Retatrutide peptide

01

Buying retatrutide from OXpeptides: three sizes, one report per size

The vial comes in 10 mg, 20 mg and 30 mg. In all three cases it holds a lyophilized powder in a crimp-sealed borosilicate glass vial, and each size was analysed on its own by Janoshik Analytical. The table gives the prices exactly as the cart computes them, per vial and per multi-vial order.

The cheapest size per milligram is the 30 mg vial: €6.50 per mg, against €8 for the 20 mg and €8.99 for the 10 mg. The gap comes from packaging. Filling, sealing, labelling and testing a vial costs about the same whatever amount of powder goes into it.

The multi-vial prices apply on their own in the cart, with no code, from 3 and then from 5 vials of the same size. Sizes are not mixed: three 10 mg vials and two 30 mg vials make two separate lines, each at its own rate.

Home delivery costs €9.90. It becomes free from €120 of products, after the multi-vial discount, which means a single 20 mg or 30 mg vial already ships free.

02

10, 20 or 30 mg: choosing the right size

The useful question is not "which size is best", it is "how many milligrams does my work need, and over how many sessions". Two cases come up again and again.

• A one-off need or a first series: the 10 mg vial (€89.90) saves opening a large vial to use only part of it and keeping the rest.
• A recurring need or a long series: the 30 mg vial (€194.90) or a multi-vial order. Three 10 mg vials hold as much material as one 30 mg vial, for €227.70 instead of €194.90.

In between, the 20 mg (€159.90) suits those who want headroom without moving to the large vial. In every case the molecule, the specification and the testing are the same. Only the amount of powder changes, and with it the analysis report, which is specific to each size.

03

Retatrutide price, cost by cost

Vials listed at a half or a third of this price can be found online. A fair comparison brings every offer back to the milligram, then looks at what was paid for behind that price.

• Synthesis. 39 amino acids plus a grafted fatty-acid chain make a long peptide that is hard to produce cleanly. Every extra coupling step lowers the yield.
• Independent testing. One report per size and per lot, ordered from a third-party laboratory and verifiable, is a fixed cost that sellers without reports do not carry.
• European logistics. Stock held inside the European Union and a tracked parcel avoid customs and the weeks of waiting for a parcel coming from Asia.

An offer far below the market has nearly always cut one of these costs. The most common cut is invisible on the photo: a vial holding less than its label states. That is why our reports give the measured amount, vial by vial, and not only the purity.

04

Retatrutide, reta, GLP-3, LY3437943: one peptide

In English the molecule goes by several names. They all mean the same compound.

• Retatrutide: the international non-proprietary name, the one on our label and on the Janoshik report.
• Reta, or "reta peptide": the usual short form in shops and on forums.
• LY3437943: the research code under which the molecule was first described in the literature.
• GLP-3: a trade nickname that refers to the three receptors involved. It is neither an official name nor a hormone that exists under that name.

Whatever name goes into the search box, what proves the identity of a powder is a laboratory measurement on that powder. The name a seller prints proves nothing. That is why every size sold here links to its own report, open for checking at the laboratory.

05

Identity and structure of the molecule

Retatrutide is a single peptide chain designed to bind three different receptors: the GIP receptor (GIPR), the receptor written GLP-1R and the glucagon receptor (GCGR). Hence the phrase "triple agonist". Earlier research compounds in this family targeted one or two of them. Bringing all three into one molecule is what sets it apart in the literature.

The fatty-acid chain grafted onto the sequence is a standard technique in peptide chemistry: it lets the molecule associate with albumin. For the lab, two practical consequences matter more. At over 4,700 g/mol it is a large amphiphilic molecule that is weighed on an analytical balance. And the lyophilized powder picks up moisture from the air, so an open vial must be kept dry.

06

What the literature described in vitro

The first full description of the molecule was published in 2022 by Coskun and colleagues, researchers at Eli Lilly and Company, in the journal Cell Metabolism (doi:10.1016/j.cmet.2022.07.013, PubMed 35985340). In cell assays on recombinant receptors, balanced activity was reported for LY3437943 at GCGR and GLP-1R, and stronger activity at GIPR.

To place these terms: GIPR, GLP-1R and GCGR belong to class B of the G protein-coupled receptors. In the lab, their activation is most often measured by cAMP production in cells that express the receptor under study. The concentration giving half of the maximum response (the EC50) is then compared with that of the receptor's natural ligand. "Balanced" activity at two receptors means those relative potencies were of the same order of magnitude.

That profile, described on cell models, is what makes the molecule a reference substance for comparative work on multi-receptor agonists. Our own data cover only the chemistry of the vial (identity, purity, amount). OXpeptides has measured no biological activity and claims none.

07

The three Janoshik reports, size by size

Janoshik Analytical is an independent testing laboratory. Each report carries a task number and a key that open it directly on the laboratory's own website, so the check never goes through us. Click the number in the table to open Janoshik's verification page.

All three lots exceed the 99% specification. On quantity, Janoshik measured 10.59 mg in the 10 mg vial, 21.88 mg in the 20 mg vial and 32.09 mg in the 30 mg vial. In all three sizes the vial therefore holds a little more than the label states.

