Are Ozempic (semaglutide) or Mounjaro (tirzepatide) injections the primary treatment for type 1 diabetes?

Insulin Therapy Remains the Primary Treatment for Type 1 Diabetes, Not Ozempic or Mounjaro

Insulin therapy is the mainstay of treatment for type 1 diabetes, not Ozempic (semaglutide) or Mounjaro (tirzepatide). 1 These GLP-1 receptor agonists are not FDA-approved for type 1 diabetes management and should not be considered primary treatments.

Standard of Care for Type 1 Diabetes

The American Diabetes Association's 2024 Standards of Care clearly outlines the appropriate treatment approach:

• First-line therapy: Multiple daily insulin injections (MDI) or continuous subcutaneous insulin infusion (CSII/insulin pump) 1
• Insulin formulations: Insulin analogs are preferred over human insulins to minimize hypoglycemia 1
• Monitoring: Early use of continuous glucose monitoring is recommended 1
• Advanced options: Automated insulin delivery systems should be considered 1

Insulin Delivery Methods

1. Multiple Daily Injections (MDI):

   • 3-4 injections per day of basal and prandial insulin
   • Basal insulin (long-acting) provides background insulin
   • Prandial insulin (rapid-acting) covers meals and corrections

2. Continuous Subcutaneous Insulin Infusion (CSII):

   • Insulin pump delivering continuous basal insulin
   • Patient-activated boluses for meals and corrections
   • May be integrated with continuous glucose monitoring

Role of GLP-1 RAs in Type 1 Diabetes

While Ozempic (semaglutide) and Mounjaro (tirzepatide) have shown benefits in recent research, they are not primary treatments for type 1 diabetes:

• Off-label use only: These medications are not FDA-approved for type 1 diabetes 1
• Adjunctive therapy: May be considered as add-ons to insulin in specific cases
• Emerging evidence: Recent studies show potential benefits but are preliminary

Recent Research on GLP-1 RAs in Type 1 Diabetes

Recent studies have explored the use of these medications in type 1 diabetes:

• A 2025 retrospective study showed weight loss of 9.1% with semaglutide and 21.4% with tirzepatide in type 1 diabetes patients, along with modest HbA1c improvements (-0.54% and -0.68% respectively) 2

• A 2024 proof-of-concept study with tirzepatide in type 1 diabetes demonstrated HbA1c reduction of 0.59% at 8 months and weight reduction of 10.1% 3

• A 2025 randomized controlled trial of semaglutide in adults with type 1 diabetes and obesity showed improved time in range and weight reduction compared to placebo 4

Potential Benefits and Risks of GLP-1 RAs in Type 1 Diabetes

Potential Benefits:

• Weight reduction
• Modest improvement in glycemic control
• Reduced insulin requirements
• Possible cardiovascular benefits

Potential Risks:

• Increased risk of hypoglycemia when used with insulin
• Gastrointestinal side effects
• Risk of diabetic ketoacidosis
• Lack of long-term safety data in type 1 diabetes

Clinical Approach

For patients with type 1 diabetes:

1. Start with optimized insulin therapy using MDI or CSII
2. Ensure proper education on insulin dosing, carbohydrate counting, and sick day management
3. Consider continuous glucose monitoring to improve outcomes and reduce hypoglycemia
4. For patients with obesity or insulin resistance ("double diabetes"), discuss with endocrinology about the potential adjunctive use of GLP-1 RAs, understanding this would be off-label

Common Pitfalls to Avoid

• Substituting insulin: Never replace insulin with GLP-1 RAs in type 1 diabetes
• Inappropriate expectations: GLP-1 RAs cannot replace the need for exogenous insulin in type 1 diabetes
• Overlooking ketoacidosis risk: GLP-1 RAs may mask symptoms of insulin deficiency
• Ignoring insulin dose adjustments: When adding GLP-1 RAs, insulin doses typically need reduction to prevent hypoglycemia

In conclusion, while emerging research on GLP-1 RAs in type 1 diabetes shows promise for adjunctive therapy in specific populations, insulin therapy remains the cornerstone of treatment for all patients with type 1 diabetes.