Mounjaro (Tirzepatide) Dosage for Type 2 Diabetes
Start Mounjaro at 2.5 mg subcutaneously once weekly for 4 weeks, then increase to 5 mg once weekly, with further escalation to 10 mg and ultimately 15 mg once weekly at 4-week intervals based on glycemic response and tolerability. 1
Initial Dosing and Titration Protocol
The 2.5 mg starting dose is not therapeutic—it serves only to minimize gastrointestinal side effects during the first month. 1 After this initial 4-week period, increase to the first therapeutic dose of 5 mg once weekly. 1
Standard Titration Schedule:
- Weeks 1-4: 2.5 mg once weekly (initiation dose only) 1
- Weeks 5-8: 5 mg once weekly (first therapeutic dose) 1
- Weeks 9-12: 10 mg once weekly (if additional glycemic control needed) 1
- Week 13+: 15 mg once weekly (maximum dose for optimal glycemic control) 1
Each dose escalation requires a minimum of 4 weeks at the current dose before advancing. 1 This gradual titration minimizes the gastrointestinal adverse effects (nausea, vomiting, diarrhea) that occur in 12-22% of patients. 1
Efficacy Expectations by Dose
Tirzepatide demonstrates dose-dependent efficacy for both glycemic control and weight loss:
- 5 mg weekly: HbA1c reduction of 1.87%, with 23.0% of patients achieving HbA1c <5.7% 2
- 10 mg weekly: HbA1c reduction of 2.01-2.24%, with weight loss of 7.5 kg 3, 4
- 15 mg weekly: HbA1c reduction of 2.30-2.58%, with weight loss of 8.8-11.7 kg and 62.4% of patients achieving HbA1c <5.7% 3, 2, 4
Tirzepatide at 15 mg weekly achieves superior glycemic control compared to semaglutide 1 mg weekly, with an additional 0.45 percentage point reduction in HbA1c (95% CI -0.57 to -0.32, P<0.001). 4
Renal Dosing Considerations
No dosage adjustments are required regardless of renal function, including patients with severe renal impairment or end-stage renal disease. 1 This represents a significant advantage over many other antidiabetic medications that require dose reduction or are contraindicated in advanced chronic kidney disease. 1
Concomitant Medication Adjustments
When Adding Tirzepatide to Insulin:
Reduce basal insulin by 20% immediately when initiating tirzepatide to prevent hypoglycemia. 1 For patients with HbA1c <8%, consider a more aggressive reduction of 4 units or discontinuing prandial insulin entirely. 1
When Adding Tirzepatide to Sulfonylureas:
Reduce sulfonylurea doses by 50% or discontinue entirely when starting tirzepatide, as the combination significantly increases hypoglycemia risk. 1
Safety Monitoring During Titration
Monitor patients every 4 weeks during dose escalation for:
- Gastrointestinal tolerance (nausea, vomiting, diarrhea occur in 13-22% of patients) 4
- Weight loss progress (expect 5.4-11.7 kg reduction depending on final dose) 3, 2
- Signs of hypoglycemia if combined with insulin or sulfonylureas 1
- Persistent severe abdominal pain (potential pancreatitis) 1
Absolute Contraindications
Do not prescribe tirzepatide to patients with:
- Personal or family history of medullary thyroid cancer 1
- Multiple endocrine neoplasia type 2 (MEN2) 1
- History of serious hypersensitivity reaction to tirzepatide 1
Common Pitfalls to Avoid
Do not skip the 2.5 mg initiation phase—starting at 5 mg significantly increases gastrointestinal adverse effects and treatment discontinuation. 1 The gradual titration is essential for tolerability, even though 2.5 mg provides minimal glycemic benefit. 1
Do not advance doses faster than every 4 weeks—premature escalation increases nausea and vomiting rates, leading to treatment discontinuation in up to 18% of patients. 3
Do not combine tirzepatide with other GLP-1 receptor agonists or DPP-4 inhibitors—this provides no additional benefit and increases adverse effects. 1