Retatrutide Research Peptide – 99%+ Pure

Every batch ships straight from the lab that synthesises it — sealed, tamper-evident, and HPLC-verified to >99% purity with a published batch Certificate of Analysis. View the batch Certificate of Analysis → Buying direct means you pay the lab-direct rate on every vial, with nothing stacked on top.

Order a sealed 10-vial research pack , or add a single-vial laboratory sample alongside your pack to evaluate a compound at smaller scale first. Same lab, same batch, same verified purity — scaled to whatever your research needs.

GLP1-RC-RT Batch Verification

Each released GLP1-RC-RT batch is independently analysed for chemical purity and identity, with the applicable laboratory report linked to the product batch.

New-U GLP1-RC-RT batch evidence

Catalogue identifier: GLP1-RC-RT

Batch number, vial count and declared mass per vial

RP-HPLC purity result for the released batch

Mass-spectrometry identity result for the released batch

Independent testing laboratory, report number and test date

Batch-linked Certificate of Analysis at /coa/retatrutide

Batch analysis reports identity and purity for the sample tested. It does not establish sterility, endotoxin or heavy-metal status, pharmaceutical equivalence, or any clinical property.

Published scientific literature

External experimental and clinical studies

Receptor pharmacology and pharmacokinetics

Protocol-defined trial endpoints and timepoints

Adverse events recorded by investigators

Registered trial records and peer-reviewed citations (DOI / PMID / NCT)

Published clinical findings summarised on this page relate to the investigational materials and protocols used in those external studies. They do not establish the safety, efficacy, intended use or clinical equivalence of New-U GLP1-RC-RT research material.

Published Research Areas

Published studies examine receptor activity, pharmacokinetics and protocol-defined metabolic, hepatic and glycaemic endpoints. The summaries below report what investigators measured in those external studies and are not use instructions for the research material supplied here.

Receptor Pharmacology

GLP-1R / GIPR / GCGR agonist activity, characterised in published in-vitro receptor studies.

Metabolic Endpoints

Protocol-defined change from baseline in body mass, measured in randomised clinical research.

Hepatic Endpoints

Liver-fat fraction by MRI-PDFF, measured in a randomised Phase 2a substudy.

Glycaemic Endpoints

HbA1c and glucose-related endpoints, reported in protocol-defined clinical research.

Pharmacokinetics

Systemic exposure and apparent elimination half-life, from published pharmacokinetic characterisation.

Overview

In short: GLP1-RC-RT is a triple GLP-1R / GIPR / GCGR agonist research compound, commonly referred to as “Reta” in research communities.

Key research facts

Receptor pharmacology: agonist activity characterised at GLP-1R, GIPR and GCGR in published in-vitro studies

GIPR potency reported as 8.9-fold that of native GIP in receptor-pharmacology studies

Albumin-binding C20 fatty-diacid modification investigated as a contributor to prolonged systemic exposure

Phase 2 obesity RCT (NEJM 2023, PMID 37385275): investigators reported −24.2% mean change from baseline in body weight at week 48 (12 mg arm)

Phase 3 TRIUMPH-1 (NCT05929066; sponsor-reported topline, ADA 2026; not yet peer-reviewed): investigators reported −28.3% mean change from baseline in body weight at week 80 (12 mg arm)

These points summarise lab themes, not human outcomes.

Published work characterises the receptor pharmacology, structural modifications and pharmacokinetic profile of this compound class, alongside protocol-defined endpoints investigated across preclinical and registered clinical research.

New-U batch verification and external literature are separate evidence sets: batch testing establishes analytical identity and purity for the tested material; published studies describe their own investigational materials and protocols.

Read the full scientific overview

Molecular Architecture

Retatrutide (LY3437943) is an engineered 39-amino-acid peptide with a molecular weight of 4,894.6 Da, characterised in receptor-pharmacology studies as an agonist at three receptors: GLP-1, GIP and glucagon. The triple-receptor profile is referred to in the literature as a "GGG" tri-agonist.

Receptor Pharmacology

Reported EC50 values are 0.775 nM at GLP-1R, 0.0643 nM at GIPR and 5.79 nM at GCGR, with GIPR potency reported as 8.9-fold that of native GIP. Relative to the dual GLP-1/GIP class, the additional arm under investigation is glucagon-receptor agonism; published work examines hepatic energy-expenditure endpoints associated with that arm alongside the incretin endpoints measured for the class as a whole. Full pathway table: Mechanism of Action below.

