A Study of Retatrutide (LY3437943) Compared to Tirzepatide (LY3298176) in Adults Who Have Obesity (TRIUMPH-5)

July 17, 2026 updated by: Eli Lilly and Company

A Phase 3, Randomized, Double-Blind Study to Evaluate the Efficacy and Safety of Retatrutide Compared to Tirzepatide in Adults Who Have Obesity

The main purpose of this study is to evaluate the efficacy and safety of retatrutide compared to tirzepatide in adults who have obesity. The study will last about 89 weeks.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
800

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: There may be multiple sites in this clinical trial. 1-877-CTLILLY (1-877-285-4559) or
  • Phone Number: 1-317-615-4559
  • Email: clinical_inquiry_hub@lilly.com

Study Locations

  • Argentina
      • Buenos Aires, Argentina, C1056ABI
        • Centro de Investigaciones Metabolicas (CINME)
    • Buenos Aires
      • Ramos Mejía, Buenos Aires, Argentina, B1704ETD
        • DIM Clinica Privada
    • Buenos Aires F.D.
      • Buenos Aires, Buenos Aires F.D., Argentina, C1120AAC
        • Centro Medico Viamonte
      • Buenos Aires, Buenos Aires F.D., Argentina, C1425AGC
        • Centro Medico Dra. Laura Maffei- Investigacion Clinica Aplicada
      • Buenos Aires, Buenos Aires F.D., Argentina, C1405BUB
        • Consultorio de Investigacion Clinica EMO SRL
  • Germany
      • Hamburg, Germany, 22607
        • Diabeteszentrum Hamburg West
      • Hamburg, Germany, 21109
        • Diabetes Zentrum Wilhelmsburg
    • Baden-Wurttemberg
      • Villingen-Schwenningen, Baden-Wurttemberg, Germany, 78048
        • Gemeinschaftspraxis Prof. Dr. med. Stephan Jacob, Dr. med. Frohmut Jacob
    • Lower Saxony
      • Lingen, Lower Saxony, Germany, 49808
        • Diabetologische Schwerpunktpraxis Dr. Staudenmeyer & Dr. Schiwietz
    • North Rhine-Westphalia
      • Cologne, North Rhine-Westphalia, Germany, 51069
        • Zentrum fur klinische Forschung - Köln
      • Essen, North Rhine-Westphalia, Germany, 45355
        • Medizentrum Essen Borbeck
      • Essen, North Rhine-Westphalia, Germany, 45136
        • InnoDiab Forschung GmbH
    • Saxony
      • Leipzig, Saxony, Germany, 04107
        • AmBeNet GmbH
    • Schleswig-Holstein
      • Oldenburg in Holstein, Schleswig-Holstein, Germany, 23758
        • Red-Institut GmbH
  • Poland
    • Greater Poland Voivodeship
      • Poznan, Greater Poland Voivodeship, Poland, 61-853
        • Nzoz Neuro-Kard Ilkowski i Partnerzy SPL
      • Poznan, Greater Poland Voivodeship, Poland, 60-589
        • Centrum Zdrowia Metabolicznego Pawel Bogdanski
    • Lublin Voivodeship
      • Lublin, Lublin Voivodeship, Poland, 20-718
        • Ekamed
      • Lublin, Lublin Voivodeship, Poland, 20-333
        • Gabinety TERPA
    • Podlaskie Voivodeship
      • Bialystok, Podlaskie Voivodeship, Poland, 15-351
        • Zdrowie Osteo-Medic
      • Bialystok, Podlaskie Voivodeship, Poland, 15-276
        • Uniwersytecki Szpital Kliniczny w Białymstoku
      • Bialystok, Podlaskie Voivodeship, Poland, 15-281
        • Gabinet Leczenia Otylosci i Chorob Dietozaleznych - dr hab. n. med. Lucyna Ostrowska
      • Bialystok, Podlaskie Voivodeship, Poland, 15-435
        • NZOZ Specjalistyczny Ośrodek Internistyczno-Diabetologiczny
    • Silesian Voivodeship
      • Ruda Śląska, Silesian Voivodeship, Poland, 41-709
        • NZOZ Przychodnia Specjalistyczna Andrzej Wittek, Henryk Rudzki
    • Łódź Voivodeship
      • Lodz, Łódź Voivodeship, Poland, 90-338
        • Centrum Terapii Wspolczesnej J. M. Jasnorzewska Spolka Komandytowo-Akcyjna
  • Puerto Rico
      • Ponce, Puerto Rico, 00716
        • Ponce Medical School Foundation Inc.
  • United States
    • Arizona
      • Tempe, Arizona, United States, 85283
        • Medical Advancement Centers of Arizona
