The main purpose of this study is to understand how safe and well-tolerated LY4174794 is in participants with obesity or overweight who are otherwise healthy. Blood tests will be performed to check how much LY4174794 gets into the bloodstream and how long it takes the body to eliminate it.

Participation in this study will last about 35 to 45 weeks (7 to 11 months).

Inclusion Criteria:

• Are overtly healthy with no comorbidities related to body mass index (BMI), such as type 2 diabetes mellitus or unstable cardiovascular disease
• Are overweight with a BMI of ≥27 kilogram per meter square (kg/m²), or have obesity with a BMI of ≥30 kg/ m²
• Have had a self-reported stable weight for 3 months prior to screening

Exclusion Criteria:

• Have a history or presence of cardiovascular, respiratory, hepatic, renal, 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 intervention, or of interfering with the interpretation of data
• Is an individual of childbearing potential (IOCBP)