Structural Modifications

The GIP-derived backbone carries Aib2 and Aib20 substitutions investigated for DPP-IV resistance and α-methylleucine at position 13 investigated for protease stability. A Lys17-linked C20 fatty diacid via an AEEA-γGlu spacer is investigated as an albumin-binding contributor to prolonged systemic exposure.

Published Pharmacokinetics

Apparent elimination half-life is reported at approximately 6 days under the investigated protocols, with hepatic proteolytic metabolism and no CYP-mediated interaction reported. Full pharmacokinetic profile: Pharmacokinetics below.

Preclinical & Clinical Research

Published findings summarised on this page relate to external experimental and clinical studies and their respective investigational materials and protocols. They do not establish the safety, efficacy or clinical equivalence of New-U GLP1-RC-RT material. Trial-by-trial results: Research Observed Effects and Evidence Tier below.

Primary References

Peer-reviewed publications and the registered clinical-trial record for Retatrutide are listed in full, with DOI/PMID/NCT identifiers, in Source References below.

Receptor Pharmacology

Published experimental work characterises agonist activity across GLP-1R, GIPR and GCGR, with structural modifications investigated for proteolytic stability and prolonged systemic exposure.

Pathway Effect Why it matters GLP-1R Agonist activity characterised in receptor pharmacology studies Reported EC50 0.775 nM; the receptor shared with the single- and dual-agonist reference compounds GIPR Agonist activity characterised experimentally Reported EC50 0.0643 nM; potency reported as 8.9-fold that of native GIP GCGR Agonist activity characterised experimentally Reported EC50 5.79 nM; the arm that distinguishes the triple agonist from dual GLP-1/GIP compounds in the literature Albumin-binding modification C20 fatty diacid via an AEEA-γGlu spacer Investigated as a contributor to prolonged systemic exposure (~6-day apparent half-life) Proteolytic stability Aib2, Aib20 and α-methylleucine-13 substitutions Structural modifications investigated for altered peptide stability against DPP-IV and protease cleavage

Deeper dive for scientific readers

Jastreboff et al. (N Engl J Med, 2023; PMID 37385275, DOI 10.1056/NEJMoa2301972) published the randomised Phase 2 obesity data: in the 12 mg arm investigators reported a mean change from baseline in body weight of −24.2% at week 48, with more than 90% of participants in that arm reaching a ≥10% reduction. Sanyal et al. (Nat Med, 2024; DOI 10.1038/s41591-024-03018-2) reported relative reductions in hepatic fat fraction of up to 82.4% in a Phase 2a MASLD population. The Phase 3 TRIUMPH-1 trial (NCT05929066) reported a mean change from baseline in body weight of −28.3% at week 80 in the 12 mg arm, with 45.3% of that arm reaching a ≥30% reduction — sponsor-reported topline, ADA 2026; not yet peer-reviewed. Published pharmacokinetic work reports hepatic proteolytic metabolism without CYP involvement and steady-state exposure after 3–4 weeks of the protocol-defined weekly administration. Every figure here is an observation recorded in the cited external study of the investigational compound.

Common Questions People Are Asking

What is GLP1-RC-RT?

GLP1-RC-RT is New-U's catalogue designation for this analytically verified research compound, commonly referred to as “Reta” within research communities. It is supplied as laboratory research material: not a medicine, a treatment, a generic pharmaceutical or a therapeutic product, not equivalent to any clinical or commercial product, and not offered for human or veterinary use.

Which receptor systems have been investigated?

Published in-vitro pharmacology characterises agonist activity at three receptors: GLP-1R (reported EC50 0.775 nM), GIPR (reported EC50 0.0643 nM, with potency reported as 8.9-fold that of native GIP) and GCGR (reported EC50 5.79 nM). Structural work additionally investigates the C20 fatty-diacid albumin-binding modification as a contributor to prolonged systemic exposure, and Aib/α-methylleucine substitutions for altered proteolytic stability.

What analytical testing accompanies GLP1-RC-RT?

Each released GLP1-RC-RT batch is tested by an independent analytical laboratory (Janoshik Analytical or Freedom Diagnostics) for purity by RP-HPLC area normalisation and for identity by mass spectrometry, and the result is published as a batch-linked Certificate of Analysis recording the laboratory, report number, measured purity and test date. Batch analysis reports identity and purity for the sample tested. It does not establish sterility, endotoxin or heavy-metal status, pharmaceutical equivalence, or any clinical property.

