Retatrutide is a synthetic triple receptor agonist with activity at the glucagon-like peptide-1 receptor (GLP-1R), the glucose-dependent insulinotropic polypeptide receptor (GIPR) and the glucagon receptor (GCGR). It is an investigational compound, is not approved by the FDA for any use, and appears in the literature under the development designation LY3437943.
Structurally it is a 39-amino-acid GIP-analog backbone carrying a fatty-diacid side chain, engineered so that a single ligand reaches all three receptors. It is the current reference construct for asking what glucagon-receptor agonism contributes on top of a dual-incretin profile.
Vantage lists this compound under the catalog name VA-3R. The catalog
name and the vial label use the short form; the compound is retatrutide, and this page is the
reference record for it.
A note on the catalog name. The Vantage short form is VA-3R, where the numeral denotes the third entry in the incretin line. There is no GLP-3 receptor; the designation is a catalog convention, not a pharmacological one. Retatrutide’s receptor profile is GLP-1R, GIPR and GCGR.
Verified dataVerified compound data
| Property | Value |
|---|---|
| Compound name | Retatrutide |
| Catalog name | VA-3R |
| CAS number | No CAS registry number is published for this compound in PubChem. Vantage does not list a registry number it cannot source to a primary registry. |
| PubChem CID | 171390338 |
| Molecular formula | C221H342N46O68 |
| Molecular weight | ~4731 g/mol |
| Length | 39 residues |
| Physical form | Lyophilized powder, or pre-formulated solution in a sealed research pen |
Molecular formula, molecular weight and registry data verified against PubChem
(CID 171390338).
Research-context mechanism
Preclinical characterisation of retatrutide focuses on the balance between its three receptor activities and on what the added GCGR arm changes in hepatic and energy-substrate research models relative to a dual GLP-1R/GIPR construct in the same system. Reported potency is not equal across the three receptors, and quantifying that imbalance is itself a live question in the receptor-pharmacology literature.
These mechanisms are described strictly as they appear in in vitro and animal research
models. They are not established human-use mechanisms, and nothing on this page describes an
approved therapeutic use, an outcome, or a protocol.
Current research summary
- Triple GLP-1R / GIPR / GCGR co-agonism and relative potency at each receptor
- Glucagon receptor biology within combination-agonist systems
- Hepatocyte and hepatic substrate-handling research models
- Lipid oxidation and energy-substrate models in animal systems
- Comparative incretin pharmacology: mono- versus dual- versus triple-agonist constructs
- Structure-activity work on multi-receptor peptide engineering
How identity and purity are verified
Every lyophilized lot Vantage publishes carries a batch Certificate of Analysis on its own
product page, showing the HPLC purity result and the mass-spectrometry identity result for
that specific lot. The certificate is issued by the manufacturer’s contract laboratory.
Vantage describes it as a batch COA and makes no claim of buyer-contracted independent
testing.
Purity publishes at the site specification of 98% or greater by HPLC. Mass-spectrometry
identity is reported against the compound’s own theoretical mass, which for retatrutide is
approximately 4731 g/mol as listed in the table above. Where a lot has no certificate on
file, no certificate is shown and no testing claim is made for it.
The certificate for the current lot is published on the product page:
VA-3R, 10mg lyophilized vial. The pre-formulated research pen is a
separate listing at VA-3R Pen; pens are supplied as a
sealed pre-formulated solution and do not carry a lot certificate.
Frequently Asked Questions
What is retatrutide?
Retatrutide is a synthetic 39-amino-acid peptide that acts as a triple agonist at the GLP-1, GIP and glucagon receptors. It is an investigational compound studied in preclinical receptor-pharmacology models, is supplied as a lyophilized powder, and is not approved for human use.
What is the molecular formula of retatrutide?
The molecular formula of retatrutide is C221H342N46O68, with a molecular weight of approximately 4731 g/mol (PubChem CID 171390338).
What is the CAS number for retatrutide?
PubChem publishes no CAS registry number for retatrutide. Vantage does not list a registry number it cannot source to a primary registry, so no CAS is shown for this compound.
Is VA-3R the same compound as retatrutide?
Yes. VA-3R is the Vantage catalog name for retatrutide. The catalog name and the vial label use the short form; the compound supplied is retatrutide, and its identity is confirmed on the batch Certificate of Analysis for each lot.
Is retatrutide approved for human use?
No. Retatrutide is not supplied as an approved drug and is not intended for human consumption. It is offered strictly as a research compound for laboratory use.
Does each retatrutide lot come with a COA?
Yes. Every lyophilized lot carries a batch Certificate of Analysis published on its product page, reporting HPLC purity and mass-spectrometry identity for that specific lot against the theoretical mass of approximately 4731 g/mol.
Related references
Vantage documents the other incretin-pathway compounds in its catalog at
semaglutide, tirzepatide and
retatrutide. All are listed under
incretin receptor agonists.
For research use only. Not for human or veterinary use. Not approved by the FDA. 21+
- HPLC + MS tested, on tested lots
- U.S. synthesized
- Batch COA on the pages that carry one