Reta, Retta, Retatrutide: Sorting Out the Shorthand
Search volume for "reta" and "reta peptides" has climbed faster than for retatrutide itself. All of it points at one molecule — LY3437943 — which this catalogue lists as GLP-3/RT. Here is how the names line up, and where each one is and is not accurate.
- "Reta", "retta peptides" and "reta peptides" are all community shorthand for retatrutide, the Eli Lilly investigational compound coded LY3437943.
- Retatrutide is a triple agonist: it engages the GIP, GLP-1 and glucagon receptors, where semaglutide engages one and tirzepatide two.
- This catalogue lists the research-grade compound as GLP-3/RT — the same molecule, under a catalogue name rather than a drug name.
- "Retta" with two t's is a misspelling that has become a real search term; it does not denote a different compound.
- Retatrutide holds no marketing authorisation from any regulator anywhere in the world, including Health Canada and the FDA.
- Material supplied here is for in vitro laboratory research use only — not for human or veterinary consumption.
Four search terms, one molecule
Over the past year the fastest-rising peptide searches in Canada have not been the formal chemical names. They have been abbreviations: **reta**, **reta peptides**, **retta peptides**. All three point at the same compound as the full name, **retatrutide**.
If you arrived on one of those searches, this is the mapping:
| What people type | What it refers to |
|---|---|
| reta | retatrutide, shortened the way "sema" shortens semaglutide and "tirz" shortens tirzepatide |
| reta peptides | the same compound, usually in a sourcing context |
| retta peptides | a common misspelling — one molecule, two t's |
| retatrutide | the International Nonproprietary Name |
| LY3437943 | the Eli Lilly development code used in the trial literature |
| GLP-3/RT | how this catalogue lists the research-grade compound |
None of these denote different molecules. There is no compound called "retta", and no separate product behind the abbreviation.
Why this catalogue says GLP-3/RT
Research suppliers in Canada operate under a straightforward constraint: a compound with no marketing authorisation cannot be presented as a medicine, and a catalogue that names investigational drug candidates as though they were products invites exactly that reading. Listing the compound as **GLP-3/RT** keeps the catalogue in research-supply language.
The molecule is unchanged. The certificate of analysis, the lot number and the LC-MS identity confirmation all refer to the same material the literature calls retatrutide.
What the compound actually is
Retatrutide is a synthetic, lipidated single-chain peptide that agonises three receptors at once:
- —**GIP receptor** — glucose-dependent insulinotropic polypeptide
- —**GLP-1 receptor** — glucagon-like peptide-1
- —**Glucagon receptor** — the counterintuitive one
That third arm is what distinguishes it. Semaglutide engages one of these receptors; tirzepatide engages two. The glucagon receptor is normally associated with raising blood glucose, but glucagon-receptor activity also increases energy expenditure and drives hepatic fat mobilisation, and the design premise was that two incretin arms could handle glycemic control while the glucagon arm raised energy burn.
Molecular weight of the research-grade material supplied here is 4759.5 g/mol.
Where the data stands
The Phase 3 TRIUMPH programme reported through 2026 and the numbers are covered in detail in our separate write-up: **Retatrutide in 2026: What the Phase 3 TRIUMPH Data Actually Showed**. That post carries the trial arms, the endpoint definitions and the adverse-event rates, and is the right place to look for figures rather than repeating a partial set here.
Two things are worth stating plainly on the naming question, because they are what the shorthand tends to obscure:
**It is not approved anywhere.** Retatrutide holds no marketing authorisation from Health Canada, the FDA, the EMA or the MHRA. It is an investigational compound. Any source presenting it as an approved or prescribable medicine is misrepresenting its status.
**Trial figures describe the trial.** The TRIUMPH results were produced under a clinical protocol with screening, titration, monitoring and a defined population. They are not transferable to any other setting, and nothing in that data set is a statement about material supplied for laboratory research.
What "reta peptides" usually means in a search
In practice the phrase is a sourcing query — someone looking for research-grade material and trying to work out which supplier to trust. The useful filter there is documentation rather than terminology:
- —Is there a **batch-specific certificate of analysis**, not a generic sample COA?
- —Was it tested by an **independent third-party lab**, not the seller?
- —Does the certificate report **both HPLC purity and LC-MS identity**? Purity alone tells you the vial is 99% *something*.
- —Can you **verify the lot number yourself**, without asking?
- —Does the supplier ship **domestically**, so there is no customs step?
Our own approach to each of those is set out in How We Test, and every published certificate is browsable at Lab Results.
Sourcing these compounds in Canada
Compounds referenced in this guide:
- —**GLP-3/RT** — the triple-agonist research compound, 10 mg, ≥99% purity
- —**GLP-2/Tirz** — the dual GIP/GLP-1 comparator
- —**Cagrilintide** — amylin-receptor agonist, a different mechanism entirely
These are supplied for laboratory research use and ship from within Canada — Vancouver, BC, typically 2 to 5 business days, tracked and insured. Every certificate is searchable by lot number. No customs risk, no USD conversion, free shipping over $300 CAD.
Frequently asked questions
Is "reta" the same as retatrutide?
Yes. "Reta" is community shorthand for retatrutide, the same way "sema" is used for semaglutide. It does not refer to a different compound or a different grade of material.
What about "retta peptides" with two t's?
A misspelling that has become a common search term. There is no compound called retta.
Why is it listed as GLP-3/RT and not retatrutide?
Because retatrutide is an investigational compound with no marketing authorisation, and a research catalogue should not present it in drug-name terms. The material and its certificate of analysis are unchanged.
Is retatrutide approved in Canada?
No. It is not approved by Health Canada, or by any other regulator, for any use.
Can I buy reta in Canada for research?
Popular Peptides supplies GLP-3/RT (10 mg) domestically from Vancouver, BC for in vitro laboratory research use only. It is not sold for human or veterinary consumption.
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GLP-3/RT is supplied for in vitro laboratory research use only. It is not approved by Health Canada for therapeutic use, is not a treatment for any condition, and is not intended for human or veterinary consumption. 18+.
Every batch we sell is independently third-party tested, with the full Certificate of Analysis published and checkable by lot number.