From the Research
When transitioning from semaglutide (Wegovy) to tirzepatide (Mounjaro), the recommended approach is to discontinue semaglutide and start tirzepatide at the initial dose of 2.5 mg once weekly for 4 weeks. After this initial period, gradually increase the tirzepatide dose at 4-week intervals through the standard titration schedule: 2.5 mg to 5 mg, then to 7.5 mg, 10 mg, 12.5 mg, and finally to the maximum dose of 15 mg as tolerated. There is no need for a washout period between medications, as the transition can occur at the time of the next scheduled dose. For example, if a patient's last Wegovy injection was on Monday, they could start Mounjaro the following Monday. This approach minimizes the risk of loss of glycemic control while managing potential gastrointestinal side effects. The gradual titration is important because both medications work through similar mechanisms (GLP-1 receptor agonism), but tirzepatide also has GIP receptor agonist effects, which may cause different side effect profiles. Patients should be monitored for gastrointestinal side effects such as nausea, vomiting, and diarrhea during the transition, and dose adjustments may be needed based on individual tolerance. Adequate hydration and smaller, more frequent meals can help manage these side effects during the transition period, as supported by the findings of a study comparing tirzepatide and semaglutide 1. Additionally, a systematic review and network meta-analysis found that tirzepatide had a more pronounced effect on HbA1c and weight reduction compared to semaglutide 2. Another study also found that tirzepatide was associated with significantly greater mean percent weight reductions and reductions in HbA1c levels compared to semaglutide 3. It is essential to consider the cost-effectiveness of these medications, as a recent study found that tirzepatide and semaglutide were not cost-effective at current net prices, highlighting the need for efforts to reduce their costs 4. Overall, the transition from semaglutide to tirzepatide should be done under close monitoring, with a focus on minimizing side effects and maximizing the benefits of the new medication.