How Does FDA Judge Intended Use on a Peptide Website? A Self Audit (2026)

How does FDA judge intended use on a peptide website?

In all 3 FDA warning letters to peptide sellers we read, dated March 31, 2026 and August 24, 2026, FDA wrote that the research use only wording on the label did not settle the question, because "evidence obtained from your website establishes that your products are intended to be drugs for human use" (FDA). The regulation those letters cite, 21 CFR 201.128, says this intent "may, for example, be shown by labeling claims, advertising matter, or oral or written statements" (eCFR).

That is the one skill this guide teaches: how FDA says intended use is shown, and how to make a complete inventory of what your own store says, product by product, so you see your words the way a reviewer reads them. It takes 7 steps. Each step is shown on a real page we captured on October 26, 2026, and each one ends with a self check you run on your own catalog.

This guide gives no verdict on your store, no medical guidance and no legal advice. It does not make any product lawful to sell, and it is not a way to keep anything out of view. What it produces is an honest record you can take to a lawyer who handles FDA matters.

What will you be able to do after this guide?

You will be able to do four things without help:

1. Name the three ways 21 CFR 201.128 says intent may be shown, and point to where each one appears on your own site.

2. Build a sheet that holds every sentence your store publishes about each product, across every channel you control.

3. Mark the sentences that use the kinds of wording FDA quoted as evidence of intended use in its 2026 peptide letters, without deciding for yourself what those sentences mean in law.

4. Read the prescription, pharmacy and research chemical lines in six platform policies, and record, with a date, what those pages do not say.

You will not be able to say whether your store is compliant. Nobody can say that from a checklist, and this guide never tries.

Why this lesson and not another?

We tested three candidate lessons against the same captured pages before writing. The first taught readers to scan platform policies for trigger words. The second taught readers how FDA says intended use is shown and how to inventory their own copy. The third taught readers to treat a policy that never names their product as unknown rather than as permission.

Each candidate was argued by a separate advocate, and an independent judge checked all 19 quotes the advocates used against the captured pages and scored the three on five criteria: transfer across platforms, depth of verified sources, whether a reader can do it alone today, whether it stays inside a safe boundary, and whether a reader can check it on their own catalog. The first two tied at 20 points of 25 and the third scored 14. The judge chose the second lesson, because it rests on the regulation, the statute and three letters that all say the same thing, and because a keyword scan can come back clean while a store's own sentences say something else.

The two other lessons are not discarded. Step 6 below is the platform reading from the first candidate, and step 7 is the dated record of silence from the third.

What does "intended use" mean in the regulation?

The definition sits in 21 CFR 201.128, titled Meaning of intended uses in the eCFR text we captured. Its central sentence says the words "refer to the objective intent of the persons legally responsible for the labeling of an article (or their representatives)" (eCFR).

The next sentence lists where that intent can be found: "The intent may be shown by such persons' expressions, the design or composition of the article, or by the circumstances surrounding the distribution of the article." That gives you three channels to audit, and only the first is about words.

The regulation also gives examples of the first channel: "This objective intent may, for example, be shown by labeling claims, advertising matter, or oral or written statements by such persons or their representatives." Oral statements count, so a phone call or a chat reply is in scope, not only the website.

The current text carries the citation "86 FR 41401, Aug. 2, 2021". Some articles still quote older wording of this section that is no longer in force, so read the section on eCFR itself rather than a copy of it.

What does the statute say a drug is?

The regulation explains intent. The statute that uses it is the definition of a drug in 21 U.S.C. 321(g)(1). Two of its four clauses turn on intent: the term covers "articles intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in man or other animals" and "articles (other than food) intended to affect the structure or any function of the body of man or other animals" (Cornell LII).

Both clauses turn on the word intended. That word is why 21 CFR 201.128 matters to a research peptide store. In each of the three letters below, FDA tied the two together, writing that the products were drugs "because they are intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease" and then pointing to the store's own pages as the evidence (FDA).

What did FDA cite in its 2026 peptide letters?

We read three warning letters that FDA's Center for Drug Evaluation and Research sent to online peptide sellers in 2026. Each one followed a review of the seller's website, each one quoted the seller's own disclaimer, and each one said that the website, not the disclaimer, showed the intended use.

The product counts are our count of the products each letter lists by name. The Gram letter says FDA "reviewed your website at https://grampeptides.com from January to March 2026"; the other two say violations "were identified and documented during a review of your website" in July 2026.

