Retatrutide
Retatrutide, also designated LY3437943, is a synthetic peptide described in the literature as a single molecule with agonist activity at three receptors: GLP-1, GIP and glucagon. It is an investigational compound in clinical development and is not an approved medicine. VaultLabs supplies retatrutide as a lyophilised reference material for in vitro laboratory research only.
Research use only. For in vitro research use only. Not for human or animal consumption. Not for human consumption, medical use, or personal application.
Reviewed by VaultLabs Research Editorial Desk · Last updated 2026-08-03
Key facts
- Development designation LY3437943; CAS registry number 2381089-83-2.
- Molecular formula C172H265N43O55; molecular weight 4113.64 g/mol — substantially larger than most catalog peptides.
- Described as a triple agonist acting at the GLP-1, GIP and glucagon receptors, distinguishing it from single- and dual-agonist incretin peptides.
- Investigational only: it is in clinical trials and has not been approved by the UAE Ministry of Health and Prevention, the FDA, the EMA or any comparable regulator.
- Its size makes analytical characterisation and handling more demanding than for a short peptide; LC-MS confirmation is particularly valuable for this material.
- Chemical name
- Retatrutide (LY3437943)
- Common synonyms
- LY3437943, GLP-1/GIP/glucagon triple receptor agonist peptide
- CAS number
- 2381089-83-2
- Molecular formula
- C172H265N43O55
- Molecular weight
- 4113.64 g/mol
- Appearance
- White to off-white lyophilised powder
- Catalog strengths
- 10 mg / 20 mg GLP-3 RT lyophilised vials
What retatrutide is
Retatrutide is a long synthetic peptide engineered so that a single sequence engages three related receptors — GLP-1, GIP and glucagon. That design places it in the incretin class alongside earlier single-target and dual-target peptides, but the three-receptor profile is what the published characterisation work focuses on.
At 4113.64 g/mol it is roughly three times the mass of BPC-157 and an order of magnitude larger than a copper tripeptide. Size has direct practical consequences: chromatographic methods developed for short peptides may not resolve it well, solubility behaviour differs, and the material is more sensitive to aggregation during handling.
It is supplied lyophilised. For a peptide of this length the dry state is not merely convenient but the only sensible way to ship and store material while preserving the certified specification.
Regulatory status — read this first
Retatrutide is investigational. It is being studied in clinical trials and has not been approved as a medicine by any major regulator, including the UAE Ministry of Health and Prevention. There is no approved indication, no approved product, and no legitimate route by which VaultLabs material could be used in a person.
This matters more for retatrutide than for most of the catalog because public interest in incretin peptides is high and misuse is a documented problem internationally. VaultLabs supplies this material strictly for in vitro laboratory research, accepts orders only against a research-use declaration, and retains that declaration in the order record.
Institutional purchasers remain responsible for their own approvals and internal controls. Because the compound is under active clinical investigation by its originator, laboratories should also consider intellectual-property and publication constraints relevant to their own work.
Where the research literature sits
The published literature on retatrutide is comparatively young and clustered around receptor pharmacology and clinical-trial reporting by the sponsor. In vitro work characterises binding and signalling at the three target receptors, typically in transfected cell systems using cyclic AMP or beta-arrestin readouts.
For a laboratory sourcing reference material, the relevant use cases are analytical rather than pharmacological: method development, reference standards for detection work, stability studies, and comparison against other incretin-class peptides. VaultLabs does not supply the material for the purpose of replicating clinical endpoints and makes no claims about metabolic outcomes.
Analytical characterisation and handling
Release is against an HPLC purity specification with the certificate tied to the lot number. For a peptide of this size, mass confirmation carries proportionally more weight than for short sequences, because deletion or truncation variants are more likely and harder to resolve chromatographically. Laboratories with LC-MS access should plan an incoming-goods confirmation.
Store sealed lyophilised vials at 2–8 °C, protected from light and moisture, and equilibrate to room temperature before opening. Reconstitute gently — vigorous agitation promotes aggregation in long peptides — and avoid repeated freeze-thaw cycling entirely where the protocol allows.
Record the diluent, reconstitution date and every thaw cycle. The certified purity describes the lyophilised material at release; the condition of a stored solution is determined by your handling and should be re-verified for long-running work.
How VaultLabs supplies retatrutide
Catalog presentations are GLP-3 RT 10 mg and GLP-3 RT 20 mg vials — same retatrutide compound family, independent lot numbers and certificates. Stock is held under controlled cold storage before dispatch across the UAE.
Because this compound attracts more consumer interest than most research materials, VaultLabs applies the same institutional checks here as elsewhere in the catalog and will decline orders that indicate an intended human use.
