This is a prospective cohort study of 12 overweight (with one or more weight-related condition) or obese adults with well controlled HIV-1 on antiretroviral therapy (ART). An initial dose of tirzepatide (TZP) 2.5 mg subcutaneous (SQ) once weekly will be given, escalated by 2.5 mg at 4-week intervals to a final dose of 7.5mg. The investigators will collect the following information via review of the medical record: age, race/ethnicity, sex, medical conditions, medications, most recent standard of care HIV labs (including T-cell panel and HIV-1 viral load). The primary outcome will be the change in baseline body weight at 12 weeks. Secondary outcomes will be changes in body composition, liver fat content and liver stiffness, inflammatory markers, cardiometabolic markers (lipids and HbA1c), and monocytes at 12 weeks. There will be a 4-week safety follow up off TZP.