Retatrutide 20mg / 30mg / 40mg
Metabolic
Overview
Retatrutide (LY-3437943) is an investigational triple-receptor agonist that combines activity at the GLP-1, GIP and glucagon receptors in a single 39-residue peptide backbone. Supplied as a sterile lyophilised powder in 20mg, 30mg and 40mg vials, each batch is verified to ≥98% purity by RP-HPLC and mass spectrometry.
Classification: Retatrutide (LY3437943) — a synthetic 39 amino-acid triple-agonist peptide with a C20 fatty-diacid moiety, engineered to activate three incretin/glucagon-family receptors in a single molecule.
Research background
Retatrutide is used in vitro to study the combined pharmacology of incretin (GLP-1, GIP) and glucagon receptor signalling in a single molecule. Research groups compare it head-to-head against dual agonists (e.g. Tirzepatide) to characterise receptor bias, cAMP response, and peptide stability across long incubation windows.
This summary describes published preclinical and, where applicable, clinical research. It is not a medical claim and does not describe or endorse any human use of the compound as sold by Peptides UK 4U.
Mechanism of action (under investigation)
Published research characterises retatrutide as an agonist at the GLP-1 receptor, the GIP receptor and the glucagon receptor. Preclinical and early clinical studies investigate the metabolic signalling consequences of simultaneous activation of all three pathways — a mechanism not shared by single- or dual-agonist analogues.
Laboratory handling
Reconstitute with bacteriostatic water in a sterile environment; the fatty-acid modification gives Retatrutide a long in-solution stability profile relative to native GLP-1. Prepare working aliquots to minimise freeze-thaw cycles.
Storage & stability
- Lyophilised vials: store below -18°C, protected from light.
- Reconstituted solution: refrigerate at 2–8°C and use within 30 days.
- Avoid repeated freeze-thaw cycles to preserve peptide integrity.
For reconstitution volumes and target working concentrations use our peptide calculator. We do not publish dosing protocols for human use.
Product specifications
- Peptide Type
- Triple receptor agonist (GLP-1 / GIP / Glucagon)
- Sequence length
- 39 amino acids
- Molecular weight
- ≈4,731 Da
- Form
- Lyophilised powder
- Quantity
- 20mg, 30mg or 40mg per vial
- Purity
- ≥98% by RP-HPLC + MS
- Solubility
- Water / bacteriostatic water
- Research code
- LY-3437943
Certificate of Analysis: Batch-specific COA available. View COAs.
Frequently asked questions
How does Retatrutide differ from Tirzepatide in research?
Retatrutide activates three receptors (GLP-1, GIP and glucagon), whereas Tirzepatide is a dual GLP-1 / GIP agonist. The added glucagon-receptor activity is the main mechanistic axis researchers compare in vitro.
What is the reported half-life of Retatrutide?
Published Phase 1/2 pharmacokinetic data reports a half-life of approximately 6 days, which is why research protocols use once-weekly administration.
What purity is your Retatrutide?
Every vial is tested to ≥98% purity by RP-HPLC and confirmed by mass spectrometry (~4,731 Da). A batch-specific Certificate of Analysis is published on our COA page.
How is Retatrutide reconstituted?
Reconstitute with bacteriostatic water in a sterile laboratory environment. For target concentrations and volumes across the 20/30/40mg vials, use our peptide calculator.
How stable is reconstituted Retatrutide?
The fatty-acid side chain gives Retatrutide good in-solution stability. Kept refrigerated at 2–8°C and protected from light, working solutions remain suitable for research use for up to ~30 days. Avoid repeated freeze-thaw cycles.
Do you ship Retatrutide from the UK?
Yes — all Retatrutide vials are UK-stocked with next-working-day dispatch on orders placed before 2pm.
Do you supply a Certificate of Analysis?
Yes — every batch has a third-party HPLC + MS COA linked from the product page.
References
- Coskun T et al., Cell Metabolism 34(9):1234–1247 (2022) — LY3437943 discovery and preclinical
- Jastreboff AM et al., NEJM 389(6):514–526 (2023) — retatrutide phase 2 obesity study
- Rosenstock J et al., The Lancet 402(10401):529–544 (2023) — retatrutide phase 2 type 2 diabetes
References are provided for educational context. Citation does not imply endorsement of any specific use.
Disclaimer: This article is provided for laboratory and educational purposes only. It is not medical advice and does not describe or endorse any human use. All products sold by Peptides UK 4U are for laboratory research only, are not for human or veterinary consumption, and are not intended to diagnose, treat, cure or prevent any disease.