On August 24, 2026, FDA issued five warning letters to companies selling research-use-only peptides. All five came out of the Center for Drug Evaluation and Research’s Office of Unapproved Drugs and Labeling Compliance. All five charge the same violation: introducing unapproved new drugs into interstate commerce under Sections 505(a) and 301(d) of the Federal Food, Drug, and Cosmetic Act.
The recipients:
- NuScience Peptides LLC — Cornelius, North Carolina — read the letter
- Royal Peptides LLC — Boynton Beach, Florida — read the letter
- Peptide Partners LLC — Sarasota, Florida — read the letter
- TXP Innovations LLC d/b/a Tex Peptides — Dallas, Texas — read the letter
- Peak Performance Peptides — Phoenix, Arizona — read the letter
Each letter gives fifteen business days to respond and expressly reserves seizure and injunction without further notice.
One detail frames everything that follows: none of these companies was inspected. No facility visit, no product testing, no adverse event reports. Every allegation in every letter traces back to a website review conducted in July 2026. A reviewer read the sites, and that was enough to build the case.
Here are the four takeaways that matter for anyone operating in this space.
1. Research References and Mechanism of Action Are the Core of Every Letter, and “Educational” Framing Does Not Save Them
This is the most important point, and it is where most companies are still exposed. The bulk of each letter is FDA quoting the seller’s own descriptions of what the molecule does inside a living organism: receptor binding, downstream physiological effects, human clinical trial results, animal and rodent study findings, page after page of it.
The quoted language runs the full range of sophistication, from plain claims about enhancing insulin secretion and slowing gastric emptying to careful academic hedging about compounds “studied for” a particular effect or “considered in preclinical models.” FDA cited both. The hedge changed nothing.
The framing does not create a safe harbor. Not “for research purposes only.” Not “for educational purposes only.” Not a footnoted citation to a peer-reviewed paper. Not a disclaimer that the content is provided for informational use by qualified researchers.
The reason is structural, not stylistic. Section 201(g)(1) of the FD&C Act defines a drug to include articles intended to affect the structure or any function of the body, not just articles intended to treat disease.
FDA therefore does not need to find a disease claim on your site. It needs to find evidence that you intended the product to do something to a body. A description of mechanism of action is that evidence. So is a summary of a study measuring that effect, regardless of the species involved and regardless of whether you wrote the study or merely described someone else’s.
The practical rule that falls out of these letters: if content on your site explains what the compound does to a living organism, it is evidence of intended use. The label you put above that content does not neutralize it.
2. Bacteriostatic Water Was Charged as a Separate Unapproved New Drug
Four of the five letters name the company’s own bacteriostatic water as its own unapproved new drug violation. The reasoning is short and worth understanding precisely. Bacteriostatic water on its own is unremarkable. What made it a drug, in FDA’s analysis, is that it was offered for sale on a website that also sells injectable peptides.
From that co-location, FDA inferred that the seller intended the water to be used to reconstitute those peptides for human injection, which supplies the intended use that converts it into a drug.
The same logic reached other resources on these sites. Peptide dosing calculators and reconstitution guides were cited by name, on the theory that they provide the means to prepare an injectable product for human administration.
The broader principle: FDA reads every element of your site in light of every other element. Individual pages are not evaluated in isolation. A product that would be entirely lawful standing alone can be pulled into a drug charge by what sits next to it in your catalog.
3. Exposure Extends Well Past Your Product Pages
Two citations in this batch deserve specific attention because they reach content most companies never audit.
Royal Peptides was cited for blog content. Specifically, comparison articles discussing tirzepatide against retatrutide, including clinical weight-loss figures. This is exactly the category of SEO content that companies outsource to agencies and freelancers, publish on a content calendar, and never review again. FDA quoted it as evidence of intended use, with no distinction drawn between it and the product page copy.
NuScience was cited for content on a page it did not own. The letter references language appearing on a third-party PubChem entry that was hyperlinked from a NuScience product page. FDA attributed that content to the seller on the basis of the link. If you link to it, expect to own it.
Any meaningful audit therefore has to cover blog and SEO content, FAQs, outbound links, downloadable PDFs and certificates of analysis, email and SMS campaigns, affiliate and influencer copy, and social media, not just the pages in your store.
4. The Enforcement Target Set Is Broadening Well Past the GLP-1s
The molecules named across these five letters include semaglutide, tirzepatide, and retatrutide, as expected. But they also include survodutide, mazdutide, tesamorelin, tesamorelin and ipamorelin blends, PT-141, bremelanotide, and SS-31, elamipretide.
That range covers growth hormone secretagogues, melanocortin receptor agonists, and mitochondrial-targeted peptides. If your risk assessment assumed this enforcement wave would remain confined to GLP-1 receptor agonists and their commercial threat to approved obesity products, these letters retire that assumption.
Worth noting as well: coded and abbreviated product naming offered no protection. Products marketed under designations like “GLP-1 SEM,” “GLP-2 TRZ,” and “GLP-3 RT” were identified by molecule without difficulty, and FDA simply quoted the descriptive copy underneath each one.
What Operators Should Do Now
Every one of these five cases was built from publicly available website content. That means the exposure is entirely within your control, and it also means any company in this industry can be assessed at any time, without notice and without a visit.
At minimum:
- Audit the entire digital footprint, not just product pages: blog, FAQs, outbound links, PDFs and COAs, email and SMS, affiliate content, and social.
- Review third-party and agency-produced content you have not personally read. Cited copy that someone else wrote is still your copy.
- Examine what sits alongside your peptide SKUs, including bacteriostatic water, injection supplies, calculators, and reconstitution resources.
- Stop treating research citations and educational framing as protective. They are not, and these letters make that unusually clear.
- Preserve a record of your current site state. FDA’s review here was conducted in July, and the letters were published weeks later. Knowing what a reviewer would have seen at any given point matters if you ever need to respond.
If you have received a warning letter, the fifteen-business-day response window is short, your response becomes part of the public record, and the framing carries consequences well beyond the immediate exchange. That is not a document to draft without counsel.
LumaLex Law advises peptide companies, compounding pharmacies, and telehealth platforms on FDA regulatory exposure, marketing review, and enforcement response. If you would like to discuss these letters or have your website reviewed, get in touch.
This article discusses public FDA enforcement actions for general informational purposes. It is not legal advice regarding any specific set of facts and does not create an attorney-client relationship.
