Tirzepatide (Mounjaro, Zepbound) is a dual GIP and GLP-1 receptor agonist. For the prescriber it's a different molecule with its own dose schedule; for the dietitian, the priorities are the same as for semaglutide: manage symptoms through titration, protect protein and lean mass, and safeguard adequacy on a shrinking food volume. What changes is the schedule, so it is worth knowing.
- Tirzepatide titrates in 2.5 mg steps, no sooner than every 4 weeks, up to 15 mg.
- GI symptoms cluster after each step, just like semaglutide.
- The dietetic priorities are identical: tolerability, protein/lean mass, adequacy.
- Missed-dose and switching decisions belong to the label and prescriber, not the diet plan.
The titration schedule
Tirzepatide is escalated slowly for tolerability, in fixed 2.5 mg increments, with at least four weeks at each step before any increase.
| Step | Weekly dose | Note |
|---|---|---|
| Weeks 1–4 | 2.5 mg | Initiation, not a therapeutic dose |
| Weeks 5–8 | 5 mg | First therapeutic dose |
| Then, ≥4 weeks apart | 7.5 mg → 10 mg | Increase as needed / tolerated |
| Then, ≥4 weeks apart | 12.5 mg → 15 mg | 15 mg is the maximum |
This is the published label schedule and can change; brand availability and indications differ by country (including South Africa). Confirm against the current SmPC / package insert for your patient's product before giving any dose-linked advice. Educational reference only, not prescribing guidance.
Missed doses and switching
Missed-dose handling is defined by the label and depends on how much time has passed; switching between tirzepatide and semaglutide (in either direction) follows specific protocols. These are prescriber and pharmacist decisions. The dietitian's relevance is simply awareness, a missed dose or a switch can shift appetite and symptoms, which affects your counselling and monitoring.
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Nutrition counselling across the curve
The mapping is the same as for semaglutide: early doses focus on tolerability and habit architecture; mid doses bring protein and lean-mass protection to the front; maintenance is about adequacy and durability on a much smaller food volume. If you counsel patients on both drugs, you don't need two mental models, one framework, two schedules.
Because the dietetic priorities carry across both agents, the deepest value is in mastering the framework once. See our companion guides on semaglutide titration, protecting lean mass, and managing GI side effects.
The scope edge
As with all GLP-1 therapies: dietitians educate, monitor and optimise nutrition; they do not initiate, titrate, hold or stop the drug. Tolerability problems and dosing questions go to the prescriber, with a clear note on intake, hydration and symptoms.