A Study of LY3437943 in Participants With Type 2 Diabetes Mellitus (T2DM)

Inclusion Criteria: * Have T2DM for at least 3 months before screening and are without advanced known possible complications of diabetes mellitus * Have a glycated hemoglobin (HbA1c) value at lead-in and screening of ≥7.0% and ≤10.5% and treated with diet and exercise alone or a stable dose of metformin for at least 3 months prior to screening * Have had a stable body weight for the 3 months prior to randomization (\<5% body weight change) * Have a body mass index of 23 to 50 kilograms per square meter (kg/m²), inclusive * Male participants agree to use an effective method of contraception for the duration of the study plus 90 days, which corresponds to 4 months after the last investigational product dose * Women not of childbearing potential may participate and include those who are: infertile due to surgical sterilization (hysterectomy, bilateral oophorectomy, or tubal ligation), congenital anomaly such as mullerian agenesis; or those who are postmenopausal Exclusion Criteria: * Have type 1 diabetes mellitus or latent autoimmune diabetes in adults * Have uncontrolled diabetes, defined as an episode of ketoacidosis or hyperosmolar state requiring hospitalization in the 6 months prior to screening * Have a known clinically significant gastric emptying abnormality * Have had an episode of severe hypoglycemia * Have a history of acute or chronic pancreatitis or fasting serum triglyceride level of \>500 milligrams per deciliter (mg/dL) at screening and/or Day-2. If participant is on lipid-lowering therapies, doses must be stable for 30 days prior to screening * Have known liver disease, obvious clinical signs or symptoms of liver disease, acute or chronic hepatitis, or have elevations in aminotransferases (alanine aminotransferase \[ALT\] and aspartate aminotransferase \[AST\]) greater than 3X upper limit of normal (ULN) at screening and/or Day -2