Retatrutide (LY3437943)

Known, not known, contested

Chemistry: retatrutide as PubChem CID 171390338 records it

Sequence

YAQGTFTSDYSILLDKKAQAAFIEYLLEGGPSSGAPPPS

Length

39 residues

Modifications

2-methylalanine (Aib) at positions 2 and 20, 2-methyl-L-leucine at position 13, Lys17 acylated with a C20 fatty diacid through a gamma-glutamyl and aminoethoxy ethoxy acetyl linker, C-terminal amide

Formula

C221H342N46O68

Monoisotopic mass

4728.4718 Da

Average mass

4731 Da

CAS

2381089-83-2

PubChem CID

171390338

InChIKey

MLOLQJNKXBNWFW-SAGGEDDASA-N

Synonyms

LY3437943, LY-3437943

Salt form

sodium

Chemistry: identifiers and salt form

• The Global Substance Registration System records retatrutide under UNII NOP2Y096GV with CAS 2381089-83-2, INN and USAN entries for the name retatrutide, and the development code LY3437943. 2Source sentenceNames: Retatrutide [INN], RETATRUTIDE [USAN], LY3437943; codes: CAS 2381089-83-2 (PRIMARY), UNII NOP2Y096GV; protein subunit sequence YAQGTFTSDYSILLDKKAQAAFIEYLLEGGPSSGAPPPS (39 residues); relationships: GLUCAGON-LIKE PEPTIDE 1 RECEPTOR, GASTRIC INHIBITORY POLYPEPTIDE RECEPTOR and GLUCAGON RECEPTOR, each TARGET->AGONIST2 GSRS substance record, UNII NOP2Y096GV
• PubChem substance records named retatrutide (for example SID 438519203) map to compound CID 171390338, InChIKey MLOLQJNKXBNWFW-SAGGEDDASA-N. 3Source sentencePUG REST property table, CID 171390338: MolecularFormula C221H342N46O68; MW 4731; MonoisotopicMass 4728.4717592; ExactMass 4730.4784689; InChIKey MLOLQJNKXBNWFW-SAGGEDDASA-N. Substance records named retatrutide (for example SID 438519203) map to CID 1713903383 PubChem CID 171390338
• GSRS holds a separate record for retatrutide sodium (UNII LQ42M82ZU6), a salt form; the masses on this page are for the peptide without a counterion. 18Source sentenceroot_names_name RETATRUTIDE: total 2; Retatrutide NOP2Y096GV (protein); Retatrutide sodium LQ42M82ZU6 (protein); relationship SALT/SOLVATE->PARENT18 GSRS name search for retatrutide, 14 October 2026

Sequence

• The one letter sequence shows the 39 positions; the full name adds what one letter codes cannot: 2-methylalanine at positions 2 and 20, 2-methyl-L-leucine at position 13, the acylated Lys17 side chain and the C-terminal serinamide. 2Source sentenceSystematic name: L-Tyrosyl-2-methylalanyl-L-glutaminylglycyl-L-threonyl-L-phenylalanyl-L-threonyl-L-seryl-L-α-aspartyl-L-tyrosyl-L-seryl-L-isoleucyl-2-methyl-L-leucyl-L-leucyl-L-α-aspartyl-L-lysyl-N6-[N-(19-carboxy-1-oxononadecyl)-L-γ-glutamyl-2-[2-(2-aminoethoxy)ethoxy]acetyl]-L-lysyl-L-alanyl-L-glutaminyl-2-methylalanyl-L-alanyl-L-phenylalanyl ... -L-prolyl-L-prolyl-L-prolyl-L-serinamide2 GSRS substance record, UNII NOP2Y096GV

Which molecule does a certificate for retatrutide describe?

• Read the formula and mass on the certificate of analysis: C221H342N46O68 at about 4731 Da (average) fits retatrutide as PubChem records it (CID 171390338). Semaglutide, PubChem CID 56843331, is C187H291N45O59 at about 4114 Da. 3,19Source sentenceCID 171390338: MolecularFormula C221H342N46O68, MW 4731; CID 56843331 (title Semaglutide): MolecularFormula C187H291N45O59, MW 41143 PubChem CID 17139033819 PubChem CID 56843331
• Mass values for retatrutide differ by how they are computed: PubChem lists a monoisotopic mass of 4728.4718 Da, an exact mass of 4730.4785 Da and an average mass of 4731 Da, and a 2026 letter gives 4730.477 Da as the expected value for authentic retatrutide. 3,14,15Source sentencePubChem: MonoisotopicMass 4728.4717592; ExactMass 4730.4784689; MW 4731. PMC13445994, Results: "closely matching the expected ... of authentic retatrutide (4730.477 Da)"3 PubChem CID 17139033814 Drug Alcohol Rev 202615 PMC full text of the 2026 letter (PMID 42559975)
• A TGA laboratory test published on 14 Sep 2026 found undeclared semaglutide and no retatrutide in one product sold as retatrutide, obtained in its original unmarked vial. 16Source sentence"During its investigation, the TGA obtained a sample of the product contained in its original unmarked vial. TGA laboratory testing of the product found that: the product contained undeclared semaglutide and no retatrutide." Published 14 September 202616 TGA safety advisory, 14 September 2026
• A 2026 letter reports that an accredited laboratory found retatrutide in all three products sold as retatrutide that it tested; identity was checked by molecular mass and peptide content was measured separately. 14,15Source sentencePMC13445994, Methods: "Samples were analysed by an independent National Association of Testing Authorities-accredited laboratory. Peptide identity was confirmed using ... analysis. Peptide content was quantified"; Results: "The three samples contained retatrutide"14 Drug Alcohol Rev 202615 PMC full text of the 2026 letter (PMID 42559975)
• A 2026 LC-HRMS method validated against WADA criteria detects intact retatrutide through its [M+3H]3+ precursor ion, with confirmation from fragment ions. 20Source sentenceAbstract, Methods: "developed and validated in human plasma and urine in accordance with World Anti-Doping Agency (WADA) criteria. Detection was based on the [M + 3H]3+ precursor ion by targeted selected-ion monitoring (t-SIM), with confirmatory analysis via parallel reaction monitoring (PRM) of structurally diagnostic fragment ions."20 Rapid Commun Mass Spectrom 2026

What is retatrutide?