The sentence that matters most for this guide appears in all three. The Peptide Partners letter puts it this way: "Despite statements on your product labeling marketing your products" for research use only, "evidence obtained from your website establishes that your products are intended to be drugs for human use" (FDA). Read that as a description of what FDA wrote to three other companies, not as a ruling about your store.

Each letter then introduces its evidence with the same words: "Examples from your product labeling, including on your website, that provide evidence of the intended use (as defined in 21 CFR 201.128) of these products as drugs include, but may not be limited to, the following:" (FDA). What follows in each letter is a list of web addresses of product pages and the sentences FDA copied from them. That structure, a page address followed by quoted sentences, is the exact shape of the sheet you will build in step 2.

Step 1: Where does your store describe its products?

Start with a list of places, not sentences. 21 CFR 201.128 names "labeling claims, advertising matter, or oral or written statements by such persons or their representatives" (eCFR), and FDA's letters looked at "product labeling, including on your website" (FDA). So the list has to reach past the product page.

Write down every channel you control. For most online stores the list includes:

• every product page, including the short description, the long description, tabs, and any text in images
• category and collection pages, and their introductions
• blog posts, guides and research summaries on your own domain
• order confirmation, shipping and follow up emails, and any newsletter
• social media profiles and posts, including pinned posts and replies
• paid ads, affiliate pages and coupon pages that point to your store
• support macros, chat scripts and saved replies
• the vial label, the box, and any insert or card in the package
• what sales staff or affiliates say on calls, in direct messages and in videos

The last item is easy to skip. The regulation names "representatives", so an affiliate's video about your product is part of the record even though you did not write it.

Self check 1. Count the channels on your list. If any channel on the list above exists for your store and is missing from your list, add it now. Your list passes when every channel your store publishes through appears on it, including the ones you do not write yourself.

Step 2: Have you copied every sentence into one sheet?

Now copy the words. Make one sheet with five columns: product, channel, page address or location, the exact sentence, and the date you copied it. Copy sentences exactly as published, typos included, because the FDA letters quote pages word for word and attach the address of each page.

Work one product at a time. For each product, go through every channel from step 1 and paste every sentence that mentions that product or the compound it contains. Include headings, bullet points, image text, alt text and the questions and answers on the page. Do not skip a sentence because it looks harmless; you are building a record, not making judgments yet.

Self check 2. Pick 3 products at random. For each one, open every channel on your step 1 list and count the sentences about that product. Compare the count with the rows in your sheet. Your sheet passes when the two counts match for all 3 products.

Step 3: Which sentences describe what a product does in a body?

This is the step where most of the evidence in the three letters sits. The statute defines a drug partly as an article "intended to affect the structure or any function of the body" (Cornell LII), and the letters quoted sentences from product pages as evidence of that intent.

Here is one sentence FDA quoted from a product page in the NuScience letter, chosen because it contains no health claim of its own: "GLP-2 Tirz, a research peptide of significant interest, is known for its dual agonist activity on glucagon-like peptide-2 (GLP-2) and glucose-dependent insulinotropic polypeptide (GIP) receptors." (FDA). The sentence calls the product "a research peptide" and still appears in the list FDA introduced as "evidence of the intended use". The research framing did not take it off the list.

We do not repeat the other sentences FDA quoted, because several of them describe effects on the body, and this guide does not restate health claims. You can read every quoted sentence in the letters themselves, linked in the sources below.

Go through your sheet and add a sixth column called describes an effect. Mark a sentence yes when it says, in any form, what the product or its compound does to a body, an organ, a body system, a condition, or a model of a condition. That includes sentences framed as what studies found, what research suggests, or what a compound "is known for". Mark it yes when you are unsure. Do not decide what a yes means in law; that is the lawyer's question.

Self check 3. Ask someone who did not write your copy to mark the same 3 products from self check 2 without seeing your marks. Your marking passes when every sentence they marked yes is also marked yes on your sheet. If they marked a sentence you did not, your rule is too narrow, so widen it and run the sheet again.

Step 4: What do you sell beside each product, and how is it offered?

The regulation names two channels that are not sentences: "the design or composition of the article" and "the circumstances surrounding the distribution of the article" (eCFR). The letters show what that can look like in practice.

The NuScience letter did not stop at the peptides. It also named the store's bacteriostatic water, writing that the firm offers its Bacteriostatic water for Peptides (BAC Water) "for sale to be used to reconstitute the peptide products sold on your website" (FDA). The Peptide Partners letter did the same for a product it lists as "Reconstitution Solution (BAC)" (FDA), and the Gram letter lists a bacteriostatic water among the three products it names (FDA).

