With growing global availability of tirzepatida (Mounjaro®), many patients on stable semaglutide (Ozempic®, Wegovy®) consult their clinicians about transitioning to dual GIP and GLP-1 receptor coagonism.
The Half-Life Rule: When to Administer the First Dose
Both medications carry a circulating plasma half-life of roughly 5 to 7 days. Clinical guidelines instruct patients to inject their first Mounjaro dose on the exact calendar day their next Ozempic dose was scheduled, preventing harmful drug level overlaps.
Equivalence & Starting Titration Practices
- Ozempic 0.25 mg or 0.5 mg: Start on Mounjaro 2.5 mg weekly for 4 weeks to acclimatize GIP sensitivity.
- Ozempic 1.0 mg: Clinicians select 2.5 mg or, with proven gastric tolerance, 5.0 mg weekly.
- Ozempic 2.0 mg / Wegovy 2.4 mg: Best practice initiates at 5.0 mg for 4 weeks before progressing to 7.5 mg or higher.
