Tirzepatide: Dosage & Administration
Part of the Tirzepatide Complete Guide
Research Peptides
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FDA-Approved Dosing Schedule
Tirzepatide (brand names Mounjaro for diabetes, Zepbound for weight management) uses a mandatory dose titration schedule. The 2.5 mg starting dose is a titration-only dose — it is not a therapeutic maintenance dose.
| Phase | Dose | Duration | Notes |
|---|---|---|---|
| Starting | 2.5 mg weekly | 4 weeks | Titration only — not a maintenance dose |
| First increase | 5 mg weekly | 4+ weeks | First potential maintenance dose |
| Second increase | 7.5 mg weekly | 4 weeks | Titration dose |
| Third increase | 10 mg weekly | 4+ weeks | Second potential maintenance dose |
| Fourth increase | 12.5 mg weekly | 4 weeks | Titration dose |
| Maximum | 15 mg weekly | Maintenance | Highest FDA-approved dose |
Key dosing principles:
- Dose titration is mandatory. Starting at higher doses causes severe GI side effects. Each increase is 2.5 mg every 4 weeks minimum
- Maintenance dose flexibility: Not everyone needs the maximum dose. Many patients achieve satisfactory results at 5 mg or 10 mg. Maintenance dose depends on individual response and tolerability
- For diabetes (Mounjaro): