Triple-Agonist Metabolic Research Peptide
Retatrutide, development code LY3437943, is a synthetic 39-residue triple agonist peptide developed to target the GIP, GLP-1 and glucagon receptors simultaneously. Supplied as lyophilised powder for laboratory research and studied in receptor pharmacology and metabolic research models. Independently tested by Janoshik Analytical — the batch reports for 10mg (PLB-003) and 20mg (PLB-002) are on our Lab Reports page.
59.99
Inc. VAT · Free UK delivery over £75
Janoshik Analytical · 10mg: 99.515% purity, 13.51mg measured · 20mg: 99.763% purity, 18.36mg measured
About Retatrutide
Retatrutide is a synthetic 39-residue peptide engineered as a triple hormone receptor agonist, simultaneously activating the glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1) and glucagon receptors. Published research literature refers to it by its Eli Lilly development code, LY3437943, or by the name retatrutide. Pureline lists it under the internal product code RT1.
The published research on retatrutide, including the limits of what it shows and its investigational status, is reviewed on our Retatrutide compound profile. Retatrutide is not authorised as a medicine in the United Kingdom.
All Pureline Biolabs retatrutide is supplied as a lyophilised powder in sealed vials.
Product Specifications
| Compound | Retatrutide |
| Research name | Retatrutide |
| Classification | Triple agonist (GIP/GLP-1/Glucagon) |
| Amino acids | 39 |
| Molecular formula | C221H342N46O68 |
| Molecular weight | 4731.42 g/mol |
| CAS number | 2381089-83-2 (free peptide) |
| PubChem CID | 171390338 — listed on PubChem under the development name “Triple G” |
| Vial sizes | 10mg / 20mg nominal, lyophilised powder |
| Measured content | 10mg vial: 13.51mg · 20mg vial: 18.36mg |
| Purity | 10mg: 99.515% · 20mg: 99.763% — Janoshik verified |
| Form | Lyophilised powder, sealed vial |
| Batch | 10mg: PLB-003, Janoshik task #226521 · 20mg: PLB-002, task #226522 |
| Research use only | Not for human consumption |
Research Background
Retatrutide (LY3437943) has been studied in receptor pharmacology and metabolic research. The areas below describe what studies measured, not established effects. For the full evidence review, see the Retatrutide compound profile. This product is supplied for laboratory research purposes only.
Animal studies have measured energy expenditure and thermogenesis markers.
Rodent diet-induced obesity models have used fat mass and lean mass measurements as endpoints.
Studies have measured glucose tolerance and insulin signalling markers.
Animal studies have measured food intake and hypothalamic signalling markers.
Studies have measured the contribution of glucagon-receptor activity within the triple-agonist mechanism.
Studies have compared receptor activity against single- and dual-agonist incretin peptides.
Store in refrigerator. Keep away from direct light and heat sources.
Use within 28 days. Do not refreeze once reconstituted.
Stable for up to 24 months when frozen as lyophilised powder.
Standard refrigerator storage conditions are sufficient. Protect from prolonged direct light.
Reconstitution Guide
Retatrutide is supplied as a lyophilised powder and must be reconstituted with bacteriostatic water before use in research applications.
Allow vial to reach room temperature. Clean the rubber stopper with an alcohol swab and allow to dry completely.
Draw required volume of BAC water into a sterile syringe. Inject slowly down the inside of the vial wall — not directly onto the powder.
Gently swirl until powder fully dissolves. Do not shake. Solution should be clear and colourless.
Use our Reconstitution Calculator → for exact volumes.
Customer Reviews
1 review for Retatrutide 10mg / 20mg UK
Buying Retatrutide in the UK — common questions
Is “reta” the same thing as retatrutide?
Yes. Reta and reta peptide are the shorthand the research market uses; LY3437943 is Eli Lilly’s development code from the clinical programme. All three refer to the same 39-residue triple agonist. What they do not refer to is a pre-filled pen — Pureline supplies lyophilised powder in sealed vials for laboratory research, and anything sold as a ready-to-use “reta pen” is a different kind of product altogether. For the regulatory position and the published trial data, see Can you buy retatrutide in the UK?
How much retatrutide is actually in the vial?
More than the label says. Janoshik measured 13.51mg in the 10mg vial (batch PLB-003, task #226521) and 18.36mg in the 20mg vial (batch PLB-002, task #226522). Vial masses are nominal fill targets, so the measured figure on the certificate is the number to calculate from, not the label.
What purity is Pureline’s retatrutide, and who tested it?
99.515% for the 10mg batch and 99.763% for the 20mg batch, both by HPLC at Janoshik Analytical, with LC-MS supporting the assigned molecular identity. Those are area-percent figures under the laboratory’s stated method — they describe chromatographic purity of the tested sample, not biological activity.
How much bacteriostatic water does a retatrutide vial need?
That depends on the concentration the protocol calls for. Using the measured content: 2ml into the 10mg vial gives roughly 6.76 mg/ml, and 3ml into the 20mg vial gives roughly 6.12 mg/ml. Our reconstitution calculator has both batches loaded, and the reconstitution guide covers adsorption losses and aliquoting.
How should it be stored?
Sealed and lyophilised, keep it at 2–8°C and away from light; it ships cold chain from our UK facility. Once in solution, refrigerate at 2–8°C and aliquot into single-use portions before freezing, so the stock sees one freeze-thaw cycle rather than one per use. Let a closed vial reach room temperature before opening — lyophilised peptide is hygroscopic.
Can I see the Certificate of Analysis before I order?
Yes. Every batch report is published on our independent lab reports page before the stock is listed, and the batch number on the report matches the number printed on the vial you receive. Each label also carries a QR code that opens the report on Janoshik’s own verification server.
Is retatrutide legal to buy in the UK?
It is supplied strictly as a research chemical for in vitro laboratory use. Retatrutide holds no UK marketing authorisation and is not a licensed medicine here, so it is not sold for human or veterinary use and we do not supply it for that purpose. The UK peptide law guide sets out how research-use materials sit in the regulations.
What is the difference between the 10mg and 20mg vial?
Fill mass only — same compound, same synthesis route, separate batches and separate certificates. The 20mg vial works out cheaper per milligram than the 10mg, which matters if a protocol runs over several months; the 10mg is the smaller commitment for a single set of experiments.
All products sold by Pureline Biolabs Ltd are intended strictly for laboratory research purposes only. Not approved for human consumption, veterinary use, or any other application. Not evaluated by the MHRA or any other regulatory authority. Pureline Biolabs Ltd · Company No. 17236739 · purelinebiolabs.com
Lauren (verified owner) –
Great product. QR code on the label to see the testing