FDA-Approved Indications for Mounjaro (Tirzepatide)
Mounjaro (tirzepatide) is FDA-approved as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. 1, 2, 3
Primary Indication
- Type 2 Diabetes Mellitus: Tirzepatide is approved specifically for adults with type 2 diabetes as an add-on therapy to lifestyle modifications (diet and exercise) to improve blood glucose control 1, 2, 3
Key Clinical Context
What Tirzepatide Is NOT Currently Approved For:
- Type 1 diabetes: Despite some observational data showing potential benefit, tirzepatide does not have FDA approval for type 1 diabetes 4
- Weight management as a standalone indication: While tirzepatide causes substantial weight loss (5.4-11.7 kg in clinical trials), it is currently approved only for type 2 diabetes, though weight management indications are under investigation 5
- Cardiovascular risk reduction: Unlike some other diabetes medications, tirzepatide does not yet have a specific cardiovascular outcomes indication, though cardiovascular safety has been demonstrated 5
Mechanism and Clinical Profile:
- Tirzepatide is a first-in-class dual GIP/GLP-1 receptor agonist that works by increasing insulin secretion, reducing glucagon release in a glucose-dependent manner, promoting satiety, and delaying gastric emptying 3
- It is administered as a once-weekly subcutaneous injection at doses of 5 mg, 10 mg, or 15 mg 1, 5
Clinical Efficacy in Approved Indication:
- In the SURPASS clinical trial program, tirzepatide demonstrated unprecedented HbA1c reductions of 1.87% to 2.59% 1
- Weight loss ranged from 6.2 to 12.9 kg across trials 1
- 23.0% to 62.4% of patients achieved normoglycemia (HbA1c <5.7%) 5
- Tirzepatide showed superior efficacy compared to semaglutide 1 mg and titrated basal insulin 1, 5
Important Prescribing Considerations:
- The medication can be used as monotherapy or in combination with other antihyperglycemic agents 3
- Common adverse events are gastrointestinal (nausea, vomiting, diarrhea, constipation), similar to GLP-1 receptor agonists 5
- Low risk of hypoglycemia when used without insulin or insulin secretagogues 1
- No dose adjustment typically required for mild to moderate renal impairment 6
Guidelines Support Use in Type 2 Diabetes:
- The American Diabetes Association recommends prioritizing GLP-1 receptor agonists or dual GIP/GLP-1 receptor agonists with greater weight loss efficacy (specifically mentioning semaglutide or tirzepatide) for patients with type 2 diabetes and overweight or obesity, given their glycemic and cardiometabolic benefits 7
- When choosing glucose-lowering medications for people with type 2 diabetes and overweight or obesity, guidelines recommend prioritizing medications with beneficial effects on weight 7