    • California
      • Newport Beach, California, United States, 92663
        • Mary & Dick Allen Diabetes Center
      • San Diego, California, United States, 92103
        • Artemis Institute for Clinical Research
      • Spring Valley, California, United States, 91978
        • Encompass Clinical Research
      • Walnut Creek, California, United States, 94598
        • Diablo Clinical Research, Inc.
    • Colorado
      • Aurora, Colorado, United States, 80012
        • Lynn Institute of Denver
    • Connecticut
      • Bridgeport, Connecticut, United States, 06610
        • Bridgeport Hospital
      • New Haven, Connecticut, United States, 06519
        • Yale University School Of Medicine
    • Florida
      • Hollywood, Florida, United States, 33024
        • Encore Medical Research
      • Miami, Florida, United States, 33135
        • Suncoast Research Group
      • Miami, Florida, United States, 33186
        • Onhealth Research Center
      • Sunrise, Florida, United States, 33351
        • Precision Clinical Research
      • Vero Beach, Florida, United States, 32960
        • Einstein Clinical Research
    • Georgia
      • Columbus, Georgia, United States, 31904
        • ClinCept Clinical Research - MH
      • Gainesville, Georgia, United States, 30501
        • Northeast Georgia Medical Center
      • Stonecrest, Georgia, United States, 30038
        • Pivotal Research Solutions
    • Hawaii
      • Honolulu, Hawaii, United States, 96814
        • East-West Medical Research Institute
    • Illinois
      • Chicago, Illinois, United States, 60611
        • Northwestern University
    • Iowa
      • West Des Moines, Iowa, United States, 50265
        • Integrated Clinical Trial Services, Inc.
    • Louisiana
      • Baton Rouge, Louisiana, United States, 70808
        • Pennington Biomedical Research Center
    • Michigan
      • Bay City, Michigan, United States, 48706
        • Great Lakes Research Group, Inc.
      • Southfield, Michigan, United States, 48075
        • Great Lakes Research Institute
    • Missouri
      • City of Saint Peters, Missouri, United States, 63303
        • StudyMetrix Research
    • Nevada
      • Henderson, Nevada, United States, 89074
        • Las Vegas Endocrinology
    • New York
      • Albany, New York, United States, 12203
        • Albany Medical College, Division of Community Endocrinology
      • New York, New York, United States, 10075
        • New York Gastroenterology Associates
      • Valhalla, New York, United States, 10595
        • Westchester Medical Center
    • North Carolina
      • Greensboro, North Carolina, United States, 27408
        • PharmQuest Life Sciences, LLC
      • Monroe, North Carolina, United States, 28112
        • Monroe Biomedical Research
      • Wilmington, North Carolina, United States, 28401
        • Accellacare - Wilmington
    • North Dakota
      • Fargo, North Dakota, United States, 58104
        • Lillestol Research
    • Ohio
      • Dayton, Ohio, United States, 45429
        • PriMed Clinical Research
    • South Carolina
      • Greenville, South Carolina, United States, 29607
        • Tribe Clinical Research, LLC
    • Tennessee
      • Chattanooga, Tennessee, United States, 37421
        • WR-ClinSearch, LLC
    • Texas
      • Brownsville, Texas, United States, 78526
        • Headlands Horizons LLC
      • Houston, Texas, United States, 77057
        • Next Level Urgent Care
      • Houston, Texas, United States, 77079
        • Houston Research Institute
      • Shavano Park, Texas, United States, 78231
        • Consano Clinical Research, LLC
    • Utah
      • St. George, Utah, United States, 84790
        • Chrysalis Clinical Research
    • Virginia
      • Charlottesville, Virginia, United States, 22911
        • Charlottesville Medical Research

