ from the ones on their letters: the Medivant letter is addressed to Tailstorm Health Inc., and ReviveRx as Revive Rx LLC. And a 503A pharmacy is inspected mainly by its state board, not the FDA, so absence from the federal database is weaker evidence for a 503A than for a 503B.

Every FDA warning letter from January 2025 on to a pharmacy in our directory. When a pharmacy in this table had been warned before, its earlier letters back to 2019, where FDA's own list of actions against compounders begins ^[3], are here too: the same problems coming back is part of the record. Newest first. A pharmacy with more than one letter has a row for each.

Close-out letters have since been posted for two of these: Medivant (March 23, 2026) and MedisourceRx (July 27, 2026). A close-out letter means the FDA has evaluated the company's corrective actions and considers the matters in that letter addressed; it says nothing about later inspections. No response or close-out letter has been posted for the others as of the portal's currency date below.

From January 2025 we also record every FDA warning letter to a compounding pharmacy that is not in our directory, when the letter names a peptide or GLP-1 product we cover: semaglutide, tirzepatide, NAD+, glutathione and the like. Letters about other products are left out. Newest first.

This register is built from two FDA sources and nothing else: the warning-letter portal ^[1] and FDA's list of inspections, recalls and other actions against compounders ^[3]. No entry here comes from trade coverage, and every row links to the letter it describes so you can read the original rather than our summary of it.

FDA takes older letters off its website. When a link to a letter breaks, the row is pointed at the Internet Archive's copy of the FDA page, which is also where FDA's own list of compounding actions sends readers for those letters.

We re-read both sources at least every 120 days; the date they were last read is in the references below.

The rule we hold ourselves to: from January 2025, no letter to a pharmacy in our directory is skipped, and no letter that names a peptide or GLP-1 product is skipped, whichever pharmacy receives it. If a pharmacy in our directory is marked as holding a letter and has no row here, the page does not publish.