A Study of LY3875383 in Healthy Participants and Participants With Hypertriglyceridemia

Inclusion Criteria: All participants: * Have a body mass index (BMI) between 18.5 and 40 kilograms per square meter (kg/m²), inclusive. * Males who agree to follow contraceptive requirements, or women not of childbearing potential (WNOCBP). Healthy participants (Part A): • Participants must be overtly healthy, as determined by medical evaluation. For Part B: • Participants must be first-generation Japanese, defined as the participant's biological parents, and all of the participant's biological grandparents must be of exclusive Japanese descent and born in Japan. Hypertriglyceridemia participants (Parts C and D): For Part C: * Have history of very high triglyceride (lipid) level 500 mg/dL ≤ TG \<2000 mg/dL, which needs to be further confirmed at screening. * Participants must be on a lipid-modifying diet and can be on stable lipid-lowering drugs (LLDs) for at least 8 weeks before screening and plan to continue the same throughout the study duration. For Part D: * Have history of high triglyceride (lipid) level between 150 mg/dL and 500 mg/dL inclusive at pre-screening or based on medical history and confirmed at screening and Low-density lipoprotein cholesterol (LDL-C) level of ≥40 mg/dL. * Participants must be on a stable moderate or high-intensity dose of a statin for at least 8 weeks before screening and plan to continue the same medication and dose throughout the study duration. Exclusion Criteria: All participants: * Participants must not be currently participating in or completed a clinical trial within the last 30 days * Have donated blood of more than 500 mL within the previous 3 months * Have one of the following viral infections: hepatitis B virus, hepatitis C virus or human immunodeficiency virus (HIV). * Participants must not be heavy alcohol drinkers or cigarette smokers. For Part C: Have active pancreatitis within the last 6 months