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Retatrutide Pen

Retatrutide Pen at a glance

Peptide.Express Retatrutide Pen (CAS 2381089-83-2) starts at $249, ≥99% HPLC as the sourcing specification — not a measurement of any one vial — with a molecular weight of 4731 Da and molecular formula C221H342N46O68; measured purity and mass are only on that lot’s Certificate of Analysis you can verify before purchase. Same-day dispatch on business days (orders before 2 PM EST), free over $150. For in-vitro laboratory research use only.

Retatrutide Pen — research-grade lyophilized peptide vial from Peptide.Express, ≥99% HPLC sourcing specification

30mg presentation shown.
Packaging reference.

Research-Grade Compound

The Retatrutide Pen is a prefilled dual-chamber research pen. Its cartridge holds lyophilized retatrutide (LY3437943; CAS 2381089-83-2; molecular weight 4,731 Da) in the upper chamber and bacteriostatic water, called bac water, in the lower chamber, and it is supplied in 15 mg and 30 mg strengths. Twisting the cartridge into the pen body combines the two chambers, so the peptide dissolves in preloaded diluent with no separate vial, syringe or diluent calculation. For in-vitro laboratory research use only. Not for human or veterinary use.

For laboratory research use only. Not for human or veterinary use.

Purity standard: Retatrutide Pen is sourced to ≥99% by HPLC — sourcing spec.

$249.00$299.00ListUSD / vial
1. Select sizeAmount per vial
1
US fulfillmentSame-day dispatch before 2 PM Eastern.
Free US shipping over $150Shipping options and processing times
Batch documentationView the selected batch report

For laboratory research use only. Not for human or veterinary use.

Batch documentation

Certificate of Analysis

Your batch. Independently tested.

Measured results, batch identifiers, and the original laboratory report for your selected presentation.

30mg

The batch behind your vial.

Peptide.Express research material packaging illustration. Neutral unlabeled vial.Packaging illustration
Peptide.Express
Batch record summary
LOT / BATCH
PX-L916
COA ACCESSION
2609220031
Reported HPLC purity99.98%

Result for the selected batch.

Selected presentation
30mg
Laboratory
Freedom Diagnostics
View original CoA

Batch details

Sourcing specification
≥99% by HPLC
Accession / CoA
2609220031
Test Date
September 22, 2026
Laboratory
Freedom Diagnostics
Lot
PX-L916
Purity (measured)
99.98%
Net content
31.62 mg
Reported
2026-09-22
HPLCLC-MS/MS

Issued by an independent third-party laboratory; Peptide.Express does not test in-house. Results are reproduced as-is and confirm compound identity, purity, and the analytical methods used.

Verify with testing laboratoryhow to read a CoA
How to match your vial to this report
  1. 1.Match the presentationRetatrutide Pen · 30mg selected.
  2. 2.Match the batchMatch lot PX-L916 to your vial.
  3. 3.Open the original CoAAccession 2609220031. Review the original methods and results.
Explore the lab-results library

Continue exploring

Explore related compounds

Illustrative Peptide.Express Retatrutide vial beside research notes. Decorative research-library photograph.

Retatrutide

The same peptide supplied as lyophilized vials, where the operator sets the diluent volume.

Illustrative Peptide.Express Tirzepatide vial and packaging.

Tirzepatide

A dual GIPR / GLP-1R agonist. Two receptors on one backbone rather than three.

Explore Bacteriostatic WaterExplore MOTS-c

Retatrutide Pen price per mg

Retatrutide Pen sizes, single-vial and pack prices, price per mg, lot number, measured HPLC purity and Certificate of Analysis link
Size1-vial pricePack prices$/mgLot #Measured HPLC %CoA
15mg$179.00—$11.93Pending CoAPending CoAPending CoA
30mg$249.00—$8.30PX-L91699.98%CoA PDFVerify at lab

$/mg is the single-vial price divided by the labeled mg per vial. Lot and measured HPLC are listed only when that size's own Certificate of Analysis is on file. All certificates are in the lab results index. For laboratory research use only.

Product information

Retatrutide Pen Specifications

Visit the research library
Compound specifications
Compound
Retatrutide
CAS
2381089-83-2
Molecular formula
C221H342N46O68
Molecular weight
4,731 Da
Purity
≥99% HPLC specification
Sequence
View published sequence

YAQGTFTSDYSILLDKKAQAAFIEYLLEGGPSSGAPPPS (39 residues; Aib 2 and 20, alpha-Me-Leu 13, C20 diacid on Lys17, C-terminal amide)

Research context

Retatrutide Pen (CAS 2381089-83-2) is studied in in-vitro and animal models via Triple GLP-1R / GIPR / GCGR Agonist in a Prefilled Dual-Chamber Pen…. This section covers the composition and analytical specification data. Analytical standard: ≥99% by HPLC. Stocked material is for laboratory research use only.