Is retatrutide "GLP-3"?

Which receptors does retatrutide act at?

What clinical trials of retatrutide exist?

Is retatrutide FDA approved?

US

When will retatrutide be available? What the records show

Evidence map: retatrutide

Who produced this evidence

• Eli Lilly and Company is lead sponsor of 32 of the 33 ClinicalTrials.gov records for retatrutide; the other, a phase 2 study in China (NCT07467447, recruiting), lists Hudson Biotech as lead sponsor. 7,37Source sentencequery.intr retatrutide: totalCount 33; phases PHASE1 14, PHASE2 4, PHASE3 14, one expanded access record (status AVAILABLE, no phase); phase 3 overall status COMPLETED 5, ACTIVE_NOT_RECRUITING 8, RECRUITING 1; lead sponsor Eli Lilly and Company 32, Hudson Biotech 1; NCT07467447: lead sponsor Hudson Biotech, Phase 2, RECRUITING, location China7 ClinicalTrials.gov search, 14 October 202637 NCT07467447
• All authors of the 2022 discovery paper are Lilly employees and stockholders, the Lilly authors of the 2022 phase 1b paper declare employment and shareholdings, and the 2023 Lancet and NEJM phase 2 papers and the three phase 3 papers state Eli Lilly funding. 5,33,34,26,9,8,1Source sentence35985340 COI: "All authors are employees and stockholders of Eli Lilly and Company"; 36354040 COI: "SU, TC, MTL, YD, SG, AH, CTB, and ZM are employees and shareholders of Eli Lilly and Company"; 37385280 and 42250575: "FUNDING: Eli Lilly and Company"; 37366315: "Funded by Eli Lilly"; 42814954: "Funded by Eli Lilly"; 42810372: funding Eli Lilly and Company5 Cell Metab 202233 Lancet 202234 Lancet 202326 N Engl J Med 20239 Lancet 2026, NCT063546608 N Engl J Med 2026, TRIUMPH-11 Lancet 2026, TRIUMPH-2
• The cell, animal and analytical studies on this page come from academic groups in Halle (Germany), Wuhan and Huai'an (China), Kütahya (Türkiye), San Diego (United States), Rio de Janeiro (the LADETEC laboratory, Brazil) and Brisbane (Australia); five of these papers declare no competing interests. 22,23,36,25,24,20,14Source sentenceAffiliations: Martin-Luther-University Halle-Wittenberg (40464942); South-Central Minzu University, Wuhan (42630988); Xuzhou Medical University, Huai'an (39212900); Kütahya Health Sciences University (42385950); University of California San Diego (41056349); LADETEC, Universidade Federal do Rio de Janeiro (42745421); University of Queensland, Brisbane (42559975). COI "no conflicts" or "no competing interests": 42745421, 42559975, 42630988, 39212900, 4238595022 Naunyn Schmiedebergs Arch Pharmacol 202523 iScience 202636 Endocrine 202525 Behav Brain Res 202624 Am J Physiol Gastrointest Liver Physiol 202520 Rapid Commun Mass Spectrom 202614 Drug Alcohol Rev 2026

Studies

1. In vitro or ex vivoCell Metab 2022

   Activity at the glucagon, GIP and GLP-1 receptors in vitro, metabolic measures in mice, and safety, tolerability and pharmacokinetics in a phase 1 study

   Design

   Receptor assays in vitro, mouse studies and a phase 1 study

   Population or model

   receptor assays in vitro, mice, and a phase 1 study

   Molecule

   retatrutide (LY3437943) exact

   Funding

   Eli Lilly and Company

   All authors declare employment and stock at Eli Lilly and Company (COI statement).

   PubMed 35985340DOI

2. Human, randomisedLancet 2022

   Safety and tolerability (primary), pharmacokinetics and glycaemic measures

   Design

   Phase 1b, randomised, double-blind, placebo-controlled, multiple ascending cohorts, with a dulaglutide arm

   Population or model

   adults with HbA1c of 7.0 to 10.5 percent, four US centres

   Molecule

   retatrutide (LY3437943) exact

   n

   72

   Comparator

   placebo; dulaglutide

   Blinding

   double-blind

   Duration

   12 weeks

   Funding

   Eli Lilly and Company

   Registration

   ClinicalTrials.gov NCT04143802

   Lilly authors declare employment and shareholdings (COI statement).

   PubMed 36354040DOI

3. Human, randomisedLancet 2023

   Change in HbA1c from baseline to 24 weeks (primary) and adverse events

   Design

   Phase 2, randomised, double-blind, double-dummy, placebo- and active comparator-controlled, parallel-group

   Population or model

   adults with HbA1c of 7.0 to 10.5 percent, 42 US centres

   Molecule

   retatrutide (LY3437943) exact

   n

   281

   Comparator

   placebo; dulaglutide

   Blinding

   double-blind

   Duration

   36 weeks

   Funding

   Eli Lilly and Company

   Registration

   ClinicalTrials.gov NCT04867785

   Authors report grants, consulting or speaker fees from Eli Lilly and Company and other companies (COI statement).

