Retatrutide
Retatrutide research peptide. Lyophilized powder, ≥99% purity by HPLC. For research use only.
About Retatrutide
What is Retatrutide (LY3437943)?
Retatrutide is an investigational peptide developed by Eli Lilly under the research code LY3437943. It is a single 39-amino-acid molecule that acts as an agonist at three receptors at once – GIP, GLP-1 and glucagon – which is why the scientific literature calls it a triple agonist or 'GGG' agonist.
Retatrutide is not an authorised medicine. Virexa Labs supplies it purely as a research peptide for in-vitro laboratory research – not for human or veterinary use.
Structure and mechanism of action
The peptide backbone is derived from the GIP sequence and carries a fatty-acid side chain. This lipidation lets the molecule bind to serum albumin, which slows its clearance: clinical studies reported a half-life of roughly six days. In vitro, the same albumin binding is worth keeping in mind when you choose assay media, because the protein content of the medium can shift the potency you measure.
- GLP-1 receptor – incretin signalling and insulin secretion in cell and animal models
- GIP receptor – incretin signalling and adipose-tissue metabolism
- Glucagon receptor – hepatic metabolism and energy expenditure
Research areas
Retatrutide is studied in models of energy balance, glucose homeostasis, hepatic lipid metabolism and receptor pharmacology. A recurring preclinical question is what the glucagon component adds on top of GIP/GLP-1 agonism, so retatrutide is often run side by side with the dual agonist tirzepatide (LY3298176) in receptor-signalling assays, such as cAMP readouts in receptor-expressing cell lines.
Phase 2 results were published in 2023 and a large phase 3 programme (TRIUMPH) is under way. Those clinical studies are run by the developer; the material sold here is a research reagent.
Handling, reconstitution and storage
Store the lyophilised vials at −20 °C, dry and protected from light; 2–8 °C is fine for short periods. Most labs reconstitute with bacteriostatic water: let the vial reach room temperature, add the solvent slowly along the inside wall and swirl gently until the powder has dissolved – don't shake. Keep the solution at 2–8 °C, use it within about four weeks and avoid repeated freeze–thaw cycles; dividing it into aliquots helps.
Want to buy Retatrutide for research? Every batch is tested by HPLC for ≥99% purity and by mass spectrometry for identity, and the batch COA is linked on this page.
Frequently asked questions
What is Retatrutide?
Retatrutide (LY3437943) is an investigational 39-amino-acid peptide that activates the GIP, GLP-1 and glucagon receptors. Virexa Labs supplies it as a lyophilised research peptide.
What is the difference between Retatrutide and Tirzepatide?
Tirzepatide is a dual GIP/GLP-1 receptor agonist; retatrutide also activates the glucagon receptor. Both are lipidated 39-amino-acid peptides developed by Eli Lilly.
What purity does your Retatrutide have?
≥99% by HPLC, with identity confirmed by mass spectrometry. The COA for each batch is shown on the product page.
How do I store Retatrutide?
Lyophilised: at −20 °C, dry and dark (2–8 °C for short periods). Reconstituted: at 2–8 °C, used within about four weeks, without repeated freeze–thaw cycles.
Is Retatrutide suitable for human use?
No. Our retatrutide is sold strictly for in-vitro laboratory research and is not intended for human or veterinary use.