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

What Was Tested

In this phase 3 trial, researchers set out to test Retatrutide.

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

It had three arms (groups): one (experimental), one (experimental) and Placebo (placebo comparator).

Participants will receive retatrutide subcutaneously (SC).

Participants will receive retatrutide SC.

Participants will receive placebo SC.

The registry classes the interventions as drug.

Who Took Part

Enrollment: 250 planned participants were the target.

It was open to people of any sex aged from 18 years with no upper age limit.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: 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.

The full record lists 4 inclusion and 12 exclusion criteria; among the exclusions: 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.

How the Study Was Run

Design: randomized, parallel-group and double-blind.

Random assignment meant chance, not the researchers, decided who got Retatrutide and who got the comparison, which limits bias.

The Retatrutide group and the comparison group ran side by side rather than switching.

As a double-blind Retatrutide study, the assignments were hidden from both participants and investigators until the end.

Those kept unaware of assignments: participant and investigator.

It started in 2025-11-17 with completion listed for 2027-07.

It ran at 31 sites in United States (19) and United Kingdom (12).

Its stated primary purpose is treatment.

What Was Measured

Primary outcome: Percent Change from Baseline in Body Weight (time frame: Baseline, Week 56).

It also tracked 4 secondary outcomes, for example Change from Baseline in Systolic Blood Pressure, Change from Baseline in Waist Circumference and Percent Change from Baseline in Non-High-Density Lipoprotein (HDL) Cholesterol.

What This Means in Plain Language

Put simply, this is a phase 3, randomized trial of Retatrutide in 250 people.

Its status is active not recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Retatrutide compound page, all human trials.