   PubMed 37385280DOI

4. Human, randomisedN Engl J Med 2023

   The primary endpoint at 24 weeks as registered (NCT04881760), secondary endpoints at 48 weeks, adverse events and heart rate

   Design

   Phase 2, randomised, double-blind, placebo-controlled

   Population or model

   adults, registry NCT04881760

   Molecule

   retatrutide (LY3437943) exact

   n

   338

   Comparator

   placebo

   Blinding

   double-blind

   Duration

   48 weeks

   Funding

   Eli Lilly and Company

   Registration

   ClinicalTrials.gov NCT04881760

   PubMed 37366315DOI

5. Human, randomisedNat Med 2024

   Relative change in liver steatosis from baseline at 24 weeks (primary)

   Design

   Phase 2a substudy, randomised, double-blind, placebo-controlled

   Population or model

   participants with metabolic dysfunction-associated steatotic liver disease from the phase 2 trial NCT04881760

   Molecule

   retatrutide (LY3437943) exact

   n

   98

   Comparator

   placebo

   Blinding

   double-blind

   Duration

   48 weeks

   Registration

   ClinicalTrials.gov NCT04881760

   Authors report consulting or advisory ties to Eli Lilly and Company and other companies (COI statement).

   PubMed 38858523DOI

6. Human, randomisedLancet 2026

   Change in HbA1c from baseline to week 40 (primary) and adverse events

   Design

   Phase 3, randomised, double-blind, placebo-controlled

   Population or model

   adults with HbA1c of 7.0 to 9.5 percent on diet and exercise alone, 48 sites in the USA, Mexico and India

   Molecule

   retatrutide (LY3437943) exact

   n

   537

   Comparator

   placebo

   Blinding

   double-blind

   Duration

   40 weeks

   Funding

   Eli Lilly and Company

   Registration

   ClinicalTrials.gov NCT06354660

   Authors report research support, speaker fees or stock tied to Eli Lilly and Company and other companies (COI statement).

   PubMed 42250575DOI

7. Human, randomisedN Engl J Med 2026

   The primary endpoints as registered (NCT05929066)

   Design

   Phase 3, randomised, double-blind, placebo-controlled (TRIUMPH-1)

   Population or model

   adults, with knee osteoarthritis and obstructive sleep apnea subsets

   Molecule

   retatrutide (LY3437943) exact

   n

   2339

   Comparator

   placebo

   Blinding

   double-blind

   Duration

   80 weeks

   Funding

   Eli Lilly and Company

   Registration

   ClinicalTrials.gov NCT05929066

   n is the number randomised in the abstract; the registry lists 2,335 enrolled.

   PubMed 42814954DOI

8. Human, randomisedLancet 2026

   The primary endpoint at week 80 as registered (NCT05929079), glycaemic measures and adverse events

   Design

   Phase 3, randomised, double-blind, placebo-controlled, parallel-group (TRIUMPH-2)

   Population or model

   adults with HbA1c of 6.5 to 10.5 percent, 92 centres in eight countries

   Molecule

   retatrutide (LY3437943) exact

   n

   1152

   Comparator

   placebo

   Blinding

   double-blind

   Duration

   80 weeks

   Funding

   Eli Lilly and Company

   Registration

   ClinicalTrials.gov NCT05929079

   Authors report consulting, speaker or research ties to Eli Lilly and Company and other companies (COI statement).

   PubMed 42810372DOI

9. Analytical only (no biological model)Rapid Commun Mass Spectrom 2026

   LC-HRMS detection of intact retatrutide in plasma and urine, limits of detection and the plasma time course

   Design

   LC-HRMS method development and validation to WADA criteria, with plasma and urine time courses

   Population or model

   human plasma and urine samples from 4 individuals

   Molecule

   retatrutide (LY3437943) exact

   n

   4

   The authors declare no conflicts of interest.

   PubMed 42745421DOI

10. Analytical only (no biological model)Drug Alcohol Rev 2026

    Identity by molecular mass and peptide content per vial

    Design

    Laboratory analysis of products (letter)

    Population or model

    three products sold as retatrutide in Australia

    Molecule

    retatrutide (LY3437943) exact

    n

    3

    The authors declare no conflicts of interest.

    PubMed 42559975DOI

11. In vitro or ex vivoNaunyn Schmiedebergs Arch Pharmacol 2025

    Force of contraction and beating rate, with a glucagon receptor antagonist and a protein kinase A inhibitor

    Design

    Isolated organ pharmacology

    Population or model

    isolated left and right atrial preparations from adult CD1 mice

    Molecule

    retatrutide (LY3437943) exact

    Comparator

    isoprenaline; receptor antagonists and pathway inhibitors

    PubMed 40464942DOI

12. RodentiScience 2026

    Renal fibrosis and inflammation markers, PI3K-AKT and NF-kB pathway activity, and G2/M arrest in the aging model

    Design

    Cell and mouse comparison with semaglutide and tirzepatide

    Population or model

    HK-2 kidney cells; mouse unilateral ureteral obstruction (UUO) and aging models

    Molecule

    retatrutide (LY3437943) exact

    Comparator

    semaglutide; tirzepatide

    The authors declare no competing interests.

