"For Research Use Only" Did Not Protect Them: The Exact Words FDA Quoted From Peptide Sellers in 2026

Two FDA warning letters dated 2026-08-24, to NuScience Peptides and Peptide Partners, each quote the seller's research only label statement and then cite 6 website quotes as evidence of intended use, 12 in total. Each letter also states a conclusion from the website evidence, quoted in full below. (REG-015, REG-026, REG-014, REG-025)

Updated October 28, 2026.

What did FDA say about research use only labels in 2026?

In the letters to NuScience and Peptide Partners, FDA quoted the seller's research label statement and cited website evidence. (REG-015, REG-026, REG-014, REG-025) In both letters FDA writes "Despite statements on your product labeling" before the quoted label wording. (REG-015, REG-026) The sources captured for this guide contain the full label wording for two letters: NuScience Peptides LLC and Peptide Partners LLC. (REG-015, REG-026) Compare the research wording on your own labels with the wording FDA quoted. (REG-015, REG-026)

What is the label statement versus what FDA said, letter by letter?

FDA's NuScience and Peptide Partners letters quote different research label statements. (REG-015, REG-026) The NuScience letter quotes "for laboratory, research, and analytical use" and "not intended for human or veterinary use," (REG-015) The Peptide Partners letter quotes "for research use only" and "not for human or veterinary use," (REG-026) Unlike the NuScience wording "for laboratory, research, and analytical use" (REG-015), the Peptide Partners wording is "for research use only" (REG-026). Each letter also states a conclusion from the website evidence, quoted in full in its own paragraph. (REG-014, REG-025) Compare your own label statements with the wording in the table.

The NuScience and Peptide Partners letters each state that the "evidence obtained from your website establishes that your products are intended to be drugs for human use" (sources: NuScience letter, Peptide Partners letter). (REG-014, REG-025) Unlike the label wordings, which differ (REG-015, REG-026), the conclusion sentences match (REG-014, REG-025). Compare the label statement and the conclusion in each row of the table.

How does the NuScience letter introduce its evidence?

FDA's NuScience letter gives "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". (REG-006) In plainer words, the examples come from the product labeling, and that includes the website. (REG-006) The letter refers to 21 CFR 201.128 for the definition of intended use. (REG-006) Compare what your website says with what your labeling says.

FDA's NuScience letter says the sale of its products together shows an intent for the water product "to be used in combination for injection". (REG-013) FDA also wrote: "The sale of these products together demonstrates that you intend for your “Bacteriostatic water for Peptides (BAC Water)” to be used in combination for injection." (REG-013) Source: NuScience Peptides warning letter. In plain words, FDA reads the sale of the products together as a sign of the intended use of the water product. (REG-013) Check how your own listings group products that are sold together.

What exact website language did FDA quote to NuScience?

FDA's NuScience letter quotes six passages that describe research, clinical trials and reported results. (REG-007, REG-008, REG-009, REG-010, REG-011, REG-012) Two of them refer to "clinical trials" and to "Preclinical studies in rodent models". (REG-009, REG-008) In plainer words, the quoted passages talk about studies and what they reported. (REG-008, REG-009, REG-010) Check each quotation against FDA's page before you reuse it.

In FDA's NuScience letter, the quoted copy describes a peptide as under exploration for research applications and cites preclinical studies in rodent models. (REG-007, REG-008) One passage reads: "is a novel investigational peptide being explored for its potential research applications in metabolic disorders, particularly obesity and type 2 diabetes". (REG-007) The other reads: "Preclinical studies in rodent models have demonstrated its efficacy in promoting weight loss and improving glycemic control." (REG-008) Source: NuScience Peptides warning letter. In plainer words, both are statements about research on a peptide, as FDA's letter quotes them. (REG-007, REG-008) Compare the wording on your own product pages with the passages quoted here.

The text quoted in FDA's NuScience letter says a peptide "has shown promising results in clinical trials" and "has been shown" to produce results. (REG-009, REG-010) One passage reads: "has shown promising results in clinical trials for weight management and metabolic disorders". (REG-009) The other reads: "has been shown to significantly reduce visceral adipose tissue and improve liver health by decreasing liver fat and preventing fibrosis progression" (REG-010) Source: NuScience Peptides warning letter. In plainer words, both are statements about results reported for a peptide, as FDA's letter quotes them. (REG-009, REG-010) Compare the wording on your own product pages with the passages quoted here.

The text quoted in FDA's NuScience letter names ipamorelin and cites "experimental research". (REG-011, REG-012) One passage reads: "[R]esearch has indicated that ipamorelin can counteract glucocorticoid-induced reductions in bone formation". (REG-011) The other reads: "experimental research exploring neural control of sexual function" (REG-012) Source: NuScience Peptides warning letter. In plainer words, both are statements about research, one of them naming the compound ipamorelin. (REG-011, REG-012) Compare the wording on your own product pages with the passages quoted here.

