The purpose of this study is to evaluate how well LY4088044 is tolerated and what side effects may occur in healthy participants. The study drug will be administered either subcutaneously (SC) (under the skin) or intravenously (IV) (into a vein in the arm). Blood tests will be performed to check how much LY4088044 gets into the bloodstream and how long it takes the body to eliminate it. The study will last up to approximately 92 weeks for Parts A, B, and C, excluding screening.