A Study of Tirzepatide (LY3298176) in Participants With Nonalcoholic Steatohepatitis (NASH)

* Participants must have a body mass index (BMI) ≥27 kilograms per square meter (kg/m²) and ≤50 kg/m² with stable body weight for at least 3 months * Participants with or without type 2 diabetes mellitus (T2DM) * If with T2DM, hemoglobin A1c (HbA1c) ≤9.5% * Participants must be willing to undergo baseline and endpoint liver biopsies * Participants must have histologic diagnosis of NASH with stage 2 or 3 fibrosis by liver biopsy * Participants must not have known or suspected alcohol abuse (\>14 units/week for women and \>21 units/week for men) or active substance abuse * Participants must not have evidence of cirrhosis or other forms of liver disease * Participants must not have heart attack, stroke, or hospitalization for congestive heart failure in the past 6 months * Participants must not have active cancer within the last 5 years * Participants must not have uncontrolled high blood pressure * Participants must not have renal impairment with estimated glomerular filtration rate (eGFR) \<30 milliters/minute/1.73m²; for participants on metformin, eGFR \<45 mL/min/1.73m² * Participants must not have a diagnosis of type 1 diabetes * Participants must not have a history of pancreatitis (acute or chronic) * Participants must not have calcitonin ≥35 nanograms per liter * Participant must not have family or personal history of multiple endocrine neoplasia type 2 or medullary thyroid carcinoma (family is defined as a first degree relative) * Female participants must not be pregnant, breast-feeding, or intend to become pregnant or of childbearing potential and not using adequate contraceptive method (adequate contraceptive measures as required by local regulation or practice)