910463-68-2
Most orderedSemaglutide
Acylated GLP-1 receptor agonist with a C18 diacid linker. The reference mono-agonist for incretin work.
Typical release99.4%
From
£44.00
In stock
Metabolic & IncretinMost ordered
Retatrutide
LY3437943 · GGG tri-agonist · Retatrutide peptide
Single-molecule agonist at the GIP, GLP-1 and glucagon receptors. Supplied lyophilised and released at ≥ 99.0% by RP-HPLC.
Total, ex VAT
£68.00
- Released at ≥ 99.0% (RP-HPLC, area %)
- Identity confirmed by ESI-MS against theoretical mass
- Batch certificate matched to the vial, verifiable online
- Same working day dispatch before 14:00, tracked
For laboratory research use only. Not for human or veterinary use, and not a medicine, food or cosmetic. Sold to qualified researchers and institutions who accept responsibility for safe handling and lawful use.
Compound data
What is in the vial
Indicative values for this line. The certificate issued with your batch is the authoritative record and reports the measured figures for the material you receive.
- CAS number
- 2381089-83-2
- Molecular formula
- C221H342N46O68
- Average mass
- 4731.33 g/mol
- Residues
- 39
- Class
- Incretin receptor tri-agonist (GIPR / GLP-1R / GCGR)
- Form as supplied
- Lyophilised powder, sealed under inert atmosphere
- Appearance
- White to off-white lyophilised cake
- Purity specification
- ≥ 99.0% (RP-HPLC, area %)
- Solubility
- Soluble in sterile or bacteriostatic water. Gentle swirling only — do not vortex or shake.
- Storage
- Lyophilised: −20 °C, desiccated and protected from light. Reconstituted: 2–8 °C.
Targets and pathways
- Glucose-dependent insulinotropic polypeptide receptor (GIPR)
- Glucagon-like peptide-1 receptor (GLP-1R)
- Glucagon receptor (GCGR)
Overview
About Retatrutide
Retatrutide, developed as LY3437943, is a synthetic 39-residue peptide engineered to act as a balanced agonist at three incretin and counter-regulatory receptors in one molecule: GIPR, GLP-1R and GCGR. It is the compound that established the tri-agonist as a distinct pharmacological class, and it is the reference molecule against which subsequent multi-agonists are characterised.
The design problem it solves is receptor balance. Adding glucagon receptor activity to a GLP-1 backbone raises energy expenditure but also raises hepatic glucose output; the residue substitutions and the C20 fatty diacid in retatrutide were selected to hold agonism at all three receptors within a window where the metabolic effects compose rather than cancel. That balance is what makes it useful as a research tool — it lets a single agent probe how the three pathways interact, instead of requiring three co-administered ligands.
For laboratory work, the practical consequence is that assay sensitivity to impurity is high. Related-substance peaks in a tri-agonist preparation can carry residual activity at one receptor and not the others, which skews selectivity ratios. Every Ryzen batch is released against a ≥ 99.0% area-percent specification by reversed-phase HPLC, with identity confirmed by electrospray mass spectrometry and the certificate matched to the vial.
In short
- Balanced tri-agonist at GIPR, GLP-1R and GCGR in a single 39-residue sequence
- C20 fatty diacid conjugation for extended plasma residence in preclinical models
- Released at ≥ 99.0% area-percent by RP-HPLC; identity confirmed by ESI-MS
- Lyophilised under inert atmosphere; certificate of analysis matched to batch
- Reference compound for multi-agonist selectivity and receptor-crosstalk studies
Where it is used
Research applications
Receptor crosstalk
Because all three receptor arms are engaged by one ligand, retatrutide is used to separate additive from interactive effects across the incretin and glucagon axes — work that co-administration of separate agonists cannot cleanly resolve.
Energy expenditure
Glucagon receptor agonism is the arm associated with increased energy expenditure and hepatic lipid oxidation. Retatrutide is used to study how that contribution scales relative to the appetite-side effects of GLP-1R engagement.
Glucose homeostasis
GIPR and GLP-1R agonism both act on glucose-dependent insulin secretion by distinct routes. The compound is used in beta-cell and islet preparations to characterise the combined secretory response.
Hepatic lipid handling
Preclinical and clinical substudies have examined liver fat fraction under tri-agonism, making retatrutide a common comparator in steatosis models.
Analytical method development
As a long, lipidated peptide it is a demanding analyte, and is frequently used as a system-suitability compound when developing RP-HPLC and LC-MS methods for modified peptides.
Handling
Reconstitution and stability
Reconstitution
Reconstitute with sterile or bacteriostatic water introduced slowly down the inner wall of the vial. Allow the cake to dissolve without agitation; swirl gently if needed. Do not vortex, invert vigorously or shake — mechanical stress promotes aggregation in lipidated peptides and shows up as new early-eluting peaks on re-assay.
