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

NCT06662383 · Active, not recruiting

Last updated 2026-05-28

This clinical trial is testing the effects of the medication retatrutide compared to tirzepatide in adults who have obesity.

Status Active, not recruiting Ongoing, but no longer enrolling new participants.

Phase Phase 3 Confirms effectiveness in a large group before approval.

Type Interventional (clinical trial)

Design Randomized, double-blind treatment study

Participants 800 people Planned (estimated).

Who can join Ages 18+ · all sexes

Timeline Started 2024-11 · est. completion 2026-12

Where 65 sites · Argentina, Germany, Poland, Puerto Rico, United States

What this study is testing ClinicalTrials.gov NCT06662383 ↗

Description as written by the study sponsor.

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.

Treatments tested

Retatrutide also known as LY3437943 Drug

Administered SC
Tirzepatide also known as LY3298176 Drug

Administered SC

Main thing measured	Percent Change from Baseline in Body Weight
Sponsor	Eli Lilly and Company
Conditions studied	Obesity
GLP-1 drugs	tirzepatide, retatrutide

Full protocol, eligibility, and contacts on ClinicalTrials.gov NCT06662383 ↗