A Study of Retatrutide (LY3437943) in Participants With Obesity or Overweight (TRIUMPH-8)

April 16, 2026 updated by: Eli Lilly and Company

A Phase 3b Study to Investigate the Efficacy and Safety of Retatrutide Once Weekly in Participants Without Type 2 Diabetes Who Have Obesity or Overweight: A Randomized, Double-Blind, Placebo-Controlled Trial

The purpose of this study is to evaluate the efficacy and safety of retatrutide compared with placebo for body weight reduction.

Participation in the study will last about 65 weeks and may include about 18 visits.

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.
250

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: Trial questions or participation questions: 1-877-CTLILLY (1-877-285-4559) or
  • Phone Number: 1-317-615-4559
  • Email: LillyTrials@Lilly.com

Study Contact Backup

Study Locations

  • United Kingdom
      • Birmingham, United Kingdom, B21 9RY
        • FutureMeds - Birmingham
      • Blackpool, United Kingdom, FY3 7EN
        • Layton Medical Centre
      • Bradford-on-Avon, United Kingdom, BA15 1DQ
        • Bradford on Avon Health Centre
      • Bromborough, United Kingdom, CH62 6EE
        • FutureMeds - Liverpool
      • Cheadle, United Kingdom, ST10 1NS
        • Cheadle Community Hospital
      • Hounslow, United Kingdom, TW4 7NR
        • HMC Health Group - Meadows Centre for Health
      • Oxford, United Kingdom, OX4 1XB
        • St Bartholomew's Medical Centre
      • Penzance, United Kingdom, TR18 3DX
        • Atlantic Medical
      • Poole, United Kingdom, BH16 5PW
        • The Adam Practice
      • Rotherham, United Kingdom, S61 1AH
        • Woodstock Bower Surgery
      • Torpoint, United Kingdom, PL11 2TB
        • Rame Group Practice
      • Wellingborough, United Kingdom, NN8 4RW
        • Albany House Medical Centre
  • United States
    • California
      • Riverside, California, United States, 92503
        • Artemis Institute for Clinical Research
    • Florida
      • Atlantis, Florida, United States, 33462
        • JEM Research Institute
      • Orlando, Florida, United States, 32806
        • Headlands Research Orlando
      • Tamarac, Florida, United States, 33321
        • Care Access - Tamarac
    • Illinois
      • Arlington Heights, Illinois, United States, 60005
        • Care Access - Arlington Heights
    • Kentucky
      • Louisville, Kentucky, United States, 40213
        • L-MARC Research Center
    • Louisiana
      • Monroe, Louisiana, United States, 71201
        • IMA Clinical Research Monroe - Armand
    • Maryland
      • Baltimore, Maryland, United States, 21208
        • Pharmasite Research, Inc.
    • Missouri
      • Chesterfield, Missouri, United States, 63005
        • Clinical Research Professionals
      • Springfield, Missouri, United States, 65807
        • Clinvest Headlands Llc
    • New Jersey
      • Warren Township, New Jersey, United States, 07059
        • IMA Clinical Research Warren
    • New York
      • New York, New York, United States, 10036
        • IMA Clinical Research Manhattan
    • North Carolina
      • Wilmington, North Carolina, United States, 28403
        • Trial Management Associates - Wilmington - Floral Parkway
    • Texas
      • Dallas, Texas, United States, 75251
        • Cedar Health Research
      • El Paso, Texas, United States, 79902
        • Headlands Research-El Paso
      • Euless, Texas, United States, 76040
        • Cedar Health Research - Euless
      • Fort Worth, Texas, United States, 76132
        • Cedar Health Research - Fort Worth
      • Houston, Texas, United States, 77054
        • Care Access - Houston
      • San Antonio, Texas, United States, 78229
        • IMA Clinical Research San Antonio

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 a body mass index (BMI) of:

    • ≥30 kilogram per square meter (kg/m2) OR
    • ≥27 kg/m2 with at least one of the following weight-related conditions: high blood pressure, abnormal levels of lipid, obstructive sleep apnea, heart disease
  • Have at least one unsuccessful attempt to lose weight by dieting

Exclusion Criteria:

  • Have a self-reported change in body weight >5 kg (11 pounds) within 90 days before screening
  • Have a prior or planned surgical treatment for obesity
  • Have type 1 diabetes or type 2 diabetes
  • 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)
    • 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
  • Have taken weight loss drugs, including over-the counter medications within 90 days prior to screening

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.
Placebo Comparator: Placebo
Participants will receive placebo SC
Drug: Placebo
Administered SC
Experimental: Retatrutide Dose 1
Participants will receive retatrutide subcutaneously (SC)
Drug: Retatrutide
Administered SC
Other Names:
  • LY3437943
Experimental: Retatrutide Dose 2
Participants will receive retatrutide SC
Drug: Retatrutide
Administered SC
Other Names:
  • LY3437943

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 56
Baseline, Week 56

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 Systolic Blood Pressure
Time Frame: Baseline, Week 56
Baseline, Week 56
Change from Baseline in Waist Circumference
Time Frame: Baseline, Week 56
Baseline, Week 56
Percent Change from Baseline in Non-High-Density Lipoprotein (HDL) Cholesterol
Time Frame: Baseline, Week 56
Baseline, Week 56
Pharmacokinetics (PK): Steady State Area Under the Concentration Time Curve (AUC)
Time Frame: Baseline through Week 56
Baseline through Week 56

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 8 AM - 8 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 17, 2025

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.
July 1, 2027

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.
July 1, 2027

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).
November 14, 2025

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.
November 14, 2025

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.
November 18, 2025

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.
April 17, 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.
April 16, 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.
April 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.
  • 27769
  • J1I-MC-GZQJ (Other Identifier: Eli Lilly and Company)

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 or 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 should be approved by an independent review panel and researchers should 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

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.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings