The main purpose of this study is to assess the safety and tolerability of LY4515100 when given orally to healthy participants. LY4515100 will be given by itself or with other medicines. Blood tests will be performed to investigate how the body processes the study drug and how the study drug affects the body. The study will have 3 parts and will last about 50 days. For each participant in Part A, the study will include a stay in the Clinical Research Unit (CRU) lasting about 6 days. For each participant in Part B, the study will include a stay in the CRU lasting about 15 days. For each participant in Part C, the study will include up to 2 stays in the CRU each lasting between 7-28 days.