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Have obesity and a history of at least one self-reported unsuccessful dietary effort to reduce body weight.

Exclusion Criteria:

  • Have a self-reported change in body weight >5 kilograms (kg) (11 pounds) within 90 days before screening.
  • Have a prior or planned surgical treatment for obesity.
  • Have a prior or planned endoscopic procedure and/or device-based therapy for obesity.
  • Have taken weight loss drugs, including over-the-counter medications, within 90 days prior to screening.
  • Have a family or personal history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia syndrome type 2 (MEN-2).

  • Have had within the past 90 days before screening:

    • acute myocardial infarction
    • cerebrovascular accident (stroke)
    • coronary revascularization
    • hospitalization for unstable angina, or
    • hospitalization due to congestive heart failure.
  • Have New York Heart Association Functional Classification Class IV congestive heart failure.
  • Have a history of chronic or acute pancreatitis.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Retatrutide
Participants will receive retatrutide administered subcutaneously (SC)
Drug: Retatrutide
Administered SC
Other Names:
  • LY3437943
Active Comparator: Tirzepatide
Participants will receive tirzepatide administered SC
Drug: Tirzepatide
Administered SC
Other Names:
  • LY3298176

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Percent Change from Baseline in Body Weight
Time Frame: Baseline, Week 80
Baseline, Week 80

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Change from Baseline in Body Mass Index (BMI)
Time Frame: Baseline, Week 80
Baseline, Week 80
Change from Baseline in Waist Circumference
Time Frame: Baseline, Week 80
Baseline, Week 80
Percent Change from Baseline in Total Cholesterol
Time Frame: Baseline, Week 80
Baseline, Week 80
Percent Change from Baseline in Triglycerides
Time Frame: Baseline, Week 80
Baseline, Week 80
Change from Baseline in Systolic Blood Pressure (SBP)
Time Frame: Baseline, Week 80
Baseline, Week 80
Change from Baseline in Diastolic Blood Pressure (DBP)
Time Frame: Baseline, Week 80
Baseline, Week 80
Change from Baseline in Hemoglobin A1c (HbA1c)
Time Frame: Baseline, Week 80
Baseline, Week 80
Percent Change from Baseline in Fasting Insulin
Time Frame: Baseline, Week 80
Baseline, Week 80
Change from Baseline in Impact of Weight on Quality of Life-Lite Clinical Trials Version (IWQOL-Lite-CT)
Time Frame: Baseline, Week 80
Baseline, Week 80

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Eli Lilly and Company

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Call 1-877-CTLILLY (1-877-285-4559) or 1-317-615-4559 Mon - Fri 9 AM - 5 PM Eastern time (UTC/GMT - 5 hours, EST), Eli Lilly and Company

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 1, 2024

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
October 25, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 25, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
October 28, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 20, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 17, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 18585
  • J1I-MC-GZBP (Other Identifier: Eli Lilly and Company)
  • 2024-511450-49-00 (Ctis)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Anonymized individual patient level data will be provided in a secure access environment upon approval of a research proposal and a signed data sharing agreement.

IPD Sharing Time Frame

Data are available 6 months after the primary publication and approval of the indication studied in the US and EU, whichever is later. Data will be indefinitely available for requesting.

IPD Sharing Access Criteria

A research proposal must be approved by an independent review panel and researchers must sign a data sharing agreement.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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