How to Use Tirzepatide (Mounjaro/Zepbound): Dosing Titration Guide
Complete tirzepatide dosing guide — starting dose (2.5mg/week), titration schedule, injection technique, and comparison with semaglutide.
Overview
Tirzepatide (Mounjaro/Zepbound) is a dual GIP/GLP-1 receptor agonist FDA-approved for type 2 diabetes and weight management. It produces greater weight loss than semaglutide in head-to-head trials. This guide covers the titration protocol and practical use.
What You Need
- Tirzepatide pen (Mounjaro/Zepbound) or compounded tirzepatide vial
- Pen needles or insulin syringes
- Alcohol swabs
- Sharps container
Step-by-Step Instructions
Start at 2.5mg per week
The starting dose is 2.5mg once weekly for 4 weeks. Like semaglutide, this is a sub-therapeutic dose for GI adaptation.
Escalate to 5mg at week 5
If 2.5mg is well tolerated, increase to 5mg at week 5. This is the first therapeutic dose where meaningful appetite suppression begins.
Continue titration
Standard titration: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg, each for 4 weeks. The maximum dose is 15mg/week. Advance only if the current dose is well tolerated.
Inject subcutaneously
Inject into the abdomen, outer thigh, or upper arm. Rotate sites weekly. The Mounjaro/Zepbound auto-injector pen makes injection straightforward.
Manage side effects
GI side effects (nausea, diarrhea, constipation) are similar to semaglutide but may be more pronounced at higher doses. Strategies: smaller meals, avoid trigger foods, consider anti-nausea medication, inject at bedtime.
Common Mistakes to Avoid
Comparing tirzepatide doses to semaglutide doses directly
Fix: Tirzepatide and semaglutide doses are not equivalent. 5mg tirzepatide is not the same as 0.5mg semaglutide — they are different molecules with different potency scales.
Stopping at 5mg if results are insufficient
Fix: Tirzepatide's weight loss effect increases with dose. If 5mg is well tolerated but results are modest, continue titrating to 7.5–10mg.
Neglecting protein intake
Fix: GLP-1/GIP agonists suppress appetite broadly. Ensure adequate protein (1.2–1.6g/kg/day) to preserve lean muscle mass during weight loss.
Frequently Asked Questions
Is tirzepatide better than semaglutide for weight loss?
Head-to-head trials (SURMOUNT-5) show tirzepatide produces greater weight loss than semaglutide (20–22% vs. 15–17% of body weight). Tirzepatide's dual GIP/GLP-1 mechanism appears to provide additive benefits.
What is the difference between Mounjaro and Zepbound?
Both contain tirzepatide. Mounjaro is FDA-approved for type 2 diabetes. Zepbound is FDA-approved for chronic weight management. The drug is identical; the indication and marketing differ.
How long does tirzepatide take to work?
Meaningful appetite suppression typically begins at 5mg (weeks 5–8). Significant weight loss (5%+ of body weight) is usually seen by weeks 12–16.
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