How does the NuScience letter conclude on intended use?

FDA wrote in its NuScience letter that the "evidence obtained from your website establishes that your products are intended to be drugs for human use". (REG-014) Source: NuScience Peptides warning letter. FDA states this conclusion in the same letter that quotes the research label statement. (REG-014, REG-015) In plain words, FDA says the evidence from the website shows what the products are intended for. (REG-014) Read the full sentence in the letter before comparing it with your own pages.

What exact website language did FDA quote to Peptide Partners?

FDA's Peptide Partners letter quotes six passages that describe possible benefits, scientific findings and how compounds work. (REG-018, REG-019, REG-020, REG-021, REG-022, REG-023) Two of them use the hedged words "could have" and "may help". (REG-018, REG-019) In plainer words, the quoted passages talk about findings and possible benefits. (REG-018, REG-019, REG-020, REG-021) Check each quotation against FDA's page before you reuse it.

The text quoted in FDA's Peptide Partners letter uses the hedged wording "could have" and "may help", and one passage names tirzepatide. (REG-018, REG-019) One passage reads: "could have potential benefits for bone health by promoting the generation of new bone tissue". (REG-018) The other reads: "may help explain why tirzepatide is effective in lowering blood sugar and reducing weight" (REG-019) Source: Peptide Partners warning letter. In plainer words, both are hedged statements as FDA's letter quotes them, and one of them names the compound tirzepatide. (REG-018, REG-019) Compare the wording on your own product pages with the passages quoted here.

The text quoted in FDA's Peptide Partners letter names Retatrutide and SS-31 and refers to scientific findings about them. (REG-020, REG-021) One passage reads: "Scientists have discovered how the weight-loss drug Retatrutide can also help treat a type of breast cancer". (REG-020) The other reads: "suggest[ing] that SS-31 could be a potential treatment to protect the retina" (REG-021) Source: Peptide Partners warning letter. In plainer words, both are statements about scientific findings on a named compound, as FDA's letter quotes them. (REG-020, REG-021) Compare the wording on your own product pages with the passages quoted here.

The text quoted in FDA's Peptide Partners letter names Tesamorelin in one passage and speaks of "understanding how the drug might work in the body" in the other. (REG-022, REG-023) One passage reads: "by which Tesamorelin improves liver health in this patient population". (REG-022) The other reads: "important for understanding how the drug might work in the body to affect sexual function" (REG-023) Source: Peptide Partners warning letter. In plainer words, both passages are statements about how a compound works, one of them naming Tesamorelin. (REG-022, REG-023) Compare the wording on your own product pages with the passages quoted here.

How does the Peptide Partners letter conclude and describe risk?

FDA wrote in its Peptide Partners letter that the "evidence obtained from your website establishes that your products are intended to be drugs for human use". (REG-025) Source: Peptide Partners warning letter. The same letter quotes the research label statement. (REG-026) Like the NuScience letter, this letter uses the same conclusion sentence. (REG-014, REG-025) In plain words, FDA says the evidence from the website shows what the products are intended for. (REG-025) Read the full sentence in the letter before comparing it with your own pages.

FDA wrote in its Peptide Partners letter that "injectable drug products can pose risks of serious harm to users". (REG-027) Source: Peptide Partners warning letter. In plain words, FDA says that drug products of the kind it names can pose risks to users. (REG-027) Read the full letter for the context of this sentence.

FDA's Peptide Partners letter also reads the sale of products together as a fact about the intended use of a water product. (REG-024) FDA wrote in the same letter: "The sale of these products together demonstrates that you intend for your “Reconstitution Solution (BAC)” to be used in combination for injection." (REG-024) Source: Peptide Partners warning letter. Like the NuScience letter (REG-013), this letter (REG-024) cites the sale of products together. Review how your own order pages describe products bought together.

Where does each quote appear?

FDA's NuScience letter quotes passages, a label statement and a conclusion, recorded as REG-007 to REG-012, REG-015 and REG-014. (REG-007, REG-008, REG-009, REG-010, REG-011, REG-012, REG-015, REG-014) FDA's Peptide Partners letter does the same, recorded as REG-018 to REG-023, REG-026 and REG-025. (REG-018, REG-019, REG-020, REG-021, REG-022, REG-023, REG-026, REG-025) Unlike the NuScience label statement "for laboratory, research, and analytical use" (REG-015), the Peptide Partners label statement reads "for research use only" (REG-026). Check a quote against its entry before you reuse it.

What FDA quoted in the two letters read in full

Which other letters mention research labeling?

The tool data summaries for NuScience, Gram Peptides and Prime Sciences each mention research labeling or research peptides. (OPS-004, OPS-010, OPS-013) These rows come from the tool's own summaries, not from the full letter text. (OPS-004, OPS-010, OPS-013) The NuScience summary says products labeled research peptides, the Gram Peptides summary says research use only labeling, and the Prime Sciences summary says products described as research peptides. (OPS-004, OPS-010, OPS-013) Compare the research wording in these summaries with the wording on your own listings.

