Peptide code names: what FDA quoted in August 2026

Does FDA recognise peptide code names?

Yes. Five FDA warning letters dated 24 August 2026 and posted 1 September quote the vendors' code names and identify the compound behind each one. Peak Performance Peptides' letter lists "'GLP-3R' (retatrutide)" among its unapproved new drugs. Tex Peptides' letter lists "Retatrutide (GLP-3 RT)", "Tirzepatide (GLP-2 TRZ)" and "Semaglutide (GLP-1 SEM)". FDA did not need the vendor to print the molecule's name; it read the product description and wrote the name in itself.

The numbering carries the whole scheme: GLP-1 is semaglutide, GLP-2 is tirzepatide, GLP-3 is retatrutide. The numbers count receptor targets loosely and are pharmacologically wrong. Tirzepatide has no GLP-2 activity, and Lilly calls "GLP-3" for retatrutide "a scientifically inaccurate label" (Lilly). The full retatrutide alias list is on our GLP-3 RT page.

What does GLP-2 TRZ mean?

It is tirzepatide. Tex Peptides sold it as "Tirzepatide (GLP-2 TRZ)"; Peptide Partners used "GLP-2 T" and NuScience "GLP-2 Tirz". All three appear in FDA's August letters.

What the letters cited instead of the name

None of the five letters turned on whether the vendor printed a drug's brand or generic name. They turned on three things a code name does not hide:

1. Product copy. FDA quoted descriptions such as Tex Peptides' "GLP-3 RT offers a unique and comprehensive approach to regulating glucose metabolism, energy balance, and weight management."
2. Bac water. Four letters list bacteriostatic water as a drug because "the sale of these products together demonstrates" it is meant for injection. The Royal letter raises it in a footnote.
3. Calculators. The Royal and NuScience letters cite a "peptide calculator" as a resource that provides "the means to prepare an injectable drug for human administration."

Lilly's 12 August complaint against Lone Star Peptide makes the same point from the civil side: it cites the seller's "Peptide Calculator" and a "step-by-step guide" to reconstitution (complaint, paragraphs 51 and 56). The case-by-case reading is in FDA's August 2026 peptide letters and Lilly's six lawsuits.

Code names still on sale

The scheme outlived the letters. On 5 October 2026 the Chameleon Peptides storefront, closed to new purchases, still showed "CP-3R" in up to 60 mg vials and "CP-2T" under "Metabolic Research", the same 1/2/3 numbering FDA had decoded six weeks earlier. A third-party directory, peptidedecode.com, reported on 3 October that Ascension Peptides sells GLP SKUs under code names. Ascension's homepage showed none when we checked the same week, and we have not confirmed those listings.

What we documented

In May 2026 we ran two parallel investigations that produced compatible findings.

Particle Peptides (particlepeptides.com) lists Retatrutide on the public catalog as GLP-3. The product page itself names the compound as "GLP-3 (LY3437943)" — LY3437943 is the chemical identifier Eli Lilly uses internally and on every clinical trial registration for Retatrutide. The mapping is unambiguous on Particle's own copy. There is no public note on the listing flagging the alias for buyers searching the term "Retatrutide."

Summit Biotech (summitbiotechusa.com) ships eight different FDA-cited compounds under coded SKU names. We captured the catalog through the Supabase API the storefront itself queries — the same endpoint the site's own JavaScript hits to populate the product grid. Forty in-stock products at capture time. The codenamed subset:

Source: Summit Biotech catalog ID fbb34a1e-e17b-4b7b-8d81-e44749337e8d lists Sema-1 at $50 / 10mg vial; ID cd49626e-6b5b-4089-8a2b-12cdb4da2cb8 lists R-10mg at $55 / 10mg. Both records carry Janoshik COA links (tests/93072 and tests/150000 respectively) whose filename slugs on the COA URL spell out the real compound — sema10mg_OZ101201 and RT10White_cap — even when the product display name does not.

In October 2026 we added a third shop. Amino Club (aminoclub.com), audited on 15 October 2026, sells the three GLP-1s as GLP-1 (SM), GLP-2 (TR) and GLP-3 (RT): semaglutide, tirzepatide and retatrutide. Its own lab records name the compound outright. ILS's record for lot RT0004 of "GLP-3 RT - 10mg" reports the identity as retatrutide, confirmed. We found no FDA letter naming the shop as of that date (full audit).