Stability
As supplied and stored at −20 °C, desiccated and dark, the lyophilised powder is stable for at least 24 months. Once reconstituted, hold at 2–8 °C and use within 28 days. Avoid repeated freeze-thaw of the solution; aliquot at first reconstitution if the working programme requires more than a few withdrawals.
Notes
- Allow the vial to reach room temperature before opening — introducing solvent into a cold vial draws in moisture.
- Bacteriostatic water contains 0.9% benzyl alcohol and is the usual choice where a solution will be held for several weeks; sterile water is preferred where the diluent must not interfere with downstream assay.
- The lyophilised cake may sit as a thin film rather than a visible pellet. This is normal for low-fill vials and does not indicate short weight.
- Record the reconstitution date on the vial. Concentration drift from evaporation is the most common source of unexplained variance between runs.
Laboratory reference
Reconstitution calculator
Enter the fill weight on the vial and the diluent volume you intend to add. The calculator returns the resulting solution concentration and the volume that contains a given mass.
- Concentration
- 2.500 mg/mL · 2500 µg/mL
- Volume containing target mass
- 100.0 µL · 0.1000 mL
Figures are mass-to-volume arithmetic for laboratory preparation of Retatrutide and take no account of net peptide content, which is stated on the batch certificate and should be applied to the fill weight before calculating. Nothing here constitutes dosing, administration or clinical guidance of any kind.
Published work
What the literature reports
Summaries of published findings, provided as research reference. These describe work done by others in preclinical and clinical settings; they are not claims about this material or outcomes for any reader.
First-in-human characterisation
A phase 1 programme established the pharmacokinetic profile consistent with once-weekly exposure and reported dose-dependent reductions in body weight across ascending dose cohorts, alongside a predominantly gastrointestinal adverse-event profile.
Coskun et al., Cell Metabolism, 2022
Phase 2 obesity trial
In adults with obesity, 48 weeks of treatment produced a mean body-weight reduction of 24.2% at the highest dose studied, with a clear dose-response relationship across the arms.
Jastreboff et al., New England Journal of Medicine, 2023
Phase 2 type 2 diabetes trial
In adults with type 2 diabetes, treatment reduced HbA1c and body weight relative to comparator, supporting the hypothesis that glucagon receptor agonism can be added to incretin agonism without loss of glycaemic control.
Rosenstock et al., The Lancet, 2023
Hepatic steatosis substudy
A substudy of the phase 2 obesity programme reported reductions in liver fat fraction measured by MRI-PDFF, with the majority of participants reaching normal liver fat content by 48 weeks.
Sanyal et al., Nature Medicine, 2024
Questions
Retatrutide — asked and answered
Something not covered here? Ask us directly — technical questions reach someone who runs the assays.
- What purity does Ryzen release retatrutide at?
- Every batch is released at ≥ 99.0% area-percent by reversed-phase HPLC. The certificate of analysis for your specific batch reports the measured figure, the observed mass by ESI-MS against theoretical, water content by Karl Fischer, and appearance. Typical released purity across recent batches is 99.3–99.6%.
- How is identity confirmed?
- By electrospray ionisation mass spectrometry, comparing observed monoisotopic and average mass against the theoretical value for C221H342N46O68. RP-HPLC alone establishes purity but not identity, which is why both methods appear on every certificate.
- Which diluent should be used?
- Sterile water where the solution will be used promptly and the diluent must not interfere with downstream analysis; bacteriostatic water where the solution will be held for several weeks at 2–8 °C. Retatrutide is readily soluble in both. Avoid acidic diluents unless your protocol calls for them.
- Why does the vial look empty?
- Lyophilised peptide at low fill weights often forms a thin translucent film on the vial wall rather than a visible pellet. The fill is verified gravimetrically at packing. If you have any concern about a vial, quote the batch code and we will send the packing record.
- Can retatrutide be shipped outside the UK?
- Yes. We dispatch to research addresses across the EU and to selected other territories. Import rules are the buyer's responsibility, and we will supply the certificate of analysis and a commercial invoice describing the material accurately for customs.
- Is this material suitable for human use?
- No. It is supplied strictly for laboratory research and is not a medicine. It is not manufactured, tested or released to any standard that would support administration to humans or animals, and we sell only to researchers and institutions who accept that condition.
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Important
Retatrutide is supplied strictly for laboratory research and analytical use. It is not a medicine, food, cosmetic or veterinary product; it is not for human or animal consumption; and it is not intended to diagnose, treat, cure or prevent any condition. It is not manufactured, tested or released to any standard that would support administration to humans or animals. Information on this page is compiled for research reference and is not medical advice. No dosing, administration or therapeutic guidance is given or implied. By ordering you confirm you are a qualified researcher or institution and accept responsibility for safe handling and lawful use.