Description
Retatrutide (LY3437943) is an investigational 39-residue peptide from Eli Lilly that activates three receptors at once: GIP, GLP-1 and glucagon. Pure Peptides Canada supplies it only as a lyophilized laboratory reagent, in vials from 10 to 100 mg, with an independent Janoshik HPLC and mass-spectrometry report and tracked shipping from inside Canada. It is not an approved medicine and is not for human use.
Retatrutide at a glance
- What it is: a lipidated tri-agonist peptide acting at the GIP, GLP-1 and glucagon receptors, developed by Eli Lilly under the code LY3437943.
- What researchers study: receptor pharmacology across the three targets, comparisons with dual and single incretin agonists, and analytical methods for large lipidated peptides.
- Evidence level: cell, animal and controlled human trials, including the Phase 3 TRIUMPH programme. Still investigational.
- Regulatory status: not authorized in Canada, and named in Health Canada’s April 2026 public advisory on unauthorized injectable peptides.
- Supplied as: sealed lyophilized powder, 10, 20, 30, 60 or 100 mg, single vial or box of 10.
- Delivery: ships from inside Canada by tracked Xpresspost in 3–7 days ($25 CAD), or free in 4–12 days on orders over $299.
Regulatory status: retatrutide is an investigational compound. It is not authorized by Health Canada, and Health Canada’s April 2026 public advisory on unauthorized injectable peptides names it. We sell it strictly as a laboratory reagent for in-vitro research to qualified research buyers, and we do not provide dosing, administration or medical information.
Retatrutide
LY3437943 · GIP/GLP-1/glucagon receptor tri-agonist
- Y
- Aib
- Q
- G
- T
- F
- T
- S
- D
- Y
- S
- I
- αMeL
- L
- D
- K
- K
- A
- Q
- Aib
- A
- F
- I
- E
- Y
- L
- L
- E
- G
- G
- P
- S
- S
- G
- A
- P
- P
- P
- S
Blue: non-coded residues (Aib, 2-aminoisobutyric acid; αMeL, α-methyl-leucine). Outlined: lysine 17, which carries the fatty-acid side chain. The C-terminus is amidated.
- Length
- 39 amino acids, lipidated, C-terminal amide
- Molecular formula
- C221H342N46O68
- Molecular weight
- ≈ 4731.3 g/mol
- CAS number
- 2381089-83-2
- Developer code
- LY3437943 (Eli Lilly)
- Form
- Lyophilized powder, sealed vial
- Sizes
- 10, 20, 30, 60 or 100 mg (single or box of 10)
- SKU
- PP-RETATRUTIDE
Where the evidence stands
- Cell studies
- Animal models
- Controlled human trials
- Approved medicine
Phase 3 trials have reported results, but Eli Lilly still described retatrutide as investigational in September 2026. It is not an approved medicine in Canada.
What is retatrutide?
Most incretin-based compounds act on one or two receptors. Semaglutide targets the GLP-1 receptor; tirzepatide targets GIP and GLP-1. Retatrutide adds a third, the glucagon receptor, in a single peptide chain. Its sequence includes non-coded residues that resist enzymatic breakdown, and a fatty-acid side chain on lysine 17 lets it bind albumin in the blood, which greatly extends its circulating half-life.
Eli Lilly took retatrutide through a Phase 2 obesity trial published in The New England Journal of Medicine in 2023 and into the Phase 3 TRIUMPH programme, which began reporting results in 2026. Trial outcomes, with sources, are summarized in our retatrutide research guide. For laboratory work, the compound’s value is as a tool for separating what each of the three receptors contributes.
What retatrutide research looks at
- Receptor pharmacology: relative activity at GIP, GLP-1 and glucagon receptors, for example cAMP signalling in receptor-expressing cell lines.
- Class comparisons: tri-agonism versus the GLP-1/glucagon dual agonists mazdutide and survodutide.
- Glucagon-receptor biology: hepatic glucose output and energy-expenditure pathways.
- Analytical methods: HPLC and mass-spectrometry methods for large lipidated peptides, where identity data separates similar-sized molecules.
Ordering retatrutide for laboratory research
Check the report names retatrutide and shows a mass near 4731 Da.
See lab resultsRetatrutide FAQ
Where can I buy retatrutide in Canada?
Pure Peptides Canada supplies retatrutide only as a lyophilized laboratory reagent, in vials from 10 to 100 mg, shipped from inside Canada by tracked Xpresspost in 3–7 days ($25 CAD), or free in 4–12 days on orders over $299. It is not a Lilly product or a medicine, and it is not sold for human use.
Is retatrutide approved in Canada?
No. Retatrutide is investigational and is not authorized by Health Canada. Health Canada’s April 2026 public advisory on unauthorized injectable peptides names it.
How is retatrutide different from tirzepatide and semaglutide?
Semaglutide activates the GLP-1 receptor, tirzepatide activates GIP and GLP-1 receptors, and retatrutide activates GIP, GLP-1 and glucagon receptors. They are different molecules with different masses, which is why mass-spectrometry identity data matters.
How do I confirm the identity of a retatrutide batch?
Check that the mass-spectrometry result matches retatrutide’s theoretical mass, about 4731 Da for the free peptide, that the HPLC method suits lipidated peptides, and that the lot number matches your vial. Our COA guide and HPLC guide explain what to look for.
Can retatrutide be used in people or animals?
No. This product is for in-vitro laboratory research only and is not a drug, supplement or food. We do not provide dosing or administration information.
For laboratory research use only. Not a drug, supplement, food or cosmetic, not for human or veterinary use, and not intended to diagnose, treat, cure or prevent any disease.
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