The reports are also gathered in the certificate of analysis library, with those of the other peptides in the catalogue. How to read and check one field by field: Janoshik test report. The lot number is in the report; the vial itself carries the name of the substance and its net amount in milligrams.

08

Reading an analysis report: purity, identity, amount

Purity comes from high-performance liquid chromatography (HPLC). The column separates the components of the sample, each one leaves as a peak, and purity is the area share of the main peak. Reading 99.763% for lot PC260705RT20 means that, in this sample, 99.763% of the detected peptide area belongs to the expected molecule. The rest is close synthesis by-products, truncated chains for example.

Identity is checked by mass spectrometry, which compares the measured mass with the expected mass of about 4,731 g/mol. The two measurements complement each other. High purity without an identity check could describe a very pure peptide that is not the right one.

Amount answers the question many product pages leave out: how much peptide the vial really contains. The amount printed on the label is a promise. The measured amount is the proof.

What these reports do not cover: endotoxins, heavy metals and sterility were not tested on these lots, and we do not claim them anywhere. A report proves what is written on it, for the lot it names, and nothing more.

09

Before you buy retatrutide, seven checks

Whether you order here or elsewhere, these points take a few minutes to check, and a serious seller documents them without being asked.

• One report per size. A report on the 10 mg vial says nothing about a 30 mg vial.
• A check at the laboratory, with number and key. A PDF with no way to verify it is just an image.
• The measured amount, as well as the purity.
• A date and a lot number in the report.
• Shipping from inside the European Union, tracked, to avoid customs.
• A written return policy, with a stated time limit.
• A seller who refuses to advise on use. One who hands out amounts to use for a research product is no longer selling a reagent.

For this vial, all seven are on the page: three reports, three verifiable numbers, three measured amounts, lots and dates, shipping from the European Union in 4 to 6 working days, returns accepted for 30 days.

10

Storage and handling

• Temperature: −20 °C, sealed (short term ≤ 4 weeks: 2 to 8 °C).
• Conditions: Keep sealed, protected from light and moisture.
• Shelf life: 18 months (lyophilized, sealed).

A lyophilized peptide is far more stable as a closed powder than in solution. The vials therefore travel as powder, sealed and packed cold. On arrival, a vial that will not be opened in the coming weeks goes in the freezer. Avoid moving an open vial back and forth between cold and warm several times, and keep it away from light.

In the lab, the rules for any hygroscopic powder apply. Let the vial come back to room temperature before opening it, so that condensation does not settle on the powder. Work with clean equipment. Date every container. The choice of solvent, concentrations and experimental design belongs to the researcher, and we give no instructions on it.

11

Delivery to Ireland and across the EU

Every order is prepared in 1 to 2 working days, then leaves our stock inside the European Union with a tracking number. Allow 4 to 6 working days between order and delivery, to Ireland as to the other served countries. The tracking link arrives by e-mail as soon as the parcel is handed to the carrier.

• Home delivery €9.90, free from €120 of products (after the multi-vial discount).
• Prices and payment in euros, so an Irish card pays the amount shown with no conversion.
• No customs duty or import VAT on arrival in Ireland: the parcel moves inside the EU single market.
• Plain, sealed standard carton, with no product name on the outside.
• Returns accepted for 30 days on sealed vials, with a full refund; the conditions are in the refund policy.

Countries served, delivery times and rates are listed on the shipping page. The exact total, shipping included, shows before payment as soon as the address is entered, and that total is what is charged.

12

Status of the molecule and research use only

Retatrutide is an investigational molecule developed by Eli Lilly and Company and is not authorised for any human use, in Ireland, by the EMA or elsewhere. OXpeptides has no link with Eli Lilly. We supply this compound as a documented research reagent, to researchers and laboratories. Research use only, not for human or veterinary use.

That position has practical consequences, which we apply without exception. No amounts and no instructions for use, even on request. No certificate announced that does not exist. No customer review that does not come from a verified order. It is less comfortable for some buyers, and it is what makes the figures on this page reliable.

13

Short glossary

• Lyophilisate: powder obtained by freeze-drying under vacuum; the water is removed, the peptide stays dry and stable.
• Lot: one production run of common origin, covered by the same report.
• Nominal amount: the one on the label (10, 20 or 30 mg); the measured amount is in the report.
• Agonist: a molecule that activates a receptor; a triple agonist activates three.
• EC50: the concentration that produces half of the maximum response in an assay.
• HPLC: high-performance liquid chromatography, the method used to measure purity.
• Task number and key: the two references that make a Janoshik report publicly verifiable.
• RUO (Research Use Only): reserved for research.

14

Other documented research peptides

The research peptide catalogue applies the same rule to every product: a published, verifiable report per lot as soon as it exists. Among the most requested:

• GHK-Cu, the copper tripeptide Gly-His-Lys, one of the most searched peptides in the catalogue;
• BPC-157, a pentadecapeptide of 15 amino acids;
• TB-500, the synthetic fragment of thymosin beta-4;
• Selank and Semax, two synthetic heptapeptides.