The purpose of this study is to look at how safe and well-tolerated LY4167586 is in participants with obesity or overweight who are otherwise healthy. Blood tests will be performed to check how much LY4167586 gets into the bloodstream and how long it takes the body to eliminate it following a single administration. Participation in the study will last approximately 7 months.

Inclusion Criteria:

• Participant must be 21 for Singapore site
• Have a body mass index (BMI) between 27.0 kilogram per square meter (kg/m²) and 35.0 kg/m², inclusive
• Have had a self-reported stable weight for 3 months prior to screening (less than approximately 5 percent [%] body weight change)

Exclusion Criteria:

• Have a history or presence of cardiovascular, respiratory, hepatic, renal, gastrointestinal (GI), endocrine, hematological, or neurological disorders capable of significantly altering the absorption, metabolism, or elimination of drugs, or of constituting a risk when taking the study drug, or of interfering with the interpretation of data.
• Is an individual of childbearing potential (IOCBP)