    PubMed 42630988DOI

13. RodentEndocrine 2024

    Blood glucose, serum biochemistry, renal inflammation and fibrosis markers, and intestinal butyrate

    Design

    Mouse comparison with liraglutide and tirzepatide

    Population or model

    db/db mice, 10 weeks

    Molecule

    retatrutide (LY3437943) exact

    Comparator

    liraglutide; tirzepatide

    Duration

    10 weeks

    The authors declare no competing interests.

    PubMed 39212900DOI

14. RodentBehav Brain Res 2026

    Learning and memory tasks, hippocampal cytokines, BDNF, CREB and AKT expression, Tau protein and brain histology

    Design

    Controlled rat study with four groups

    Population or model

    male Sprague-Dawley rats, streptozotocin-induced insulin-deficient model

    Molecule

    retatrutide (LY3437943) exact

    Comparator

    control, streptozotocin-only and retatrutide-only groups

    The authors declare no competing interests.

    PubMed 42385950DOI

15. RodentAm J Physiol Gastrointest Liver Physiol 2025

    ALT, hepatic triglycerides and cholesterol, hepatic inflammatory markers and liver gene expression

    Design

    Mouse model development plus a vehicle-controlled intervention

    Population or model

    C57BL/6N mice, 31-day diet-induced steatohepatitis model

    Molecule

    retatrutide (LY3437943) exact

    Comparator

    vehicle

    Duration

    2 weeks of a 31-day model

    PubMed 41056349DOI

Receptors and signalling studied

• A 2022 discovery paper describes LY3437943 as an agonist at the glucagon, GIP and GLP-1 receptors and measured its activity at each of the three receptors in vitro. 5Source sentenceAbstract: "LY3437943 is a novel triple agonist peptide at the glucagon receptor (GCGR), glucose-dependent insulinotropic polypeptide receptor (GIPR), and glucagon-like peptide-1 receptor (GLP-1R)." The abstract then reports in vitro activity at GCGR, GLP-1R and GIPR5 Cell Metab 2022
• A 2025 study in isolated mouse atrial preparations measured beating rate and force of contraction, and used a glucagon receptor antagonist and a protein kinase A inhibitor to test which receptor and pathway were involved. 22Source sentenceAbstract: preparations "from adult CD1 mice"; "antagonized by adomeglivant, a GCGR antagonist"; "attenuated by H89, an inhibitor of the cAMP-dependent protein kinase (PKA)"22 Naunyn Schmiedebergs Arch Pharmacol 2025
• A 2026 study measured renal fibrosis and inflammation markers and PI3K-AKT and NF-kB pathway activity in HK-2 kidney cells and in mouse UUO and aging models, alongside semaglutide and tirzepatide. 23Source sentenceAbstract: "... renal fibrosis using HK-2 cells and murine UUO and aging models"; the abstract reports PI3K-AKT and NF-κB pathway measures for each agent23 iScience 2026
• A 2025 study in db/db mice measured blood glucose, serum biochemistry, renal inflammation and fibrosis markers and intestinal butyrate, alongside liraglutide and tirzepatide. 36Source sentenceAbstract, Methods: "we measured and compared the renal inflammation and fibrosis indexes"; "the content of intestinal metabolite butyrate was compared"36 Endocrine 2025
• A 2026 study in a streptozotocin-induced, insulin-deficient rat model measured learning and memory tasks, hippocampal cytokines, BDNF, CREB and AKT expression, Tau protein and brain histology. 25Source sentenceAbstract: "hippocampal cytokine levels (IL-1β, TNF-α), BDNF, CREB, and AKT mRNA expression, Tau protein levels, and cortical and hippocampal histopathology were evaluated"25 Behav Brain Res 2026
• A 2025 study in a 31-day diet-induced mouse model of steatohepatitis measured ALT, hepatic triglycerides and cholesterol, hepatic inflammatory markers and liver gene expression. 24Source sentenceAbstract: "a new 31-day mouse model of diet-induced steatohepatitis"; measures "ALT levels, hepatic triglycerides and cholesterol, and hepatic inflammatory markers"; "hepatic gene expression profile per RNA sequencing"24 Am J Physiol Gastrointest Liver Physiol 2025

Status matrix

• FDA

  No authorisation found 2727 openFDA Drugs@FDA query for retatrutide, 14 October 2026

