The goal of this study is to learn if tirzepatide helps people manage their weight safely. It will include adults in Bangladesh who are overweight or obese, with or without type 2 diabetes. The main questions it aims to answer are: Does tirzepatide help people lose weight? What side effects do people experience while taking tirzepatide? All participants will: Receive tirzepatide as a weekly injection, starting at 2.5 mg and gradually increasing to 15 mg. Continue the treatment for 52 weeks (12 months). Visit the clinic for regular checkups and tests. Researchers will measure changes in body weight, BMI, waist size, blood sugar, blood pressure, and cholesterol levels. They will also track any side effects and assess the participants' overall health and quality of life during the study.

Obesity has emerged as a critical global public health issue, significantly linked to an increased risk of various comorbidities, including type 2 diabetes mellitus (T2DM), hypertension, dyslipidemia, and cardiovascular diseases. While lifestyle modifications, such as adhering to a low-calorie diet and enhancing physical activity, remain the cornerstone of obesity management, the recent development of anti-obesity medications such as GLP-1 agonists has transformed treatment options. This study aims to evaluate the efficacy and safety of tirzepatide, GLP-1 agonist, in weight management among overweight or obese adult individuals, both with and without T2DM in Bangladesh. This single treatment arm clinical trial will be conducted in a real-world setting, enrolling male and female adults aged 18 years or older, with a body mass index (BMI) of ≥30 kg/m² or ≥25-29.9 kg/m² if they have at least one weight-related comorbidity, such as, hypertension, or dyslipidemia. All the individuals recruited in the present study will receive subcutaneous injections of tirzepatide, initiated at a dose of 2.5 mg once weekly for the first four weeks, with incremental increases of 2.5 mg every four weeks, reaching the maintenance dose of 15 mg once weekly. The follow-up period will be 52 weeks (12 months) from the start of treatment. The primary efficacy endpoint will be the percentage change in body weight from baseline at week 52. Secondary endpoints will include the proportion of participants achieving weight reductions of ≥5%, ≥10%, ≥15%, and ≥20% after 52 weeks, as well as changes in body weight (kg), BMI (kg/m²), waist circumference (cm), HbA1c (%), fasting plasma glucose (FPG) (mg/dL), blood pressure (both systolic and diastolic), serum lipid levels (mg/dL), modifications in hypoglycemic and antihypertensive medications, and overall quality of life assessed through an obesity-specific QoL instrument. The study will also evaluate the incidence and severity of adverse events, alongside physical examination results, blood pressure measurements, and laboratory parameter changes from baseline. Adhering to Good Clinical Practice Guidelines, this study will follow ethical principles outlined in the Declaration of Helsinki.