Where can I view the current batch COA for GLP1-RC-RT?

The current batch certificate — laboratory, report number, measured purity and test date — is published at /coa/retatrutide, together with the testing history for the compound. It is readable before ordering rather than on request afterwards.

What does >99% HPLC purity mean?

It is a purity figure obtained by reversed-phase high-performance liquid chromatography using area normalisation: the target peak accounts for more than 99% of the total integrated peak area in the chromatogram for the tested sample. It is a statement about chemical purity of that sample only. It does not describe sterility, endotoxin content, heavy-metal content, pharmaceutical equivalence or any clinical property.

What clinical trials are referenced on this page?

Three external studies of the investigational compound: the randomised Phase 2 obesity trial (Jastreboff et al., N Engl J Med 2023; PMID 37385275, DOI 10.1056/NEJMoa2301972), the Phase 2a MASLD trial (Sanyal et al., Nat Med 2024; DOI 10.1038/s41591-024-03018-2) and the Phase 3 TRIUMPH-1 trial (ClinicalTrials.gov NCT05929066). Each reported result on this page is attributed to its study, arm and timepoint. TRIUMPH-1 figures are sponsor-reported topline presented at ADA 2026 and have not yet been peer-reviewed; the Phase 2 and Phase 2a figures come from peer-reviewed journal publications.

How is published clinical research distinguished from New-U batch testing?

They are separate bodies of evidence and this page keeps them apart. Published clinical research is external work on Retatrutide as an investigational compound, using those studies' own materials and protocols; it establishes nothing about the material supplied here. New-U batch testing is analytical work on the GLP1-RC-RT lot itself — RP-HPLC purity and mass-spectrometry identity — and it establishes nothing clinical. A certificate of analysis combined with an external clinical paper does not amount to clinical validation of GLP1-RC-RT.

What form is GLP1-RC-RT supplied in?

GLP1-RC-RT is supplied as a lyophilised powder in sealed vials, in single-vial laboratory samples and sealed 10-vial research packs across the listed strengths, with a batch-linked Certificate of Analysis.

How should laboratory research material be stored?

Store the lyophilised powder in a freezer at −20 °C. If a laboratory protocol requires the material in solution, hold the resulting solution refrigerated at 1–6 °C, protected from light, and avoid repeated freeze–thaw cycles, which can degrade the fatty-acid modification. Storage conditions are laboratory handling information only.

How does this receptor profile differ from the dual and single agonists?

The three classes are distinguished by receptor coverage: the semaglutide literature describes GLP-1R agonism, the tirzepatide literature describes GIPR/GLP-1R agonism, and this compound is investigated for GLP-1R/GIPR/GCGR agonism. Their clinical programmes were conducted separately, so published results from one programme are not head-to-head comparisons with another.

Is GLP1-RC-RT an approved medicine?

No. The associated compound is investigational and is being evaluated in registered clinical studies; it is not approved in any jurisdiction. The material supplied here is laboratory research material and is not offered as a medicine, therapeutic product, or material for human or veterinary use.

Is it legal to buy Retatrutide?

In the United States, Retatrutide is sold strictly for laboratory and research purposes only. It is not approved by the FDA for human consumption and is not sold for that purpose. Regulatory status varies by jurisdiction - buyers are responsible for compliance in their own region.

Research use only - all claims made on this site are for testing and research use only.

Pharmacokinetics

Half-life Apparent elimination half-life reported at approximately 6 days under the investigated protocols; steady-state exposure reported after 3–4 weeks Absorption route Study protocols used subcutaneous administration; reported Tmax 12–72 h with dose-proportional (linear) exposure Bioavailability High subcutaneous exposure with dose-proportional plasma levels reported Metabolism / clearance Hepatic proteolytic metabolism plus β-oxidation of the C20 fatty-diacid chain reported; no CYP-mediated interactions reported Stability Laboratory handling — lyophilised: −20 °C. Reconstituted: 1–6 °C, protect from light; avoid repeated freeze–thaw Notes The C20 fatty-diacid/albumin interaction is the protraction mechanism described in the published pharmacokinetic literature. These are pharmacokinetic observations from external studies of the investigational compound, not a handling or administration instruction for research material.