  No Drugs@FDA record for retatrutide

  Checked 14 October 2026

• WADA

  Not named 3838 WADA Prohibited List 2026

  Not named in the 2026 list

  List version: 2026In force from 1 January 2026Checked 14 October 2026

United States: FDA records, import alert and court filings

US

• No application or product containing retatrutide was found in openFDA Drugs@FDA on 14 Oct 2026. 27Source sentence"NOT_FOUND": "No matches found!" (products.active_ingredients.name, openfda.generic_name and openfda.substance_name RETATRUTIDE)27 openFDA Drugs@FDA query for retatrutide, 14 October 2026
• FDA warning letters name retatrutide products of Prime Vitality Inc (10 Dec 2024), Gram Peptides (31 Mar 2026) and five sellers on 24 Aug 2026: Royal Peptides, Peptide Partners, Tex Peptides, NuScience Peptides and Peak Performance Peptides. 28,29,30,39,40,41,42Source sentence695156: "Semaglutide" and "Retatrutide"; 721806: "Retatrutide (also referred to as GLP-1-R Peptide)"; 734884, 735063, 735067, 733652 and 735127, each dated August 24, 2026, list a retatrutide product28 FDA warning letter 695156 (Prime Vitality Inc), 10 December 202429 FDA warning letter 721806 (Gram Peptides), 31 March 202630 FDA warning letter 734884 (Royal Peptides LLC), 24 August 202639 FDA warning letter 735063 (Peptide Partners LLC), 24 August 202640 FDA warning letter 735067 (TXP Innovations LLC dba Tex Peptides), 24 August 202641 FDA warning letter 733652 (NuScience Peptides LLC), 24 August 202642 FDA warning letter 735127 (Peak Performance Peptides), 24 August 2026
• The 24 Aug 2026 letter to Royal Peptides states that its "Retatrutide" and other listed products "are unapproved new drugs under section 505(a) of the Federal Food, Drug, and Cosmetic Act". 30Source sentence"Based on our review, “Tirzepatide,” “Semaglutide,” “Retatrutide,” ... are unapproved new drugs under section 505(a) of the Federal Food, Drug, and Cosmetic Act (FD&C Act)"30 FDA warning letter 734884 (Royal Peptides LLC), 24 August 2026
• Product names quoted in the 24 Aug 2026 letters include "GLP-3 Reta (Retatrutide)", "Retatrutide (GLP-3 RT)", "GLP-3 RT (Retatrutide)" and "GLP-3R" (retatrutide). 39,40,41,42Source sentence735063: “GLP-3 Reta (Retatrutide)”; 735067: “Retatrutide (GLP-3 RT)”; 733652: “GLP-3 RT (Retatrutide) Research Peptide”; 735127: “GLP-3R” (retatrutide)39 FDA warning letter 735063 (Peptide Partners LLC), 24 August 202640 FDA warning letter 735067 (TXP Innovations LLC dba Tex Peptides), 24 August 202641 FDA warning letter 733652 (NuScience Peptides LLC), 24 August 202642 FDA warning letter 735127 (Peak Performance Peptides), 24 August 2026
• FDA Import Alert 66-80, on detention without physical examination of GLP-1 receptor agonist bulk drug substances (published date 21 Sep 2026), covers product codes where the importer description contains the word retatrutide. 43Source sentence"Import Alert # 66-80 Published Date: 09/21/2026 Type: DWPE Import Alert Name: Detention Without Physical Examination of Glucagon-Like Peptide-1 (GLP-1) Receptor Agonist Bulk Drug Substances"; product list: "and the importer description contains the word, Retatrutide"43 FDA Import Alert 66-80, published date 21 September 2026
• On 12 Aug 2026 Eli Lilly and Company announced six lawsuits against US sellers of retatrutide products, filed against Aesthetic Envy (N.D. Cal.), Astra Peptides (W.D. Tex.), Legendary Peptides (E.D. Tex.), Striker Pharmacy (S.D. Tex.), Texas Peptides (W.D. Tex.) and Lone Star Peptide Co. (S.D. Tex.). 4Source sentence"filing six new lawsuits against U.S. entities selling black-market products"; "Lilly's lawsuits include: Eli Lilly & Co. v. Aesthetic Envy Cosmetic Centers LLC ... (N.D. Cal.); ... Astra Peptides (W.D. Tex.); ... Legendary Peptides, LLC (E.D. Tex.); ... Striker Pharmacy, LLC (S.D. Tex.); ... Texas Peptides Inc. (W.D. Tex.); ... Lone Star Peptide Co. (S.D. Tex.)"4 Eli Lilly and Company news release, 12 August 2026
• A report by the consumer group Public Citizen dated 16 Jun 2026 counts 14 FDA warning letters sent since Dec 2024 to companies that sold retatrutide, and states that as of May 2026, 11 of the 14 recipients continued to advertise retatrutide or other peptide drugs FDA has not approved. 44Source sentence"Since December 2024, the FDA has issued 14 warning letters to companies that sold retatrutide ..."; Key Findings: "As of May 2026, 11 of the 14 sellers that received letters continued to advertise retatrutide or other peptide drugs that the FDA has not approved." Report dated June 16, 202644 Public Citizen report, 16 June 2026

Sport anti-doping list

International

• The WADA 2026 Prohibited List does not name retatrutide or LY3437943 (text search of the list on 14 Oct 2026). 38Source sentenceNo match for retatrutide, LY3437943, glucagon or GLP in the full text of the 2026 list38 WADA Prohibited List 2026
• The list's class S0 covers pharmacological substances not addressed elsewhere on the list and without current approval by any government health regulator for use in humans. 38Source sentence"Any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use (e.g. drugs under pre-clinical or clinical development ...) is prohibited at all times."38 WADA Prohibited List 2026
• A 2026 paper from the LADETEC laboratory in Rio de Janeiro validated an LC-HRMS method for retatrutide in plasma and urine against WADA criteria and measured both sample types over time. 20Source sentenceAbstract, Methods: "A method based on liquid chromatography-high-resolution mass spectrometry (LC-HRMS) dedicated to monitor retatrutide was developed and validated in human plasma and urine in accordance with World Anti-Doping Agency (WADA) criteria." Blood and urine samples were collected at predefined time points20 Rapid Commun Mass Spectrom 2026

Safety alerts outside trials

• 19 June 2026, Victoria Department of Health (Australia) (Australia), alert: These toxic effects are possibly associated with a contaminant in the products labelled as ‘Retatrutide’ and all such products are at risk. TGA: laboratory test of one product sold as retatrutide, safety advisory of 14 Sep 2026 4545 Victoria Department of Health alert, 19 June 2026
• 21 May 2026, Medsafe (New Zealand) (New Zealand), advisory: Retatrutide is a potential medicine that is still being studied. It has not been approved for use by any trusted medicines regulator, apart from use in overseas clinical trials. Victoria Department of Health: alert of 19 Jun 2026 on products labelled Retatrutide 4646 Medsafe consumer advisory, 21 May 2026

