Wegovy (semaglutide) and Mounjaro (tirzepatide) have attracted growing attention as prescription medications used in medical weight management. They are not over-the-counter slimming products. Both require medical assessment, prescription, dose planning, and follow-up.
A doctor-led weight management plan should not focus only on the number on the scale. It usually considers BMI, waist circumference, blood pressure, blood glucose, cholesterol, fatty liver risk, sleep apnoea, past medical history, current medication, and lifestyle factors.
In Singapore, a practical weight management plan usually combines medical assessment, dietary and physical activity changes, medication selection where appropriate, and regular follow-up. Wegovy and Mounjaro may be part of this plan for selected patients, but the decision should be made after an individual medical review.
Key differences between Wegovy and Mounjaro
Wegovy contains semaglutide, a GLP-1 receptor agonist. It works through GLP-1-related pathways that help reduce appetite, slow stomach emptying, and support blood glucose and weight management.
Mounjaro contains tirzepatide. It acts on both GIP and GLP-1 receptor pathways, so it is often described as a GIP / GLP-1 receptor agonist. Because the mechanism is different, some patients may respond differently in terms of weight, appetite, and metabolic markers.
Both medications are typically given as once-weekly subcutaneous injections and should be used together with diet, physical activity, and follow-up. The best option depends on suitability, risks, tolerability, availability, and clinical goals.
| Comparison | Wegovy | Mounjaro |
|---|---|---|
| Active ingredient | Semaglutide | Tirzepatide |
| Main mechanism | GLP-1 receptor agonist | GIP / GLP-1 receptor agonist |
| Common dosing route | Once-weekly subcutaneous injection | Once-weekly subcutaneous injection |
| Role in weight management | Used with diet and physical activity | Used with diet and physical activity |
| Doctor assessment focus | BMI, metabolic risk, gastrointestinal tolerability, medical history | BMI, diabetes or metabolic risk, gastrointestinal tolerability, medical history |
Information shown may change as medication availability, approvals, and clinical guidance are updated. For general reference only.
Approval status in Singapore
Public information from Singapore's Health Sciences Authority (HSA) shows that Wegovy is registered locally for weight management. In February 2025, HSA also published a new indication approval for Wegovy for weight management in adolescents aged 12 years and above with obesity and body weight above 60 kg.
Mounjaro has also received updated approvals in Singapore. HSA's October 2025 new drug approvals state that Mounjaro is indicated for adults with insufficiently controlled type 2 diabetes, and also for weight management, including weight loss and weight maintenance, in adults with BMI ≥ 30 kg/m², or BMI ≥ 27 kg/m² to < 30 kg/m² with at least one weight-related comorbid condition.
This is why discussion of Wegovy and Mounjaro in Singapore should be based on local HSA-approved indications, medication availability, and a doctor's clinical assessment, rather than overseas marketing material alone.
What does a doctor usually assess?
Doctors usually do not prescribe based only on a target weight. Assessment may include:
- Current BMI, waist circumference, and weight trend
- Prediabetes, Type 2 diabetes, hypertension, high cholesterol, or fatty liver risk
- Past history involving the pancreas, gallbladder, thyroid, gastrointestinal system, or kidneys
- Current medication, allergy history, pregnancy plans, or breastfeeding
- Tolerability of gastrointestinal side effects such as nausea, vomiting, constipation, or diarrhoea
- Ability to follow dietary changes, physical activity, and regular review
Some patients may be best managed with lifestyle changes first. Others may benefit from prescription medication as part of a broader plan. Some may need blood pressure, glucose, sleep, or other metabolic issues addressed before or alongside weight management medication.
Tham Clinic now provides related services
Tham Clinic now provides doctor-led weight management consultations, including weight, BMI, and metabolic risk assessment, discussion of suitability for prescription options such as Wegovy and Mounjaro, and follow-up planning.
For enquiries about whether a medical weight management plan may be suitable, please contact the clinic through our Contact page. The doctor will assess personal health status, medical history, medication risks, and local medication availability before advising on next steps.
This article is for general health information only and does not replace a medical consultation, diagnosis, or personalised medical advice. Wegovy and Mounjaro require medical assessment and prescription.