So the product mix itself was part of what FDA wrote about. Add a second tab to your sheet. For each product, list what is sold with it or near it: accessories, solvents, kits, bundles, frequently bought together boxes, and the category it sits in. List how it is offered too: the names of bundles, the order of products in a kit, and any subscription or refill offer.

Self check 4. For each product, open its page and its cart as a buyer would and write down every other item the store suggests or bundles with it. Your second tab passes when every suggested or bundled item appears in it, with the page where the suggestion shows.

Step 5: What can your disclaimer not do?

Every store in the three letters had a disclaimer, and FDA quoted each one. The Gram letter quoted "Research Use Only" and "not intended for human consumption, medical use, or veterinary use" (FDA). The NuScience letter quoted "for laboratory, research, and analytical use" (FDA). The Peptide Partners letter quoted "for research use only" and "not for human or veterinary use" (FDA).

In all three, the disclaimer was followed by the same conclusion that "evidence obtained from your website establishes that your products are intended to be drugs for human use". The letters show that a disclaimer is one statement among many, and the regulation explains why: it says intent may be shown by "the circumstances surrounding the distribution of the article", not only by the label (eCFR).

Copy your own disclaimer into the sheet like any other sentence, and record every place it appears. Then read it next to the yes rows from step 3. The question for this step is not whether your disclaimer is good enough. It is whether your sheet shows sentences that say something different from it. That contrast is exactly what the three letters set out, so it is the thing to take to your lawyer.

Self check 5. For each product, count the rows marked yes in step 3 that appear on the same page as your disclaimer. Write that count next to the product. Your step passes when every product has a count, including the ones where the count is 0.

Step 6: What do the platform policies say on top of FDA?

FDA is not the only reader. The marketplaces and processors a store depends on publish their own rules, and those rules are written in their own words. None of the six platform pages below uses the phrase "intended use" as a legal test, so do not assume a platform applies 21 CFR 201.128. Read each line as written.

The one Amazon mention of the word is in its list of prescription drugs, which names "both over-the-counter and prescription GLP-1 (Glucagon-like peptide-1) agonists" (Amazon). The Stripe line sits in its list of prohibited businesses, next to "Pseudo-pharmaceuticals or nutraceuticals that are not safe or make harmful claims" (Stripe). The Stripe line is the only one of the six that names research chemicals at all, and it ties the rule to labeling, which is why your step 2 sheet matters to a processor as well as to FDA.

Add a third tab to your sheet with one row per platform you use or plan to use. Paste the line above, the page address, and the date you read it. Then read each line against your own catalog: which products could the words "prescription", "pharmacy", "unapproved" or "labeled" reach, in that platform's own wording?

A row with no match does not mean the platform allows the product. It means only that the line you read does not name it. The platform guides on this site quote each policy in full: Amazon, eBay, Square and Stripe.

Self check 6. For every platform row, write one of two words next to each product: named if the platform's line uses a word that describes the product, or not named. Your step passes when no cell on the tab is blank and no cell says allowed.

Step 7: What do the platform pages not say?

Silence is a finding too, but only when it is recorded with its date and its page. On October 26, 2026, the word "peptide" appeared 0 times in the eBay, Square, Stripe, PayPal and Braintree pages we captured, and once on the Amazon page, in the GLP-1 line quoted above. None of the six pages describes a research use only category.

That is a fact about those pages on that day. It is not permission, and it is not a prohibition. Policies change, and a page that is silent today can name a category next month. The Square terms we captured, for example, print "Last updated: July 30, 2026" on the Payment Terms (Square); a date like that is the thing to record.

Add two columns to your platform tab: words searched and result on date. Search each policy page for "peptide", "research", your product names and your compound names, and write what you found and when. Read every page again on a fixed schedule, and keep the old rows instead of overwriting them.

Self check 7. For each platform, your tab should show the page address, the words you searched, the count for each word, and the date. Your step passes when all four are filled for every platform, and when an earlier reading is still on the sheet after a later one is added.

What does this audit not tell you?

The sheet tells you what your store says. It does not tell you what that means in law, and there are three reasons it cannot.

First, the regulation reaches beyond words. Intent "may be shown by such persons' expressions, the design or composition of the article, or by the circumstances surrounding the distribution of the article" (eCFR). Changing sentences does not change what a product is, what it is sold with, or who buys it. An audit that looks only at copy leaves two of the three channels open.

Second, the regulation says intent can follow the seller, not the maker: "If, for example, a packer, distributor, or seller intends an article for different uses than those intended by the person from whom he or she received the article, such packer, distributor, or seller is required to supply adequate labeling in accordance with the new intended uses." A supplier's paperwork does not answer for your own pages.

