GLP-3-RT

GLP-3-RT is our catalog designation for research-grade retatrutide, a synthetic 39-amino-acid peptide supplied as a lyophilized powder for laboratory research use only. Every lot is independently assayed by Janoshik Analytical and the Certificate of Analysis is published before the lot is listed.

Compound overview

Retatrutide is a triple incretin receptor agonist. A single molecule engages three distinct receptor targets: the glucose-dependent insulinotropic polypeptide (GIP) receptor, the glucagon-like peptide-1 (GLP-1) receptor, and the glucagon (GCG) receptor. This makes it structurally and pharmacologically distinct from both single-target agonists such as semaglutide and dual agonists such as tirzepatide.

The addition of glucagon receptor agonism is what separates retatrutide from earlier incretin compounds. Glucagon receptor engagement introduces a signaling axis absent from GLP-1 and GIP activity alone, which is why retatrutide appears in research specifically designed to dissect the contribution of each receptor arm. The peptide carries modifications conferring resistance to dipeptidyl peptidase-4 (DPP-4) degradation, along with fatty acid acylation promoting reversible albumin binding and extended circulating half-life in published pharmacokinetic models.

Research context

As the most recently characterized of the major incretin agonists, retatrutide is used in comparative receptor pharmacology to separate GIP-mediated, GLP-1-mediated, and glucagon-mediated signaling within a single chemical scaffold. Published work examines cAMP accumulation across all three receptor populations, relative potency at each target, beta-arrestin recruitment, and receptor internalization kinetics.

Researchers frequently run retatrutide alongside tirzepatide and semaglutide to build a comparative series across single, dual, and triple agonism. For background reading, see our articles on dual GIP/GLP-1 receptor agonism and GLP-1 receptor signaling.

This material is supplied strictly as a research chemical for qualified investigators working in a controlled laboratory setting. It is not a drug, not a dietary supplement, and is not intended for diagnostic, therapeutic, or human use of any kind.

Analytical verification

Every lot is tested by Janoshik Analytical, an independent third-party laboratory, before it is offered for sale. Testing covers identity and purity by HPLC, with mass spectrometry confirming molecular weight against the expected value for the retatrutide sequence.

Because retatrutide is newer and less widely characterized than other incretin compounds, independent verification matters more here, not less. The lot number on your vial label corresponds to a specific Certificate of Analysis in our COA Library, and we publish the complete report rather than a headline purity number. Our guide on how to actually read a Janoshik COA covers what to check and where weak reports break down.

Specifications

• Compound: Retatrutide (catalog designation GLP-3-RT)
• Form: Lyophilized powder, sealed vial
• Receptor targets: GIP, GLP-1, and glucagon receptors (triple agonist)
• Molecular weight: approximately 4731 g/mol
• Purity: See the published COA for the specific lot
• Testing: HPLC and MS by Janoshik Analytical
• Available sizes: 20mg per vial

Handling and storage

Store lyophilized material sealed and protected from light. Short-term storage at 2 to 8 degrees Celsius suits vials in active use; long-term storage at -20 degrees Celsius or below preserves stability over extended periods. Allow sealed vials to equilibrate to room temperature before opening, since condensation introduces moisture that accelerates degradation.

Repeated freeze-thaw cycling is the most common avoidable cause of degradation in laboratory handling. Aliquoting reconstituted material into single-use volumes avoids subjecting the full quantity to repeated temperature transitions. Bacteriostatic water is stocked for laboratories requiring reconstitution diluent.

For laboratory research use only. Not for human or veterinary consumption. Not for diagnostic or therapeutic use.