What is the recommended treatment option between Mounjaro (tirzepatide) and Zepbound for type 2 diabetes?

Mounjaro and Zepbound Are the Same Medication

Mounjaro and Zepbound are both brand names for tirzepatide—they are the exact same drug, just marketed under different names for different indications. Mounjaro is FDA-approved for type 2 diabetes management, while Zepbound is approved for chronic weight management in adults with obesity or overweight with weight-related comorbidities 1, 2.

Understanding the Distinction

• Mounjaro (tirzepatide) is indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus 1, 3
• Zepbound (tirzepatide) is the same molecule approved specifically for chronic weight management 4
• Both formulations contain identical active ingredient—tirzepatide, a dual GIP/GLP-1 receptor agonist 2, 5

For Type 2 Diabetes: Use Mounjaro

If treating type 2 diabetes, prescribe Mounjaro, as it is the FDA-approved formulation for glycemic control and is supported by the most robust clinical trial evidence in this population. 1, 3

Evidence Supporting Tirzepatide for Type 2 Diabetes

• The SURPASS clinical trial program (SURPASS 1-5) demonstrated unprecedented glycemic control with HbA1c reductions of 1.87% to 3.02% across various patient populations 3, 4
• Tirzepatide achieved superior glycemic control compared to semaglutide 1 mg, dulaglutide, and basal insulin 1, 2
• Between 23.0% to 62.4% of patients achieved normoglycemia (HbA1c <5.7%) on tirzepatide 2
• Weight loss ranged from 5.4 to 12.9 kg, with 20.7% to 68.4% of patients losing more than 10% of baseline body weight 2, 4

Guideline-Based Positioning

The 2025 ADA Standards of Care recommend GLP-1 receptor agonists (and by extension, dual GIP/GLP-1 agonists like tirzepatide) for patients with type 2 diabetes and established cardiovascular disease or at very high cardiovascular risk. 6

• Tirzepatide should be considered when HbA1c is ≥1.5% above individualized glycemic goal, as dual combination therapy or a more potent agent is typically required 6
• The American Heart Association suggests that Mounjaro may be particularly beneficial for patients with established cardiovascular disease or high cardiovascular risk 7
• Tirzepatide can be used in combination with metformin for enhanced glycemic control, as recommended by the European Association for the Study of Diabetes 7

Practical Prescribing Considerations

• Starting dose: 2.5 mg subcutaneously once weekly for 4 weeks (this is a dose escalation period, not a therapeutic dose) 1
• Maintenance doses: 5 mg, 10 mg, or 15 mg once weekly based on glycemic response and tolerability 1, 3
• Renal considerations: No dosage adjustment needed for patients with eGFR ≥20 mL/min/1.73 m² per National Kidney Foundation guidance 7
• Monitoring: Track HbA1c regularly to assess glycemic response, as recommended by the American Association of Clinical Endocrinologists 7

Safety Profile

• Adverse events are similar to GLP-1 receptor agonists, predominantly gastrointestinal (nausea, diarrhea, decreased appetite, vomiting), mostly mild to moderate 1, 5
• Low risk of clinically significant or severe hypoglycemia when not combined with insulin or sulfonylureas 1, 3
• No increased risk of major adverse cardiovascular events; meta-analysis showed hazard ratio <1.0 for MACE-4 versus pooled comparators 2
• Critical perioperative consideration: The American Society of Anesthesiologists and American College of Surgeons recommend holding tirzepatide the week before elective procedures due to delayed gastric emptying concerns 7

Common Pitfalls to Avoid

• Do not confuse brand names—prescribe "Mounjaro" specifically for diabetes indication to ensure proper insurance coverage and patient understanding 1
• Do not start at therapeutic doses—the 2.5 mg starting dose for 4 weeks is essential for tolerability 1
• Avoid combining with sulfonylureas until metabolically stable, as this increases hypoglycemia risk, per European Association for the Study of Diabetes guidance 8
• Do not rely on sliding scale insulin alone without basal insulin coverage when transitioning patients, as this approach is strongly discouraged by the American Diabetes Association 8