Research-Observed Effects

Phase 3 TRIUMPH-1 (NCT05929066), obesity/overweight population, 12 mg arm: investigators reported a mean change from baseline in body weight of −28.3% at week 80; 45.3% of that arm reached ≥30% reduction (sponsor-reported topline, ADA 2026; not yet peer-reviewed)

Phase 2 obesity RCT (Jastreboff et al., NEJM 2023; PMID 37385275), 12 mg arm: investigators reported a mean change from baseline in body weight of −24.2% at week 48, with >90% of that arm reaching ≥10% reduction

Phase 2a MASLD trial (Sanyal et al., Nat Med 2024): investigators reported relative hepatic fat-fraction reductions of up to 82.4% at the protocol-defined timepoint, with steatosis resolution reported in >90% of the 12 mg arm

Type 2 diabetes studies: investigators reported HbA1c reductions of 1.3–2.0% as a protocol-defined endpoint in the investigated arms

Experimental pharmacology: glucagon-receptor agonism is investigated in the literature as a contributor to hepatic energy-expenditure endpoints measured alongside the incretin endpoints

Published Research Context

Registered clinical research of the investigational compound used protocol-defined intervention arms. The Phase 2 programme included 1 mg, 4 mg, 8 mg and 12 mg arms; the Phase 3 TRIUMPH-1 trial randomised 4 mg, 9 mg and 12 mg arms against placebo. Study protocols used once-weekly subcutaneous administration with a protocol-defined step-up period of roughly 20–24 weeks before the maintenance arm level was reached.

These figures are characteristics of external clinical trials. They are recorded here as scientific study context and are not a protocol, schedule, starting point or instruction for any use of laboratory research material.

Adverse Events Reported in Published Clinical Research

The events below were recorded by investigators in published clinical trials of the investigational compound. They describe what was observed in those study populations under those protocols; they are not a prediction of, or guidance about, anything a reader may experience.

Common

Nausea — reported as the most frequent event, described as escalation-related and typically transient

Diarrhoea

Vomiting

Constipation

Decreased appetite recorded as a reported adverse event

Rare

Discontinuation due to adverse events, reported by arm in TRIUMPH-1: 4.1% (4 mg), 6.9% (9 mg), 11.3% (12 mg) vs 4.9% placebo

Transient increase in resting heart rate

Transient glucose elevation attributed to the glucagon-receptor arm, monitored under the study protocols

Dose-dependent

Investigators reported gastrointestinal events scaling with arm level and during the protocol-defined step-up period, attenuating at steady state

Higher arm levels were reported with both larger endpoint changes and a higher adverse-event discontinuation rate

Evidence Tier

Overall: Tier 1: Human clinical

The evidence tier describes the published literature on Retatrutide, the scientific subject. Retatrutide remains investigational and is not approved in any jurisdiction. Published clinical findings summarised on this page relate to the investigational materials and protocols used in those external studies. They do not establish the safety, efficacy, intended use or clinical equivalence of New-U GLP1-RC-RT research material.

Tier 1 · Human clinical

TRIUMPH-1 pivotal Phase 3 obesity RCT — −28.3% mean change from baseline in body weight at week 80 (NCT05929066; sponsor-reported topline, ADA 2026; not yet peer-reviewed)

Triple-agonist Phase 2 obesity RCT — −24.2% mean change from baseline at week 48 (NEJM 2023; PMID 37385275)

Phase 2a MASLD trial — up to 82.4% relative hepatic fat-fraction reduction (Nat Med 2024)

Certificates, databases & peer-reviewed sources

Last reviewed: 14 August 2026 · New-U Research Compounds

Jastreboff AM et al. Triple–Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial. N Engl J Med. · 2023 · PMID: 37385275 · DOI: 10.1056/NEJMoa2301972

Sanyal AJ et al. Triple hormone receptor agonist retatrutide for MASLD: a randomized phase 2a trial. Nat Med. · 2024 · DOI: 10.1038/s41591-024-03018-2

TRIUMPH-1: A Study of Retatrutide (LY3437943) in Participants Who Have Obesity or Overweight - Phase 3 (Pivotal). ClinicalTrials.gov trial registration record. · 2023

Eli Lilly and Company. Lilly’s triple agonist, retatrutide, delivered powerful weight loss in pivotal Phase 3 obesity trial. Sponsor announcement (topline; not peer-reviewed), presented at ADA 86th Scientific Sessions. · 2026

Katsi V, Koutsopoulos G, Fragoulis C, Dimitriadis K, Tsioufis K. Retatrutide - A Game Changer in Obesity Pharmacotherapy. Biomolecules (review). · 2025 · PMID: 40563436 · DOI: 10.3390/biom15060796

PubMed: peer-reviewed literature on Retatrutide

ClinicalTrials.gov: registered studies on Retatrutide

Retatrutide: Wikipedia (search)

WebMD: consumer health reference

BBC News: Health

CNN Health: “Peptides: what to know about the wellness trend”

Sky News: “Can peptides make America healthy again?”

