The purpose of this study is to investigate the efficacy and safety of different retatrutide dose escalation schemes in participants without type 2 diabetes who have obesity or overweight. Participation in the study will last about 113 weeks.

Inclusion Criteria:

• Have a Body Mass Index (BMI) at screening

  • ≥ 30 kilogram per square meter (kg/m2) OR
  • ≥ 27 kg/m2 with presence of at least one of the following weight-related conditions at screening: 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 kilograms (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:

  • heart attack
  • stroke
  • hospitalization for unstable angina or 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

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.

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.

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