The identification of compound from coded name is not a guess. Each Summit Biotech SKU's COA URL contains the lab's filename for the sample, which is keyed on the actual molecule. R-10mg resolves to a Janoshik test for retatrutide. T - 30mg resolves to Tirzepatide_30mg_Orange_cap. The vendor has obscured the display name but not the COA URL.

CODED SKU NAME → ACTUAL COMPOUND (VIALAUDIT COHORT, MAY 2026)

● Coloured rows are FDA-cited GLP-1 / GIP / glucagon-receptor compounds named in 2024–2026 enforcement actions.

Why operators do this

Three motivations stack. They are not mutually exclusive — a vendor gets all three benefits from one rename.

1. Pharmaceutical-trademark evasion

Eli Lilly has trademarked Retatrutide-adjacent commercial names and holds patents covering the Retatrutide molecule under its LY3437943 identifier. Tirzepatide is sold by Lilly as Mounjaro and Zepbound; Semaglutide is sold by Novo Nordisk as Ozempic and Wegovy. A research-peptide catalog that prints "Tirzepatide" in the SKU display name is one search-and-seizure step from a cease-and-desist in any market where the compound is patent-protected. A catalog that prints "T - 30mg" is not — there is nothing trademarked about the letter T.

This is the same logic that drove the 2024 FDA warning letters collected in Foley & Lardner's December 2024 write-up: the agency targeted "GLP-1 providers" by their copy and SKU labels, not by the underlying chemistry. The codename pattern is a direct response — strip the copy of the cited terms and the warning-letter template no longer matches.

2. Google / Meta ad-keyword filter evasion

Google Ads and Meta Ads both maintain blocklists for prescription-only pharmaceutical names. "Tirzepatide", "Semaglutide", and (more recently) "Retatrutide" are flagged terms — campaigns containing them are auto-rejected or shadow-throttled. A catalog page titled T - 30mg passes the keyword filter at submission time. Whether the buyer can still find the product is a different question — most click-through arrives via SEO on the compound's actual name elsewhere on the site (blog posts, FAQ, COA filenames), or via brand-direct traffic.

This is the lowest-friction explanation. It does not require any regulatory awareness on the operator's part, just the experience of having had three Google Ads accounts disabled.

3. FDA-warning-letter risk diversification

The December 10, 2024 FDA warning letter to Summit Research Peptides (letter 695607) specifically cited Tirzepatide and Semaglutide by name on the vendor's website. The cited entity reorganized to summitbiotechusa.com afterwards — the version we audited — and the catalog's SKU labels no longer print those names. The display name is T - 30mg. The chemistry is unchanged. The next FDA reviewer parsing the catalog for trademarked compound names finds none.

We are not asserting motive on the operator's part. We are asserting the operational effect: the codename rebrand removes the pharmaceutical-trademark text from the surface a warning letter templates cites. Whether the rebrand was prompted by the prior letter or coincidental is impossible to determine without subpoena. The post-enforcement timing is the data point we have.

Per-mg pricing on Retatrutide across vendors

The four-vendor comparison below uses the actual catalog prices our price index captured in May 2026. The codename vendors are not materially cheaper than the named-listing vendors at the high end — but Summit Biotech's R-10mg is the cheapest Retatrutide per-mg in our entire seven-vendor index.

Note, 10 October 2026: Swiss Chems no longer lists retatrutide; the bar above is its May 2026 price. See our Swiss Chems audit.

The two coloured bars are the codename vendors. Particle's GLP-3 sits at the top of the per-mg curve; Summit Biotech's R-10mg sits at the bottom. The codename pattern correlates with neither above-market nor below-market pricing — it is independent of price positioning, which is consistent with the trademark-and-keyword-filter explanation rather than a predatory-pricing explanation.

How to detect coded catalogs as a buyer

Three checks, all reproducible without vendor cooperation.

Check the COA URL, not the product display name. The COA filename is keyed on the chemistry, not on the marketing label. If the SKU is called R-10mg but the COA URL is janoshik.com/tests/150000-RT10White_cap_…, the molecule is Retatrutide regardless of how the catalog presents it. This is the single highest-yield check — operators rebrand the SKU label but rarely rename the COA URL because the lab assigned the filename, not the vendor.

Search the product detail page for the chemical identifier. Many codenamed listings still print the chemical or research identifier inline — Particle's GLP-3 page literally writes "(LY3437943)" in the copy. Tirzepatide listings often print "LY3298176"; Semaglutide listings often print "NN9535" or "NN9924". A single grep for the identifier on the product page resolves the alias.

