A Study to Learn How the Study Medicine Called PF-08653945 is Taken up Into the Blood in Adults With Overweight or Obesity

Inclusion Criteria: * Participants 18 years of age or older at Screening who are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, and ECGs. * BMI of 27-45 kg/m2; and a total body weight \>50 kg (110 lb). * For Japanese participants (Optional Cohort 2) only: BMI of 22-45 kg/m2 and a total body weight \>50 kg (110 lb). NOTE: Participants enrolling as Japanese must have 4 biological Japanese grandparents who were born in Japan. Exclusion Criteria: * Pregnant or breastfeeding women, or those planning pregnancy during the study. * Clinically significant medical conditions including hematologic, renal, endocrine, pulmonary, gastrointestinal (including pancreatitis, gallbladder disease, clinically relevant gastric emptying disorders), cardiovascular, hepatic, psychiatric, neurologic, or severe allergic diseases. * Personal or first-degree family history of medullary thyroid carcinoma (MTC) or multiple endocrine neoplasia type 2 (MEN2), or suspected MTC. * Active or recent suicidal ideation in the past year, suicidal behavior within the past 5 years, or any psychiatric condition that increases risk in the investigator's judgment. * Clinically significant gastric emptying abnormality or chronically taking drugs that directly affect GI motility. * Acute gastrointestinal symptoms at screening or Day -1. * Known hypersensitivity to PF-08653945, amylin or calcitonin agonists, or any excipients. * Prior participation in any study involving PF-08653945 (formerly MET233) with at least one dose received.