Related research guide: what is Retatrutide? →Retatrutide vs tirzepatide receptor comparison

Reconstituting Retatrutide Pen: step-by-step peptide reconstitution guide. Concentration maths: peptide reconstitution calculator.

Research reference

Retatrutide Pen research reference

One compound. Three research targets.

Research examines activity at GIP, GLP-1, and glucagon receptors. Explore the compound's mechanism and comparative research below.

Learn more about peptide pens: how dual-chamber research pens work
Retatrutide Pen receptor targetsA conceptual diagram connecting Retatrutide Pen to GIPR, GLP-1R, GCGR. Not a molecular structure or potency comparison.GIPRGLP-1RGCGRRETATRUTIDE PENLY3437943Triple-receptor agonist researchConceptual schematic · not to scale
Peptide.ExpressRESEARCH REFERENCE
Receptor pharmacology

Published research examines Retatrutide Pen activity at GIP, GLP-1, and glucagon receptors.

Learn more about peptide pens: how dual-chamber research pens workRelated research guide: what is Retatrutide? →
Comparative research
Retatrutide vs tirzepatide receptor comparison
Related research guide: what is Retatrutide? →Compound identity, mechanism, and research contextRetatrutide vs tirzepatide receptor comparisonCompare receptor researchPeptide pen guide: how dual-chamber research pens workLaboratory handling and methods

The research library

A closer look at the science.

Explore Retatrutide Pen's identity, receptor activity, and published research.

Explore the research
Peptide.Express research material packaging illustration. Neutral unlabeled vial.

Before you order

Buying Retatrutide Pen — Frequently Asked Questions

What purity standard applies to the Retatrutide Pen?

The sourcing specification is ≥99% by reverse-phase HPLC, with LC-MS/MS confirming mass against 4,731 Da. That is a specification the material is procured against, not a measurement of the pen in your hand. The measured figure for a lot is on its Certificate of Analysis.

Where is the Certificate of Analysis for the Retatrutide Pen?

In the certificate panel on this page for the strength you select, and in the Peptide.Express lab results library. Read the lot, accession, measured HPLC and testing laboratory from that panel, because they are printed on the certificate. A Certificate of Analysis is a batch record, so match the lot on the carton to the lot on the document.

What testing does the Retatrutide Pen material go through?

Where a certificate is on file it shows the assays that laboratory reported, which can include reverse-phase HPLC for purity, LC-MS/MS for mass identity and an endotoxin result. A line missing from a certificate is not a pass and is not proof the assay was never run. No sterility result is published for the pen presentation.

How should the Retatrutide Pen be stored?

Before mixing, store the sealed pen as printed on the carton label. After the chambers are combined, treat the contents as a reconstituted solution: 2 to 8 °C, protected from light, inside a short working window (the window published for reconstituted retatrutide is 14 to 28 days). Do not freeze the mixed solution.

When do research-peptide orders ship?

US orders placed before 2 PM Eastern ship the same business day. Orders over $150 ship free inside the US. See the shipping page for the current policy. For laboratory research use only. Not for human or veterinary use.

Is the Retatrutide Pen intended for human or veterinary use?

No. The Retatrutide Pen is sold for in-vitro laboratory research only. Nothing on this page describes or implies a use in people or animals, a dose, or a health benefit, and the pen format does not change that status.

Is the Retatrutide Pen FDA approved?

No. Retatrutide is not approved by the FDA or by any other regulator for any indication, and the pen is research-grade material, not a drug product. It is not manufactured under pharmaceutical GMP. For in-vitro laboratory research use only. Not for human or veterinary use.

All products are sold for in vitro laboratory research use only. Not intended for human consumption, clinical use, or veterinary use. Peptide.Express makes no medical claims. Consult the published literature for research application guidance.

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Catalog identity reference

Theoretical identity from the catalog or verified registry record — not a laboratory observation from the Certificate of Analysis above.

CAS Number
2381089-83-2
Molecular Formula
C221H342N46O68
Molecular Weight
4731 g/mol
Sequence
YAQGTFTSDYSILLDKKAQAAFIEYLLEGGPSSGAPPPS (39 residues; Aib at 2 and 20, alpha-Me-Leu at 13, C20 fatty diacid on Lys17 via gamma-Glu/AEEA linker, C-terminal amide)

What we can show you the numbers for

AOD 10MG and KPV 10MG vials