Registered trials

• NCT05929066Phase 3

  Status

  TRIUMPH-1. Completed 30 Apr 2026; no results posted on the registry

  Sponsor

  Eli Lilly and Company

  Site countries

  Australia, Brazil, Canada, Hungary, India, Mexico, Poland, Puerto Rico, Romania, Spain, UK, US

  Primary endpoint

  Primary endpoints as registered

  Primary endpoint met

  met

  Last synced

  14 October 2026

• NCT05929079Phase 3

  Status

  TRIUMPH-2. Completed 16 Jun 2026; no results posted on the registry

  Sponsor

  Eli Lilly and Company

  Site countries

  Argentina, Australia, Brazil, India, Mexico, Romania, Spain, US

  Primary endpoint

  Primary endpoint at week 80, as published

  Primary endpoint met

  met

  Last synced

  14 October 2026

• NCT05882045Phase 3

  Status

  TRIUMPH-3. Completed 14 May 2026; no results posted, no paper found as of 14 Oct 2026

  Sponsor

  Eli Lilly and Company

  Site countries

  Argentina, Australia, Canada, Hungary, Mexico, Poland, Puerto Rico, Slovakia, Spain, US

  Primary endpoint

  One primary endpoint at week 80, as registered

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• NCT06354660Phase 3

  Status

  TRANSCEND-T2D-1. Completed 20 Feb 2026; no results posted on the registry

  Sponsor

  Eli Lilly and Company

  Site countries

  India, Mexico, Puerto Rico, US

  Primary endpoint

  Change in HbA1c from baseline to week 40

  Primary endpoint met

  met

  Last synced

  14 October 2026

• NCT06260722Phase 3

  Status

  TRANSCEND-T2D-2. Active, not recruiting; completion estimated Feb 2027

  Sponsor

  Eli Lilly and Company

  Site countries

  Argentina, Canada, Mexico, Puerto Rico, US

  Primary endpoint

  Change in HbA1c from baseline to week 80, compared with semaglutide

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• NCT06297603Phase 3

  Status

  TRANSCEND-T2D-3. Active, not recruiting; completion estimated Nov 2026

  Sponsor

  Eli Lilly and Company

  Site countries

  Argentina, Brazil, Israel, Mexico, Puerto Rico, UK, US

  Primary endpoint

  Change in HbA1c from baseline to week 52

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• NCT06383390Phase 3

  Status

  TRIUMPH-Outcomes. Active, not recruiting; completion estimated Feb 2029

  Sponsor

  Eli Lilly and Company

  Site countries

  Argentina, Australia, Austria, Belgium, Brazil, Canada, Czechia, Denmark, France, Germany, Greece, Hungary, India, Israel, Italy, Mexico, Netherlands, New Zealand, Poland, Puerto Rico, Romania, Slovakia, Spain, Türkiye, Ukraine, UK, US

  Primary endpoint

  Time to first composite cardiovascular event, and a composite kidney endpoint

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• NCT06662383Phase 3

  Status

  TRIUMPH-5. Active, not recruiting; primary completion estimated Nov 2026

  Sponsor

  Eli Lilly and Company

  Site countries

  Argentina, Germany, Poland, Puerto Rico, US

  Primary endpoint

  One primary endpoint at week 80, compared with tirzepatide, as registered

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• NCT06859268Phase 3

  Status

  TRIUMPH-6. Active, not recruiting; completion estimated Apr 2028

  Sponsor

  Eli Lilly and Company

  Site countries

  Canada, UK, US

  Primary endpoint

  One primary endpoint at week 116, as registered

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• NCT07035093Phase 3

  Status

  TRIUMPH-7. Active, not recruiting; completion estimated Sep 2027

  Sponsor

  Eli Lilly and Company

  Site countries

  Argentina, Canada, Poland, US

  Primary endpoint

  Pain intensity on a numeric rating scale (chronic low back pain) and a second primary endpoint, as registered

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• NCT07232719Phase 3

  Status

  TRIUMPH-8. Active, not recruiting; completion estimated Jul 2027

  Sponsor

  Eli Lilly and Company

  Site countries

  UK, US

  Primary endpoint

  One primary endpoint at week 56, as registered

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• NCT07357415Phase 3

  Status

  TRIUMPH-9. Active, not recruiting; completion estimated Nov 2028

  Sponsor

  Eli Lilly and Company

  Site countries

  Argentina, Canada, US

  Primary endpoint

  One primary endpoint at week 104, as registered

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• NCT04881760Phase 2

  Status

  Completed 22 Nov 2022; results posted on the registry

  Sponsor

  Eli Lilly and Company

  Site countries

  Puerto Rico, US

  Primary endpoint

  Primary endpoint at week 24, as registered

  Primary endpoint met

  met

  Last synced

  14 October 2026

• NCT04867785Phase 2

  Status

  Completed 27 Oct 2022; results posted on the registry

  Sponsor

  Eli Lilly and Company

  Site countries

  Puerto Rico, US

  Primary endpoint

  Change in HbA1c from baseline to 24 weeks

  Primary endpoint met

  mixed

  Last synced

  14 October 2026

• NCT05936151Phase 2

  Status

  Completed 21 Oct 2025; no results posted on the registry

  Sponsor

  Eli Lilly and Company

  Site countries

  Canada, Italy, Spain, UK, US

  Primary endpoint

  Change in measured glomerular filtration rate at week 24

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• NCT07467447Phase 2

  Status

  Recruiting; completion estimated Feb 2028

  Sponsor

  Hudson Biotech

  Site countries

  China (global context)

