What is Retatrutide?
Retatrutide (also known by its research designation LY3437943) is a 39-amino-acid synthetic peptide engineered as a triple incretin/glucagon receptor agonist — simultaneously targeting the GLP-1 receptor, GIP receptor, and glucagon receptor. This tri-agonism differentiates retatrutide from tirzepatide (dual GIP/GLP-1) and from first-generation GLP-1 selective agonists such as semaglutide.
The addition of glucagon receptor co-agonism is of particular research interest because glucagon receptor activation drives hepatic glucose production and increases energy expenditure through thermogenic mechanisms. When combined with the insulinotropic and satiety effects of GLP-1 and GIP co-agonism, the compound presents a multifaceted metabolic signalling profile of significant interest in preclinical metabolic research.
Like tirzepatide, retatrutide incorporates a C20 fatty acid modification for extended half-life via albumin binding, making it suitable for once-weekly dosing regimens studied in clinical research programmes. ClaraScience supplies retatrutide in 10mg lyophilised vials with ≥99.1% HPLC-verified purity and a full COA with every batch. For laboratory research use only.
Mechanism. Triple GLP-1/GIP/glucagon receptor agonist — adds energy expenditure and hepatic glucose modulation signals absent from dual agonists.
Structure. 39 amino acids, C20 fatty acid modification for extended half-life.
Stage. Phase II clinical data published. Not approved for therapeutic use anywhere.
Research Background
The Phase II clinical trial of retatrutide in adults with obesity was published in the New England Journal of Medicine by Jastreboff et al. in 2023. The study enrolled 338 participants across dose escalation arms ranging from 1mg to 12mg weekly subcutaneous injection over 24 weeks. At the highest dose group (12mg), mean bodyweight reduction reached approximately 17.5% — notable given the shorter 24-week duration compared to the 72-week SURMOUNT trials for tirzepatide.
Mechanistically, the addition of glucagon receptor agonism in retatrutide is theorised to contribute additional energy expenditure signals beyond GLP-1 and GIP pathways alone. Glucagon receptor activation has been studied for its role in hepatic lipid metabolism and brown adipose tissue thermogenesis in preclinical models, providing a distinct mechanistic contribution compared to dual GIP/GLP-1 agents.
Retatrutide represents the current frontier of triple incretin receptor research, making it a valuable compound for comparative mechanistic studies alongside tirzepatide and other metabolic peptides. Preclinical and in-vitro receptor binding studies continue to investigate the nuanced effects of triple agonism across metabolic tissue compartments.
Key citation Jastreboff AM et al. "Triple–Hormone-Receptor Agonist Retatrutide for Obesity." N Engl J Med. 2023;389(6):514–526.
Compound Specifications
| Common Name |
Retatrutide (LY3437943) |
| Structure |
39 amino acids · C20 fatty acid modification |
| Molecular Weight |
4813.45 g/mol |
| Receptor Targets |
GLP-1R + GIPR + Glucagon R (triple agonist) |
| Purity (HPLC) |
≥99.0% (99.21% verified this batch) |
| Vial Size |
10mg lyophilised powder |
| Storage |
2–8°C (short-term) · −20°C (long-term) |
| Primary Reference |
Jastreboff et al., N Engl J Med 2023;389:514–526 |
Storage & Handling
- Unopened vial: 2–8°C for regular use; −20°C for storage beyond 3 months.
- Reconstituted: 2–8°C, use within 28 days. No freeze-thaw after reconstitution.
- Reconstitution: Use sterile bacteriostatic water. Free reconstitution calculator available.
Full protocols in our Storage & Handling Guide.
Ordering & Pricing — Australia
| Quantity |
Price per vial |
Saving |
| 1–4 vials |
$159.95 AUD |
— |
| 5–9 vials |
$144.95 AUD |
Save 9% |
| 10+ vials |
$134.95 AUD |
Save 16% |
Free priority tracked shipping on orders over $250 AUD. 24-hour dispatch. Limited stock — contact us for bulk enquiries.
Frequently Asked Questions
What is retatrutide?
Retatrutide is a triple GLP-1/GIP/glucagon receptor agonist. It is a 39-amino-acid synthetic peptide with a C20 fatty acid modification, studied in Phase II clinical trials for metabolic research. All ClaraScience products are for laboratory research use only.
What is the difference between retatrutide and tirzepatide?
Tirzepatide targets GLP-1 and GIP receptors (dual agonist). Retatrutide adds glucagon receptor agonism for a triple-receptor mechanism, adding energy expenditure and hepatic metabolic signals to the incretin effects. Retatrutide is at an earlier clinical stage than tirzepatide.
Is retatrutide FDA or TGA approved?
No. Retatrutide has not been approved by the FDA, TGA, or any other regulatory authority for therapeutic use as of the time of writing. It is a Phase II research compound. ClaraScience supplies it strictly for preclinical laboratory research use only.
Is retatrutide available in Australia?
ClaraScience stocks retatrutide in our Australian warehouse. Orders are dispatched within 24 hours. Research use only. Not approved by the TGA.
What purity is your retatrutide?
≥99.1% HPLC-verified at a WHO/GMP-certified third-party laboratory. Full COA with chromatogram and mass spectrometry identity confirmation included with every order.
