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 Type 1 Diabetes, Type 2 Diabetes, or any other type of 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

A Study of Retatrutide (LY3437943) in the Maintenance of Weight Reduction in Individuals With Obesity