Research interest areas
Receptor binding assays
Glucose homeostasis models (preclinical)
Energy expenditure literature reviews
In vitro receptor pharmacology
Storage information
2–8 °C (lyophilized, sealed)
2–8 °C · protect from light. Use temperature-aware UAE dispatch and immediate laboratory storage on receipt.
Stability notes
Peptide agonists require strict cold chain and minimal exposure. Verify integrity via COA HPLC before long-term study incorporation.
In vitro molecular registry
Registry entry for Retatrutide (catalogued as GLP-3 RT). Specifications are resolved from the same source that generates the product page and the certificate of analysis.
| Chemical name | Retatrutide (GLP-3 RT / Reta) |
|---|---|
| CAS Registry Number | 2381089-83-2 |
| Molecular formula | C172H265N43O55 |
| Average molecular weight | 4113.64 g/mol |
| Synonyms | Reta, RETA (colloquial), LY3437943, triple GLP-1/GIP/glucagon receptor agonist peptide |
| Purity specification | 99.91% |
| Analytical method | HPLC |
| Appearance | White to off-white lyophilized powder |
| Product code | VL-GLP3-RT-10 |
| Regulatory status | For in vitro laboratory research use only — not for human or animal consumption |
Chain architecture
A large synthetic polypeptide substantially longer than the short reference peptides in this registry, prepared by solid-phase synthesis and supplied lyophilized. Its mass places it at the upper end of the range routinely handled by conventional reversed-phase methods, which in practice means a shallower organic gradient is required to achieve acceptable peak symmetry than would be used for a pentadecapeptide.
Historical characterisation and entry into the analytical literature
The molecule entered the published literature under the development designation LY3437943 as a single-molecule multi-receptor agonist framework, and is described in metabolic research literature as engaging three incretin and glucagon-family receptor pathways simultaneously rather than one. VaultLabs catalogues the material under the designation GLP-3 RT. Its analytical interest as a reference standard derives less from that pharmacological history than from its size: it is one of the few widely available synthetic polypeptides in this mass range, which makes it a useful upper-bound test article when a chromatographic or mass-spectrometric method must be demonstrated to perform across a wide molecular-weight span.
Receptor and pathway vectors reported in the literature
Pathways characterised in published preclinical and in vitro assay literature. No affinity constants are stated: values reported without their assay conditions are not comparable, and VaultLabs has not determined them independently.
- GLP-1 receptor pathway, as characterised in preclinical receptor-binding assay literature
- GIP receptor pathway, reported in the same multi-agonist assay context
- Glucagon receptor pathway, completing the triple-agonist framework described in the literature
- Comparative receptor-selectivity panels in in vitro screening reported for multi-agonist peptide frameworks
Use as an in vitro laboratory reference standard
- High-molecular-weight system-suitability standard demonstrating method performance across an extended mass range
- Test article for electrospray charge-state deconvolution workflows, where its broad, well-populated envelope exercises the algorithm
- Reference standard in preclinical receptor-binding assay development for multi-agonist frameworks
- Gradient-optimisation standard where retention of large polypeptides must be demonstrated
Chromatographic and spectrometric behaviour
Requires a shallower acetonitrile gradient than short peptides for acceptable peak shape, and is more sensitive to column temperature than low-mass standards. In electrospray it generates a broad multiply charged envelope spanning many consecutive charge states, which is diagnostically useful but demands adequate mass-analyser range and correct deconvolution parameters.
Stability profile
Larger polypeptides are markedly more susceptible to physical aggregation and to interfacial adsorption than short peptides. Reconstitute by directing diluent down the vial wall without agitation, inspect for haze before every use, and prepare low-concentration working dilutions in low-binding vessels immediately before use rather than storing them.
This registry entry describes analytical and preclinical in vitro laboratory context only. The material is an analytical reference material supplied strictly for in vitro laboratory research use only. It is not a medicine, food supplement or cosmetic, and it is not for human or animal consumption.
Selected literature
Named papers behind the statements on this page. Each entry resolves on PubMed and through its DOI, so you can read the source rather than take our summary of it. Inclusion describes the research record and is not a claim about this material’s suitability for any use.
Retatrutide — a game changer in obesity pharmacotherapy
Katsi V, et al. · Biomolecules · 2025
Review of the triple-agonist receptor pharmacology and the registered trial programme.
Emerging pharmacotherapies for obesity: a systematic review
Kokkorakis M, et al. · Pharmacological Reviews · 2025
Positions retatrutide against other incretin-class agents; useful for comparative receptor selectivity.
Databases and verification
Registry and database entries for independent identity checks. These are standing searches rather than fixed records, so they stay current as new work is indexed.
- CAS Common Chemistry — 2381089-83-2 — CAS
- PubChem record for retatrutide (LY3437943) — PubChem
- Indexed literature on retatrutide receptor pharmacology — PubMed
- Registered clinical studies of retatrutide — ClinicalTrials.gov