The site's summary of FDA's Gram Peptides letter describes products sold "with research use only labeling", and its Prime Sciences summary describes products "described as research peptides". (OPS-010, OPS-013) Both summaries say FDA cited the products as unapproved new drugs. (OPS-010, OPS-013) In plainer words, the site's summaries record research wording for both sellers alongside FDA's citation. (OPS-010, OPS-013) The captured sources do not give the label statements FDA quoted in either letter. Read both letters on FDA's site before comparing their wording with yours.

What does 21 CFR 201.128 say about intended use?

The rule ties intended uses to the objective intent of the persons legally responsible for the labeling of an article, or their representatives. (REG-172) The NuScience letter points to 21 CFR 201.128 for the meaning of intended use. (REG-006) The rule lists ways intent may be shown, from expressions and labeling claims to the circumstances of distribution. (REG-003, REG-002, REG-173) In plainer words, the rule looks to what the responsible persons say and how the article is labeled, advertised and distributed. (REG-003, REG-002) Compare each row of the table with how your own pages and statements describe your products.

Does a label statement settle the question under that rule?

The rule text lists several ways to show intent. (REG-003, REG-002) It ties intent to the objective intent of the persons responsible for the labeling. (REG-172) It lists expressions, design, composition and the circumstances of distribution as ways intent may be shown, and labeling claims, advertising matter and statements as examples. (REG-003, REG-002) In the letters to NuScience and Peptide Partners, FDA quoted the label statement and cited website text. (REG-015, REG-026, REG-014, REG-025) The captured sources do not say how FDA weighs a label statement against website text under the rule.

What does this show and not show?

In the NuScience and Peptide Partners letters dated 2026-08-24, FDA quoted research style label statements and cited website language as evidence of intended use. (REG-015, REG-026, REG-014, REG-025) Both letters state the same conclusion about the website evidence. (REG-014, REG-025) In plainer words, each letter quotes a research style label statement and also cites website language. (REG-015, REG-026) Compare the label statement and the website language on your own pages with what each letter quotes.

Each conclusion sentence speaks of evidence from the recipient's website and the recipient's products. (REG-014, REG-025) The NuScience letter and the Peptide Partners letter use identical words for it. (REG-014, REG-025) The captured sources do not say that either letter makes a statement about any compound in general. The captured sources do not say how FDA would treat a seller whose website contains none of the language quoted above.

Which letters could the sources not read in full?

Nine of the 11 letters on the tool's list could not be read in full for this guide. (OPS-004, OPS-006, OPS-005, OPS-007, OPS-008, OPS-009, OPS-010, OPS-011, OPS-012, OPS-013, OPS-014) The NuScience and Peptide Partners letters were read in full. (OPS-004, OPS-006) The other nine are Peak Performance Peptides, Royal Peptides, Tex Peptides, Wholesale Peptide, Gram Peptides, Pink Pony Peptides, Mile High Compounds, Prime Sciences and Darmerica. (OPS-005, OPS-007, OPS-008, OPS-009, OPS-010, OPS-011, OPS-012, OPS-013, OPS-014) For those nine the guide has the tool data summaries and evidence quotes. (OPS-005, OPS-007, OPS-008, OPS-009, OPS-010, OPS-011, OPS-012, OPS-013, OPS-014) The captured sources do not give label statements or FDA's reasoning for those nine letters beyond the tool's summaries and evidence quotes.

FAQ

What label wording did FDA quote to NuScience Peptides?

"for laboratory, research, and analytical use" and "not intended for human or veterinary use". (REG-015)

What label wording did FDA quote to Peptide Partners?

"for research use only" and "not for human or veterinary use". (REG-026)

How many website quotes did FDA cite in each letter?

Six in the NuScience letter and six in the Peptide Partners letter. (REG-007, REG-008, REG-009, REG-010, REG-011, REG-012, REG-018, REG-019, REG-020, REG-021, REG-022, REG-023)

Which date do both letters carry?

Both are dated 2026-08-24 in peptideecommerce.com's tool data. (OPS-004, OPS-006)

Which rule defines intended use in these letters?

The NuScience letter refers to intended use as defined in 21 CFR 201.128. (REG-006)

Did the tool data record research labeling in any other letter?

Yes: the Gram Peptides entry mentions research use only labeling and the Prime Sciences entry mentions research peptides. (OPS-010, OPS-013)

Does a letter say a compound is illegal?

The captured sources do not say that. FDA's conclusion in each letter speaks of the seller's website and products. (REG-014, REG-025)

Is this legal advice?

No. This guide reports what the sources say. Talk to a licensed attorney for your situation.

Sources