Compare the SKU mass / price ratio against the named market. If a codenamed SKU lines up suspiciously closely with the per-mg curve of a named compound on other vendors, the codename probably maps to that compound. A vendor selling R-10mg at $5.50/mg sits exactly in the Retatrutide pricing band; that is not random.

Single-vendor disclosures are useful but limited. We've documented hostname-aliasing as a separate evasion pattern — codename catalogs are the SKU-level analog. Both share the underlying incentive structure: operators reduce what a regulator's automated parser can match on, while leaving the chemistry visible enough to the buyer who knows what to search for.

Implications

The codename pattern matters for three audiences.

For buyers, the alias risk is informational asymmetry. A buyer searching for "Retatrutide" gets zero hits on Particle's catalog unless they happen to know about GLP-3. The buyer who knows the alias gets the cheapest Retatrutide per-mg in the market; the buyer who doesn't gets routed to a different vendor, or to nothing at all. The alias is functionally a discount available only to insiders.

For audit desks like vialaudit, codename catalogs make cross-vendor pricing comparisons harder. Our /peptides-index page matches catalog SKUs against a canonical compound list; codename-only listings require a manual mapping step that doesn't generalize. We've added Particle's GLP-3 to the Retatrutide canonical list explicitly. Summit Biotech's R-10mg, T-30mg, and Sema-1 are added as of this article, and we maintain the alias mapping by hand as new code names appear.

For regulators, the codename pattern is operational evidence that prior enforcement worked at the naming layer and not at the supply layer. The Summit Research Peptides → Summit Biotech rebrand removed Tirzepatide and Semaglutide from the catalog text but did not remove them from the warehouse. Future warning-letter templates will need to cite COA URLs and chemical identifiers, not just SKU display names, to bind the operator on the chemistry that is actually being shipped.

Sources

• Eli Lilly Retatrutide clinical trial registration: NCT04881760 — LY3437943 is the chemical identifier used on every Eli Lilly trial of the triple-agonist GLP-1 / GIP / glucagon-receptor compound.
• FDA Warning Letter, Summit Research Peptides (Dec 10, 2024): https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/summit-research-peptides-695607-12102024 — cites Tirzepatide and Semaglutide on the vendor's website by name; triggered the rebrand to summitbiotechusa.com.
• Foley & Lardner, "FDA Targets GLP-1 Providers with Warning Letters" (Dec 2024): https://www.foley.com/insights/publications/2024/12/fda-targets-glp-1-providers-with-warning-letters/ — context on the warning-letter template and the named-compound matching the agency uses.
• Particle Peptides GLP-3 product page: https://particlepeptides.com/en/buy-peptides/95-glp-3-10mg.html — the page itself reads "GLP-3 (LY3437943)" in the description copy.
• Summit Biotech catalog (authenticated capture, May 2026): product IDs fbb34a1e-e17b-4b7b-8d81-e44749337e8d (Sema-1), cd49626e-6b5b-4089-8a2b-12cdb4da2cb8 (R-10mg), 5c061fdc-7249-443d-927a-458925620613 (T - 30mg), d8a44912-37a0-4600-8f22-42495dbe61b1 (T - 60mg), c03ab27f-24f2-484e-9b40-aad9ac7d69ec (Cagri), c52f0bcd-f3f2-49ad-96d4-33854c0b354c (Tesa 20mg), 294bff3a-da55-4c3a-98fc-24ec66d00593 (**-31 - 10mg). Each record carries a Janoshik or Vanguard COA URL whose filename spells out the actual molecule.
• vialaudit audit notes, May 2026: Summit Biotech code-name table with prices, and the cross-vendor fingerprint scan behind this investigation.
• FDA warning letters dated 24 August 2026: Peak Performance Peptides 735127, Royal Peptides 734884, NuScience Peptides 733652, Peptide Partners 735063, Tex Peptides 735067
• Eli Lilly, What to know about retatrutide
• Eli Lilly v. Lone Star Peptide Co., S.D. Tex., complaint, filed 12 August 2026
• Chameleon Peptides storefront, read 5 October 2026
• Internal: Particle Peptides vendor profile — already documents the GLP-3 → Retatrutide alias as a transparency finding.
• Internal: How to spot a hostname-aliased peptide vendor — the hostname-level analog to the catalog-level pattern this piece documents.