Can type 1 diabetic patients use Zepbound (tirzepatide) for weight loss?

Use of Tirzepatide (Zepbound) for Weight Loss in Type 1 Diabetic Patients

Tirzepatide (Zepbound) is not FDA-approved for use in type 1 diabetes patients for weight loss, but recent research shows promising results with significant weight reduction and improved glycemic control when used off-label in this population.

Current Status and Evidence

• Tirzepatide is FDA-approved for type 2 diabetes management and obesity treatment in non-diabetic individuals, but it is not currently approved for use in type 1 diabetes 1.

• The American Diabetes Association guidelines mention that glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and other agents used for type 2 diabetes are being studied in patients with type 1 diabetes, but they remain investigational in this population 1.

• Recent retrospective studies have shown promising results with tirzepatide in type 1 diabetes:

  • A 2024 study demonstrated an average 18.5% weight loss (approximately 46 pounds) and improved glucose control in overweight/obese type 1 diabetes patients after 1 year of tirzepatide use 2.
  • Another 2024 study showed 10.1% weight reduction and significant HbA1c improvement (-0.59%) over 8 months 3.
  • A 2025 study reported 23.4% weight loss and sustained glycemic improvement (-0.50% HbA1c) over 21 months with tirzepatide 4.

Benefits and Risks

Potential Benefits:

• Significant weight reduction (10-23% of body weight) 2, 5, 3, 4
• Improved glycemic control with HbA1c reductions of 0.5-0.7% 2, 5, 3
• Reduced insulin requirements 2, 6
• Improved time in range for continuous glucose monitoring users 2, 3
• Potential cardiovascular and renal benefits, including improved lipid profiles, blood pressure, and preserved kidney function 4

Potential Risks:

• Increased risk of hypoglycemia if insulin doses are not appropriately adjusted 1
• Gastrointestinal side effects (nausea, vomiting, diarrhea) 1
• Potential risk of diabetic ketoacidosis (DKA), though this has been more commonly reported with SGLT2 inhibitors rather than GLP-1 RAs 1
• Limited long-term safety data in type 1 diabetes population 1

Clinical Approach

If considering tirzepatide for a type 1 diabetes patient with obesity:

1. Discuss off-label status: Clearly inform the patient that this is an off-label use not currently approved by the FDA 1.

2. Patient selection: Consider for patients with:

   • BMI ≥30 kg/m² or ≥27 kg/m² with weight-related comorbidities 1
   • Suboptimal glycemic control despite optimized insulin therapy 2, 5
   • No history of recurrent severe hypoglycemia or DKA 1

3. Dosing and monitoring:

   • Start with low dose (2.5 mg weekly) and gradually titrate as tolerated 6
   • Monitor blood glucose closely and adjust insulin doses accordingly 2, 6
   • Regular follow-up to assess weight, glycemic control, and potential adverse effects 2, 3

4. Safety precautions:

   • Educate on signs/symptoms of hypoglycemia and DKA 1
   • Ensure patient has glucagon available for emergency hypoglycemia management 1
   • Consider continuous glucose monitoring to detect glycemic patterns 2, 3

Conclusion

While emerging research suggests tirzepatide may be beneficial for weight management in type 1 diabetes patients, larger prospective randomized controlled trials are needed to establish its safety and efficacy in this population 2, 5, 3, 4. The decision to use tirzepatide off-label should be made after careful consideration of potential benefits and risks, with close monitoring and appropriate insulin dose adjustments.