Third, FDA is not the only regulator of what a store says. The FTC Act makes it unlawful "to disseminate, or cause to be disseminated, any false advertisement" for the purpose of inducing "the purchase of food, drugs, devices, services, or cosmetics" (Cornell LII). Its definition of a false advertisement takes into account "the extent to which the advertisement fails to reveal facts material in the light of such representations" (Cornell LII), so what a page leaves out can count as much as what it says.

What should you do with the sheet?

Take it to a lawyer who handles FDA matters, before you change anything. The sheet is the record that conversation needs: every sentence, where it appears, what sits beside each product, and what each platform says. Bring all three tabs and the dates.

Do not treat the yes rows as a list of words to delete. The letters asked their recipients for "the specific steps you have taken to correct any violations" and for "an explanation of each step being taken to prevent the recurrence of violations" (FDA), which is a question about the business, not about wording. If your store has received a letter, our guide on how to respond to an FDA warning letter walks through what the letters ask for. For labels, see how to label a peptide vial.

Your self check scorecard

FAQ

Does a research use only label protect a peptide store?

The three letters we read say it did not settle the question for those stores. Each one quoted the seller's disclaimer and then said "evidence obtained from your website establishes that your products are intended to be drugs for human use" (FDA). Whether that applies to your store is a question for a lawyer.

Where does FDA define intended use?

In 21 CFR 201.128, which says the words "refer to the objective intent of the persons legally responsible for the labeling of an article (or their representatives)" (eCFR).

Does FDA only look at the product page?

No. The regulation names "labeling claims, advertising matter, or oral or written statements", and the letters introduce their evidence as "product labeling, including on your website" (FDA).

Can products sold alongside a peptide matter?

The NuScience and Peptide Partners letters both named a bacteriostatic water or reconstitution solution sold "to be used to reconstitute the peptide products sold on your website" (FDA).

Do Stripe or PayPal mention research chemicals?

Stripe's prohibited list includes "Incorrectly labeled research chemicals" (Stripe). The PayPal page we captured does not use the word research. Neither page names peptides.

How long did FDA give the stores to respond?

The Gram letter set "fifteen working days" and the two August letters set "fifteen (15) business days of receipt of this letter" (FDA).

Glossary

• Intended use: in 21 CFR 201.128, "the objective intent of the persons legally responsible for the labeling of an article (or their representatives)".
• Labeling: the label and the written, printed or graphic matter that goes with a product; the letters treated website text as product labeling.
• Unapproved new drug: the term each letter applied to the products it named, under section 505(a) of the FD&C Act.
• Research use only (RUO): a label statement that a product is for research. The three letters quoted RUO wording and still found intended use from the website.
• Representatives: people who speak for the seller, such as staff, affiliates and support agents, named in 21 CFR 201.128.
• Sentence sheet: the record this guide builds, one row per published sentence, with product, channel, address and date.

Key facts

• FDA's 2026 letters to 3 peptide sellers each say "evidence obtained from your website establishes that your products are intended to be drugs for human use" (FDA).
• 21 CFR 201.128 says intent "may be shown by such persons' expressions, the design or composition of the article, or by the circumstances surrounding the distribution of the article" (eCFR).
• The letters were dated March 31, 2026 (Gram Peptides) and August 24, 2026 (NuScience Peptides LLC and Peptide Partners LLC).
• Two letters named a bacteriostatic water or reconstitution solution sold beside the peptides (FDA).
• Stripe prohibits "Incorrectly labeled research chemicals" (Stripe).
• On October 26, 2026, the word "peptide" appeared 0 times on the eBay, Square, Stripe, PayPal and Braintree policy pages we captured, and once on Amazon's.

This guide covers business operations for store owners and gives no medical guidance. It is not legal advice; for your own business, ask a lawyer who handles FDA matters.

Sources

• eCFR: 21 CFR 201.128
• Cornell LII: 21 U.S.C. 321
• Cornell LII: 15 U.S.C. 52
• Cornell LII: 15 U.S.C. 55
• FDA: warning letter to Gram Peptides, March 31, 2026
• FDA: warning letter to NuScience Peptides LLC, August 24, 2026
• FDA: warning letter to Peptide Partners LLC, August 24, 2026
• Amazon Seller Central: Drugs and drug paraphernalia
• eBay: Prescription and over-the-counter drugs policy
• Stripe: Prohibited and restricted businesses
• Square: Payment Terms
• PayPal: Acceptable Use Policy
• Braintree: Acceptable Use Policy

Sources checked October 26, 2026.