Tirzepatide (Mounjaro) Dosing Regimen for Weight Loss
The recommended dosing regimen for tirzepatide (Mounjaro) for weight loss is to start with a low dose and gradually increase to a maintenance dose of 10 mg or 15 mg once weekly via subcutaneous injection, as these doses have demonstrated superior weight loss outcomes. 1
Initial Dosing and Titration
- Start with a low dose and gradually increase to minimize gastrointestinal side effects, which are the most common adverse events 1
- Administer as a subcutaneous injection once weekly 1
- Follow a gradual dose escalation protocol to reach the maintenance dose 1
Maintenance Dosing
- The maintenance doses for weight loss are 10 mg or 15 mg once weekly 1
- These doses have demonstrated superior weight loss outcomes in clinical trials 1, 2
- In the SURMOUNT-1 trial, tirzepatide at 15 mg weekly resulted in a mean weight reduction of 20.9% at 72 weeks, compared to 19.5% with 10 mg and 15.0% with 5 mg 2
Monitoring and Efficacy Assessment
- Assess efficacy and safety at least monthly for the first 3 months and at least quarterly thereafter 3, 1
- Early responders typically have improved long-term outcomes 3
- If insufficient weight loss is achieved, consider discontinuing the medication and exploring other treatment options 3, 1
Side Effects Management
- Most common adverse events are gastrointestinal (nausea, diarrhea, decreased appetite, vomiting), primarily occurring during dose escalation 1, 4
- These side effects are typically mild to moderate in severity 2, 4
- The gradual dose titration approach helps minimize these gastrointestinal side effects 1
Important Contraindications and Precautions
- Contraindicated in women who are or may become pregnant 3, 1
- Women of reproductive potential must use reliable contraception methods 3, 1
- Monitor for potential pancreatitis and discontinue if suspected 3, 1
- Use caution in patients with kidney disease when initiating or increasing dose due to potential risk of acute kidney injury 3, 1
- Be aware of the black box warning regarding risk of thyroid C-cell tumors in rodents (human relevance not determined) 3, 1
Long-Term Efficacy
- In a 3-year study (SURMOUNT-1), participants maintained significant weight loss with tirzepatide: -12.3% with 5 mg, -18.7% with 10 mg, and -19.7% with 15 mg, compared to -1.3% with placebo 5
- Tirzepatide not only reduces weight but also improves health-related quality of life, with greater improvements observed in those achieving higher weight reduction thresholds 6
Clinical Benefits Beyond Weight Loss
- Tirzepatide significantly reduces the risk of progression to type 2 diabetes in people with obesity and prediabetes 5
- Treatment results in improvements in cardiometabolic measures 2
- As a dual GIP and GLP-1 receptor agonist, tirzepatide can significantly reduce glycemic levels and improve insulin sensitivity 7, 4