Transitioning from Wegovy 2.4mg to Mounjaro 5mg
When transitioning from Wegovy (semaglutide) 2.4mg to Mounjaro (tirzepatide) 5mg, patients should discontinue semaglutide completely and start tirzepatide at 2.5mg weekly for 4 weeks before increasing to 5mg.
Rationale for Transition
Tirzepatide offers superior weight loss outcomes compared to semaglutide:
- Tirzepatide has demonstrated greater weight reduction than semaglutide in clinical studies (20.2% vs 13.7% weight loss) 1
- Tirzepatide provides better value for money for weight reduction ($985 vs $1845 per 1% body weight reduction) 2
- Tirzepatide acts as a dual GIP/GLP-1 receptor agonist, while semaglutide is only a GLP-1 receptor agonist, providing a different mechanism of action 3
Transition Protocol
Step 1: Discontinue Semaglutide
- Stop Wegovy 2.4mg completely
- No tapering of semaglutide is required before starting tirzepatide
- Allow at least 7 days between the last dose of semaglutide and the first dose of tirzepatide
Step 2: Initiate Tirzepatide
- Start with tirzepatide 2.5mg weekly for 4 weeks
- This initial lower dose helps minimize gastrointestinal side effects
- After 4 weeks, increase to the target dose of 5mg weekly
Step 3: Monitoring and Dose Adjustments
- Monitor for GI side effects (nausea, vomiting, diarrhea)
- If significant side effects occur, consider extending time at 2.5mg before increasing to 5mg
- Assess weight loss response and glycemic control (if applicable) at 4-week intervals
Managing Side Effects
Both medications have similar side effect profiles, primarily gastrointestinal in nature:
- For nausea/vomiting: Consider ondansetron 4-8mg as needed or metoclopramide 5-10mg before meals 4
- For diarrhea: Loperamide 2mg after each loose stool (maximum 8mg/day) 4
- Dietary modifications: Smaller, more frequent meals, avoiding high-fat foods, adequate hydration (2-3 liters daily) 4
Important Considerations
- Medication overlap: Do not use tirzepatide concurrently with semaglutide or other GLP-1 RAs 5
- Hypoglycemia risk: If the patient is on insulin or insulin secretagogues, doses may need adjustment to prevent hypoglycemia 4
- Medication absorption: Both medications may delay gastric emptying, potentially affecting absorption of other oral medications 5, 4
- Follow-up timing: Schedule follow-up within 4 weeks of transition to assess tolerability and efficacy 4
Potential Challenges
- Patients may experience a temporary increase in GI side effects during the transition period
- Some patients may notice a brief plateau in weight loss during the transition
- Insurance coverage and prior authorization requirements may differ between the two medications
By following this structured transition protocol, patients can successfully switch from Wegovy to Mounjaro while minimizing side effects and maintaining therapeutic benefits.