Retatrutide: clinical evidence record
Also known as: LY3437943
Oliver Mackman · Editorial director · Best Business Loans Ltd (16833937)
Last updated 2026-05-22
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AI-friendly summary · Retatrutide
Eli Lilly investigational compound (LY3437943). Phase 2 trial data reports double-digit body-weight reduction at 48 weeks. Phase 3 TRIUMPH programme is in progress. Not licensed in any jurisdiction.
Mechanism of action
How Retatrutide works
Synthetic peptide acting as a triple agonist at three distinct receptors simultaneously: GLP-1, GIP, and glucagon. Combines appetite suppression, insulin sensitivity, and glucagon-mediated energy expenditure in a single molecule.
Top peer-reviewed citations
Selection of the most-cited peer-reviewed literature on Retatrutide. Where a verified PMID or DOI is shown, the citation links to the original record. Other citations list the title, authors, journal and year so the reader can locate the paper through the journal index or the PubMed search linked below. PeptideClear publishes editorial commentary, not clinical guidance.
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Triple-hormone-receptor agonist retatrutide for obesity: a phase 2 trial
Jastreboff AM, Kaplan LM, Frias JP, et al.. New England Journal of Medicine, 2023.
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Retatrutide for type 2 diabetes phase 2 trial
Rosenstock J, Frias J, Jastreboff AM, et al.. The Lancet, 2023.
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Retatrutide pharmacology of triple GLP-1 GIP glucagon receptor agonism
Coskun T, Urva S, Roell WC, et al.. Cell Metabolism, 2022.
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Hepatic effects of retatrutide in metabolic dysfunction-associated steatohepatitis
Sanyal AJ, Bedossa P, Fraessdorf M, et al.. New England Journal of Medicine, 2024.
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Effects of retatrutide on body composition in people with type 2 diabetes: a substudy of a phase 2, double-blind, parallel-group, placebo-controlled, randomised trial
Coskun T, Wu Q, Schloot NC, et al.. The lancet. Diabetes & endocrinology, 2025.
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Decreases in circulating ANGPTL3/8 concentrations following retatrutide treatment parallel reductions in serum lipids
Wen Y, Lemen D, Lin Y, et al.. Diabetes, obesity & metabolism, 2025.
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Retatrutide for the treatment of obesity, obstructive sleep apnea and knee osteoarthritis: Rationale and design of the TRIUMPH registrational clinical trials
Giblin K, Kaplan LM, Somers VK, et al.. Diabetes, obesity & metabolism, 2026.
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Rationale, Design, and Baseline Characteristics of the TRANSCEND-CKD trial of Retatrutide in Patients with Chronic Kidney Disease
Heerspink HJL, van Raalte DH, Bjornstad P, et al.. Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 2025.
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Appetite, eating attitudes, and eating behaviours during treatment with retatrutide in adults with type 2 diabetes: Results of a phase 2 study
Kanu C, Boye KS, Poon JL, et al.. Diabetes, obesity & metabolism, 2025.
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Efficacy and safety of retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial
Bajaj HS, Welch M, Shah P, et al.. Lancet (London, England), 2026.
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Synergistic Intervention for Obesity: Integrating Central Appetite Regulation and Peripheral Energy Expenditure
Xie J, Yang Y, Chen W, et al.. Current obesity reports, 2026.
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A Hydrophobic Tag-Assisted Liquid-Phase Strategy for the Synthesis of Retatrutide
Mao CY, Pang ZJ, Qiao GY, et al.. Organic letters, 2026.
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Retatrutide: Triple acting jab for type 2 diabetes lowers blood sugar and boosts weight loss, trial reports
Lang K. BMJ (Clinical research ed.), 2026.
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Do GLP-1 Receptor Agonists Sabotage Fat Grafts? : A Scoping Review of GLP-1 Receptor Agonist Effects on Adipocyte Biology and Implications for Autologous Fat Transfer
Chalhoub X, Yang Ng Z. Aesthetic surgery journal, 2026.
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Beyond weight loss: multisystem benefits of obesity medications
Savas M, Kuckuck S, Boon MR, et al.. The lancet. Diabetes & endocrinology, 2026.
Full PubMed search: https://pubmed.ncbi.nlm.nih.gov/?term=retatrutide+LY3437943.
UK regulatory status
Plain-English summary of where Retatrutide sits under the four UK and international frameworks that govern peptide supply. Editorial commentary, not legal advice.
- Misuse of Drugs Act 1971: Not controlled under the Misuse of Drugs Act 1971.
- Psychoactive Substances Act 2016: Not scheduled under the Psychoactive Substances Act 2016.
- MHRA medicines classification: No UK marketing authorisation as a medicine.
- WADA Prohibited List: Not currently listed on the WADA Prohibited List.
Full regulatory record: Retatrutide UK regulatory status.
Risks and unknowns
What the literature does not yet show about Retatrutide
Known concerns
- Most published efficacy claims for Retatrutide require careful interpretation. Read the cited papers in full before drawing conclusions.
- Purity of UK research-peptide supply varies between retailers. Certificates of analysis and HPLC documentation differ.
- Cold-chain handling between manufacture and delivery is not standardised across the research-peptide market.
- Independent replication of single-group findings is the key check on any preclinical claim.
Open questions in the literature
- Where human pharmacokinetics have not been formally characterised, dose translation from animal models is not reliable.
- Long-term safety profile beyond the duration of published studies remains an open question.
- Interactions with other prescribed or unlicensed substances are typically not studied.
Regulatory note
No UK marketing authorisation as a medicine. Not currently listed on the WADA Prohibited List. The moment a UK seller or commentator makes a therapeutic claim, MHRA can treat the product as an unlicensed medicinal product.
Important: PeptideClear publishes encyclopedia commentary only and does not recommend human use. Speak to a UK-registered prescriber before any medical decision.
Related reading on PeptideClear
Encyclopedia entry
Retatrutide: what it is, animal evidence, regulatory framing
Editorial commentary on Retatrutide, including the literature base and UK availability framing.
UK regulatory record
Retatrutide: UK regulatory status
MoDA, PSA, MHRA, WADA and ASA positions for Retatrutide in plain English.
Frequently asked questions
What is the evidence level for Retatrutide?
What is the UK regulatory status of Retatrutide?
Has Retatrutide been tested in human clinical trials?
Where can I read the source literature for Retatrutide?
Last verified 2026-05-22. Editorial commentary, not legal or clinical advice. Citations without a linked identifier can be located through the PubMed search and the journal index.