The purpose of this Master Protocol is to support two studies to see how well and how safely orforglipron works compared to placebo in participants who have obesity or overweight with or without type 2 diabetes. Participants will be screened for about 4 weeks, after which they will enroll into either J2A-MC-GZP1, NCT06972459 (do not have type 2 diabetes) or J2A-MC-GZP2, NCT06972472 (have type 2 diabetes).