  Primary endpoint

  One primary endpoint at week 24, as registered

  Primary endpoint met

  not reported

  Last synced

  14 October 2026

• ClinicalTrials.gov on 14 Oct 2026: 33 records for retatrutide (14 phase 1, 4 phase 2, 14 phase 3, one expanded access record). The table lists 16 of the 18 phase 2 and phase 3 records; the other two are NCT05931367 (TRIUMPH-4, completed) and NCT07165028 (recruiting). Phase 1 records are not listed. 7,11,32Source sentencequery.intr retatrutide: totalCount 33; phases PHASE1 14, PHASE2 4, PHASE3 14, one expanded access record (status AVAILABLE, no phase); phase 3 overall status COMPLETED 5, ACTIVE_NOT_RECRUITING 8, RECRUITING 1; lead sponsor Eli Lilly and Company 32, Hudson Biotech 17 ClinicalTrials.gov search, 14 October 202611 NCT0593136732 NCT07165028
• Results are posted on ClinicalTrials.gov for two of the listed studies, both phase 2 (NCT04881760 and NCT04867785). 7,55,56Source sentencehasResults true: NCT04881760, NCT04867785; hasResults false for every phase 3 record7 ClinicalTrials.gov search, 14 October 202655 NCT0488176056 NCT04867785
• Two phase 2 rows derive their state from the results posted on the registry: NCT04881760 is marked met and NCT04867785 is marked mixed, from the six primary comparisons each record posts. 56,55Source sentenceRegistry results section of each record, primary outcome statistical analyses, six comparisons per study, read 14 Oct 2026: NCT04881760 met in all six; NCT04867785 met in five of six and not met in one56 NCT0486778555 NCT04881760

Timeline

1. 18 August 2022Discovery paper describes LY3437943 as a triple agonist at the glucagon, GIP and GLP-1 receptors 5Source sentenceCell Metab, published online 18 Aug 20225 Cell Metab 2022
2. 27 October 2022Phase 1b randomised trial (NCT04143802) published 33Source sentenceLancet, published online 27 Oct 2022; "phase 1b, proof-of-concept, double-blind, placebo-controlled, randomised"33 Lancet 2022
3. 26 June 2023Phase 2 randomised trials published in NEJM and The Lancet 26,34Source sentenceN Engl J Med and Lancet, both published online 26 Jun 202326 N Engl J Med 202334 Lancet 2023
4. 10 July 2023TRIUMPH-1 phase 3 trial starts 47Source sentenceStudy start 2023-07-10 (ACTUAL)47 NCT05929066
5. 10 June 2024Phase 2a substudy in metabolic dysfunction-associated steatotic liver disease published 35Source sentenceNat Med, published online 10 Jun 202435 Nat Med 2024
6. 6 June 2026Phase 3 trial NCT06354660 published in The Lancet 9Source sentenceLancet, published online 6 Jun 2026; registered NCT063546609 Lancet 2026, NCT06354660
7. September 2026Letter reports laboratory tests of three products sold as retatrutide in Australia 14Source sentenceDrug Alcohol Rev 2026 Sep;45(6):e70231 (PubMed publication date 2026 Sep)14 Drug Alcohol Rev 2026
8. 14 September 2026TGA laboratory finds semaglutide and no retatrutide in one product sold as retatrutide 16Source sentencePublished 14 September 202616 TGA safety advisory, 14 September 2026
9. 29 September 2026TRIUMPH-1 and TRIUMPH-2 phase 3 papers published 8,1Source sentenceN Engl J Med, 29 Sep 2026 (TRIUMPH-1); Lancet, published online 29 Sep 2026 (TRIUMPH-2)8 N Engl J Med 2026, TRIUMPH-11 Lancet 2026, TRIUMPH-2

Integrity notes

• PubMed CommentsCorrections was checked on 14 Oct 2026 for the studies on this page, and PubMed holds no retatrutide record typed as a retracted publication, expression of concern or published erratum. 6Source sentenceCommentsCorrections: no Retraction, Erratum or ExpressionOfConcern entries for the 15 studies; (retatrutide[tiab] OR "LY3437943"[tiab]) AND (retracted publication[pt] OR expression of concern[pt] OR published erratum[pt]): 0 records6 PubMed search for retatrutide and LY3437943, 14 October 2026
• PubMed links published comments to three trial papers: three to the 2023 NEJM phase 2 paper and one each to the 2023 Lancet phase 2 paper and the 2022 phase 1b paper. 26,34,33Source sentenceCommentIn: 37888925, 37888926, 37888927 (37366315); 37385276 (37385280); 36436519 (36354040)26 N Engl J Med 202334 Lancet 202333 Lancet 2022
• TRIUMPH-1 counts differ by source: ClinicalTrials.gov gives an actual enrollment of 2,335, while the NEJM abstract reports 2,339 participants randomised. 47,8Source sentenceNCT05929066 enrollmentInfo: count 2335, type ACTUAL. PMID 42814954, Results: "A total of 2339 participants underwent randomization."47 NCT059290668 N Engl J Med 2026, TRIUMPH-1
• A 2026 post hoc analysis of the two phase 2 trials (NCT04881760 and NCT04867785) measured lipoprotein and inflammatory biomarkers; its authors include Lilly employees. 58Source sentenceAbstract, Aims: "lipoprotein and inflammatory biomarkers were assessed post hoc in phase 2 trials"; trial registration NCT04881760 and NCT04867785; COI: authors "are (or were at the time this research was conducted) employees and shareholders of Eli Lilly and Company"58 Ruotolo et al. 2026

