Metabolic · Lyophilized Powder
Retatrutide Research Peptide - 10mg Vial
CAS: 2381089-83-2 | Sequence: 39-aa triple GIP/GLP-1/GCG agonist | Purity: ≥99.1%
129.99 / vial
Pre-Order - First Batch in Final QC
- Cold Storage −20 °C lyophilized
- Reconstituted 2–8 °C · 28 days
- HPLC ≥99.1% third-party verified
SKU PT-RETA-10 · HPLC + MS tested every batch · Insulated cold-pack shipping
What Is Retatrutide?
Retatrutide (LY3437943) is a 39-residue synthetic peptide (4731.33 g/mol) engineered to activate three receptors at once: the glucose-dependent insulinotropic polypeptide (GIP) receptor, the GLP-1 receptor and the glucagon receptor. It is the most studied of the so-called triple agonists, and it is used in metabolic research as a tool for separating the contributions of each pathway.
Its design follows the same logic as tirzepatide but adds a third arm. Aib residues at positions 2 and 20 and an α-methyl-leucine at position 13 resist enzymatic cleavage, while a C20 fatty diacid attached to Lys17 through a γGlu–AEEA linker binds albumin reversibly and extends the half-life to a multi-day range.
Supplied as 10 mg of white lyophilized powder at ≥99% HPLC purity with a batch-specific third-party COA. The first production batch is in final QC; request the full analytical package below and we will send it as soon as the certificate is released.
Request the Full HPLC Report
The first production batch of Retatrutide is in final QC. Ask for the complete HPLC and mass-spec package and we will email it the moment the certificate is released.
For laboratory research use only. We do not provide dosing guidance or medical advice.
Retatrutide Scientific Documentation
Technical reference data and a summary of published preclinical literature, provided for educational purposes.
| Name | Retatrutide (LY3437943) |
|---|---|
| Synonyms | LY3437943, LY-3437943 |
| CAS Number | 2381089-83-2 |
| Molecular Formula | C221H342N46O68 |
| Molecular Weight | 4731.33 g/mol |
| Sequence (3-letter) | Tyr-Aib-Gln-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-αMeLeu-Leu-Asp-Lys-Lys(γGlu-AEEA-C20 diacid)-Ala-Gln-Aib-Ala-Phe-Ile-Glu-Tyr-Leu-Leu-Glu-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2 |
| Sequence (1-letter) | Y(Aib)QGTFTSDYSI(αMeLeu)LDKK(γGlu-AEEA-C20 diacid)AQ(Aib)AFIEYLLEGGPSSGAPPPS-NH2Sequence compiled from supplier structural data and cross-checked against the published cryo-EM study. Confirm the exact string and the 4731.33 vs 4732.09 mass against your batch COA. |
| Structure Class | 39-residue linear peptide with Aib at positions 2 and 20, α-methyl-leucine at position 13 and a C20 fatty diacid on Lys17 via a γGlu–AEEA linker; C-terminal amide |
| Form | White lyophilized powder |
| Purity | ≥99.1% (RP-HPLC); identity confirmed by LC-MS |
| Content per Vial | 10 mg net peptide |
| Solubility | Soluble in water and bacteriostatic water; solubility is reduced under acidic conditions |
| Storage Conditions | Lyophilized: −20 °C, desiccated and protected from light. Reconstituted: 2–8 °C, use within 28 days. |
Triple Receptor Agonism
Retatrutide is a single peptide that activates three receptors — GIP, GLP-1 and glucagon (GCGR). One published review reports full agonism at all three, with EC50 values in the low-nanomolar to picomolar range and the highest potency at the GIP receptor. There is no “GLP-3” receptor; retatrutide's third target is the glucagon receptor.
Why the Glucagon Arm Matters
Commentary attributes the additional weight change seen with triple agonism, relative to dual GIP/GLP-1 agonists, to glucagon-receptor engagement and its reported effect on energy expenditure. Mouse data support this interpretation; the human mechanistic evidence remains limited.
Structural Basis
A 2024 cryo-EM study resolved retatrutide bound to all three receptors, describing how the Aib substitutions and the lipidated Lys17 side chain accommodate three distinct binding pockets. The C20 diacid provides reversible albumin binding and a multi-day half-life.
Clinical Programme Context
A 2023 phase 2 trial in the New England Journal of Medicine reported dose-dependent body-weight reduction, and Eli Lilly subsequently announced topline phase 3 results from TRIUMPH-1. Sources disagree on the current regulatory stage, and none of this is a therapeutic claim for the research material on this page.
Limitations
Published potency figures differ between sources — one review gives a GIP EC50 of 0.0037 nM while vendor data sheets report roughly 0.0643 nM. Treat any single reported value as provisional and verify identity and purity against the batch certificate.
Representative literature: Coskun T et al., Cell Metab 2022; Jastreboff AM et al., N Engl J Med 2023;389:514-526; Doggrell SA, Expert Opin Investig Drugs 2023; structural analysis in Nat Commun 2024 (PMC11255275).
Bacteriostatic Water Ratio Chart (10 mg Vial)
| Diluent Added | Concentration | Per 0.1 mL Aliquot |
|---|---|---|
| 1.0 mL | 10.0 mg/mL | 1 mg |
| 2.0 mL | 5.0 mg/mL | 500 µg |
| 2.5 mL | 4.0 mg/mL | 400 µg |
| 3.0 mL | 3.33 mg/mL | 333 µg |
| 5.0 mL | 2.0 mg/mL | 200 µg |
Reconstitution Procedure
Allow the vial to reach room temperature. Introduce sterile or bacteriostatic water slowly down the inner glass wall — do not inject directly onto the powder cake. Swirl gently until fully dissolved; do not shake or vortex, as this can promote aggregation.
Temperature Stability
| State | Condition | Typical Stability |
|---|---|---|
| Lyophilized | −20 °C, desiccated | 24+ months |
| Lyophilized | 2–8 °C | Up to 12 months |
| Lyophilized | Room temp (≤25 °C) | Several weeks (transit) |
| Reconstituted | 2–8 °C | Up to 28 days |
| Reconstituted | −20 °C aliquots | Avoid repeated freeze–thaw |
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