Sky News: “Inside the exploding US peptides craze” (video)

Sky News Australia: “Black market peptide trade explodes as influencers fuel uptick in use”

Sky News Australia: “Backyard peptide boom sparks alarm” (video)

Sky News Australia: “Oprah reveals struggle with shame of weight-loss drugs”

Key Characteristics

Engineered 39-amino-acid peptide (LY3437943)

Agonist activity characterised at GLP-1R, GIPR and GCGR in receptor-pharmacology studies

GIPR potency reported as 8.9-fold that of native GIP

C20 fatty-diacid albumin-binding modification investigated for prolonged systemic exposure

Apparent elimination half-life reported at approximately 6 days in published pharmacokinetic research

GLP1-RC-RT laboratory research material — analytically verified, >99% HPLC purity

Supplied as lyophilised powder for laboratory research; not an approved medicine

Specifications

New-U catalogue identifier GLP1-RC-RT Scientific subject Retatrutide (LY3437943) Molecular Formula Complex lipopeptide (C20 diacid conjugate) Molecular Weight 4894.6 Da Receptors characterised GLP-1R (EC50 0.775 nM), GIPR (EC50 0.064 nM), GCGR (EC50 5.79 nM) Purity (analytical) >99% by RP-HPLC area normalisation Identity (analytical) Confirmed by mass spectrometry on the released batch Form Lyophilised powder Published half-life Approximately 6 days (external pharmacokinetic research) Storage Lyophilised: −20 °C freezer. Reconstituted: 1-6 °C, away from light. Intended use Laboratory research material. Not for human or veterinary use.

Retatrutide Research — GLP1-RC-RT Laboratory Research Material

Retatrutide (LY3437943) is investigated in the literature as the triple-receptor entrant in the incretin class. First-generation compounds such as semaglutide are characterised as GLP-1R agonists; dual compounds such as tirzepatide are characterised as GIPR/GLP-1R agonists; retatrutide adds glucagon-receptor agonism, which is why it is described as a "GGG" tri-agonist.

Published clinical research reports protocol-defined endpoints: a mean change from baseline in body weight of −24.2% at week 48 in the Phase 2 12 mg arm (NEJM 2023), −28.3% at week 80 in the Phase 3 TRIUMPH-1 12 mg arm (sponsor-reported topline, ADA 2026; not yet peer-reviewed), and relative hepatic fat-fraction reductions of up to 82.4% in a Phase 2a MASLD population (Nat Med 2024). Each of those figures belongs to the study that produced it, in the population and at the timepoint that study defined.

New-U Research Compounds supplies GLP1-RC-RT as lyophilised, analytically verified laboratory research material at >99% HPLC purity, with identity and purity confirmed by independent laboratories including Janoshik Analytical and Freedom Diagnostics. Batch analysis reports identity and purity for the sample tested. It does not establish sterility, endotoxin or heavy-metal status, pharmaceutical equivalence, or any clinical property. Published clinical findings summarised on this page relate to the investigational materials and protocols used in those external studies. They do not establish the safety, efficacy, intended use or clinical equivalence of New-U GLP1-RC-RT research material. GLP1-RC-RT is not an approved medicine and is not offered for human or veterinary use.

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Customer Reviews

Retatrutide COA matched

The COA trail was the best part of the order. The Retatrutide vial from New-U Research Compounds had clear batch info and it matched what was listed online. Makes checking much easier.

- Maya S**** · 30 August 2026

Simple and professional

No over complicated process. I bought Retatrutide from New-U, checked the COA, placed the order and it arrived properly sealed. That is basically what I wanted.

- Hassan Q****** · 30 August 2026

Clear batch details

The Retatrutide from New-U Research Compounds had proper batch details on the label, which made it simple to log into our records. Small thing, but it saves time when checking multiple vials.

- Rafael M****** · 30 August 2026

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Research peptides at >99% HPLC-verified purity, third-party tested by Janoshik Analytical & Freedom Diagnostics, with Certificates of Analysis published per released batch. Supplied strictly for laboratory research use.

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