What is retatrutide?
Retatrutide is a synthetic peptide studied in research as a triple receptor agonist with activity at the glucose-dependent insulinotropic polypeptide (GIP) receptor, the glucagon-like peptide-1 (GLP-1) receptor, and the glucagon (GCG) receptor. It is catalogued under CAS number 2381089-83-2 with a molecular formula of C₂₂₁H₃₄₂N₄₆O₆₈ and a molecular weight of 4731.33 g/mol. The compound is supplied as a lyophilized powder for laboratory research and is intended solely for research purposes, not for human use.
Within metabolic peptide research, retatrutide is frequently grouped with the incretin-based compound class because of its GLP-1 receptor activity. What distinguishes it is the simultaneous engagement of three receptors rather than one. This triple-agonist profile is the central reason retatrutide is studied as a distinct compound rather than as a variant of earlier single-target or dual-target peptides.
What is the molecular structure of retatrutide?
Retatrutide is a single-chain synthetic peptide with a molecular weight of 4731.33 g/mol and the molecular formula C₂₂₁H₃₄₂N₄₆O₆₈. Like other long-acting incretin-class research peptides, its structure incorporates a fatty-acid moiety attached to the peptide backbone. This lipidation is the structural feature most associated with extended circulating stability in published pharmacokinetic research, because the attached fatty acid promotes reversible binding to serum albumin and slows clearance in model systems.
The peptide is produced through solid-phase peptide synthesis followed by purification, and the research-grade material is characterized to a purity specification of 99.3% or higher by HPLC. The lyophilized form is a white to off-white powder. As with all peptides in this class, the structural integrity of the lipidation and the peptide chain is sensitive to temperature, which is why storage conditions matter for research reproducibility.
What receptors does retatrutide target?
Published research characterizes retatrutide as an agonist at three distinct receptors: the GIP receptor, the GLP-1 receptor, and the glucagon receptor. Each of these is a class B G-protein-coupled receptor involved in metabolic signaling. The GIP and GLP-1 receptors are incretin receptors, while the glucagon receptor sits in a counter-regulatory role within metabolic pathways.
The research interest in a single molecule that engages all three receptors comes from the way these pathways interact. GLP-1 and GIP receptor signaling are studied together in the incretin literature, and the addition of glucagon receptor activity introduces a third axis of metabolic signaling within the same compound. Research on retatrutide is focused on characterizing the balance of activity across these three receptors and how that balance compares with single-target and dual-target peptides studied in the same models.
How does retatrutide differ from GLP-1 receptor agonists?
The defining difference is the number of receptors engaged. A GLP-1 receptor agonist acts at a single receptor, a dual agonist engages two, and retatrutide is studied as a triple agonist across the GIP, GLP-1, and glucagon receptors. This places it at the more complex end of the incretin-class research spectrum.
| Property | GLP-1 receptor agonist | Retatrutide (GLP-3) |
|---|---|---|
| Receptor targets | GLP-1 receptor | GIP + GLP-1 + glucagon receptors |
| Class | Single-target incretin | Triple receptor agonist |
| Research framing | Single-pathway metabolic signaling | Multi-pathway metabolic signaling |
| Structural stability feature | Lipidation (varies by compound) | Lipidation for extended stability |
For a broader overview of the single-target end of this spectrum, see our article on GLP-1 receptor agonists. The comparison matters in research design because the multi-receptor profile means retatrutide cannot be treated as interchangeable with single-target peptides when interpreting results.
What does published research describe about retatrutide's mechanisms?
Published research describes retatrutide's mechanism in terms of concurrent agonism at the three receptors and the downstream signaling each engages. Activation of the GLP-1 and GIP receptors is studied in the context of incretin signaling pathways, while glucagon receptor agonism is studied for its effects on separate metabolic signaling axes. The compound is investigated for how simultaneous engagement of these receptors influences signaling in preclinical and in vitro models.
Because retatrutide is a research compound, the literature frames these mechanisms at the level of receptor pharmacology and cellular signaling rather than clinical outcomes. Research characterizes the relative potency of the compound at each of the three receptors, since the ratio of activity across GIP, GLP-1, and glucagon receptors is a defining variable for this compound class. Amino Foundry does not make any therapeutic or outcome claims regarding retatrutide; it is studied solely for its effects on these metabolic receptor pathways in research settings.
What is known about retatrutide's stability and handling in research?
Retatrutide is supplied as a lyophilized powder and is stored at −20°C to preserve structural integrity. As a lipidated peptide, it is sensitive to repeated temperature fluctuation, oxidation, and moisture. Research handling practices that preserve reproducibility include maintaining cold storage, minimizing freeze-thaw exposure, and protecting the lyophilized material from humidity.
Cold-chain handling during shipping is relevant for the same reason. A compound characterized at high purity at the point of manufacture can lose that specification if exposed to elevated temperatures in transit. For a deeper discussion of how temperature affects peptide integrity, see our guide on cold-chain shipping. This article does not provide reconstitution or preparation instructions; handling protocols are determined by the researcher according to their experimental requirements and applicable regulations.
How does Amino Foundry source retatrutide?
Amino Foundry supplies retatrutide as a research-grade compound held to a minimum purity specification of 99.3% or higher by HPLC, with mass spectrometry identity confirmation. Every order ships with a batch-specific Certificate of Analysis, and all shipments are cold-chain packaged as standard to protect the lipidated peptide structure in transit. For guidance on interpreting analytical documentation, see our article on how to read a Certificate of Analysis.
Researchers can review specifications, available sizes, and pricing on the product page for GLP-3 (retatrutide), or browse the full catalog of research compounds at all compounds. All material is intended for laboratory research use only.
This compound is a research chemical intended for laboratory and scientific research purposes only. It is not a drug, supplement, or food, and is not intended to diagnose, treat, cure, or prevent any disease. Amino Foundry does not sell products intended for human consumption. Researchers are responsible for compliance with all applicable local, state, and federal regulations.