Related

• Products sold as retatrutide: label content testing, Australia→
• TGA test: product sold as retatrutide contained semaglutide→
• Semaglutide in the research library→
• Tirzepatide in the research library→
• Tirzepatide and retatrutide compared→
• GLP-1, GIP and glucagon receptors→
• How to read a certificate of analysis→
• Glossary of terms on this page→

Related in this edition

US

• FDA warning letters of 24 August 2026→

Chemistry and records

Retatrutide: sequence, mass, CAS and regulatory record in the research library →

Sources

1. 1Lancet 2026, TRIUMPH-2 accessed 14 Oct 2026
2. 2GSRS substance record, UNII NOP2Y096GV accessed 14 Oct 2026
3. 3PubChem CID 171390338 accessed 14 Oct 2026
4. 4Eli Lilly and Company news release, 12 August 2026 accessed 14 Oct 2026
5. 5Cell Metab 2022 accessed 14 Oct 2026
6. 6PubMed search for retatrutide and LY3437943, 14 October 2026 accessed 14 Oct 2026
7. 7ClinicalTrials.gov search, 14 October 2026 accessed 14 Oct 2026
8. 8N Engl J Med 2026, TRIUMPH-1 accessed 14 Oct 2026
9. 9Lancet 2026, NCT06354660 accessed 14 Oct 2026
10. 10NCT05882045 accessed 14 Oct 2026
11. 11NCT05931367 accessed 14 Oct 2026
12. 12NCT06662383 accessed 14 Oct 2026
13. 13NCT06383390 accessed 14 Oct 2026
14. 14Drug Alcohol Rev 2026 accessed 14 Oct 2026
15. 15PMC full text of the 2026 letter (PMID 42559975) accessed 14 Oct 2026
16. 16TGA safety advisory, 14 September 2026 accessed 14 Oct 2026
17. 17Peptency catalog chemistry record, retatrutide accessed 14 Oct 2026
18. 18GSRS name search for retatrutide, 14 October 2026 accessed 14 Oct 2026
19. 19PubChem CID 56843331 accessed 14 Oct 2026
20. 20Rapid Commun Mass Spectrom 2026 accessed 14 Oct 2026
21. 21PubMed search for GLP-3 with retatrutide, 14 October 2026 accessed 14 Oct 2026
22. 22Naunyn Schmiedebergs Arch Pharmacol 2025 accessed 14 Oct 2026
23. 23iScience 2026 accessed 14 Oct 2026
24. 24Am J Physiol Gastrointest Liver Physiol 2025 accessed 14 Oct 2026
25. 25Behav Brain Res 2026 accessed 14 Oct 2026
26. 26N Engl J Med 2023 accessed 14 Oct 2026
27. 27openFDA Drugs@FDA query for retatrutide, 14 October 2026 accessed 14 Oct 2026
28. 28FDA warning letter 695156 (Prime Vitality Inc), 10 December 2024 accessed 14 Oct 2026
29. 29FDA warning letter 721806 (Gram Peptides), 31 March 2026 accessed 14 Oct 2026
30. 30FDA warning letter 734884 (Royal Peptides LLC), 24 August 2026 accessed 14 Oct 2026
31. 31NCT06297603 accessed 14 Oct 2026
32. 32NCT07165028 accessed 14 Oct 2026
33. 33Lancet 2022 accessed 14 Oct 2026
34. 34Lancet 2023 accessed 14 Oct 2026
35. 35Nat Med 2024 accessed 14 Oct 2026
36. 36Endocrine 2025 accessed 14 Oct 2026
37. 37NCT07467447 accessed 14 Oct 2026
38. 38WADA Prohibited List 2026 accessed 14 Oct 2026
39. 39FDA warning letter 735063 (Peptide Partners LLC), 24 August 2026 accessed 14 Oct 2026
40. 40FDA warning letter 735067 (TXP Innovations LLC dba Tex Peptides), 24 August 2026 accessed 14 Oct 2026
41. 41FDA warning letter 733652 (NuScience Peptides LLC), 24 August 2026 accessed 14 Oct 2026
42. 42FDA warning letter 735127 (Peak Performance Peptides), 24 August 2026 accessed 14 Oct 2026
43. 43FDA Import Alert 66-80, published date 21 September 2026 accessed 14 Oct 2026
44. 44Public Citizen report, 16 June 2026 accessed 14 Oct 2026
45. 45Victoria Department of Health alert, 19 June 2026 accessed 14 Oct 2026
46. 46Medsafe consumer advisory, 21 May 2026 accessed 14 Oct 2026
47. 47NCT05929066 accessed 14 Oct 2026
48. 48NCT05929079 accessed 14 Oct 2026
49. 49NCT06354660 accessed 14 Oct 2026
50. 50NCT06260722 accessed 14 Oct 2026
51. 51NCT06859268 accessed 14 Oct 2026
52. 52NCT07035093 accessed 14 Oct 2026
53. 53NCT07232719 accessed 14 Oct 2026
54. 54NCT07357415 accessed 14 Oct 2026
55. 55NCT04881760 accessed 14 Oct 2026
56. 56NCT04867785 accessed 14 Oct 2026
57. 57NCT05936151 accessed 14 Oct 2026
58. 58Ruotolo et al. 2026 accessed 14 Oct 2026

About this page

Research-use information. This library summarises published literature and regulator records. It is not guidance for use, not medical advice, and not a statement that any material is suitable for use in people or animals.

Reviewed by the Peptency editorial process. Version 1, last edited 14 October 2026, 58 sources.

Cite this page: Peptency Academy. Retatrutide (LY3437943): chemistry, trials and regulator records. Version 1./us/academy/compounds/retatrutide/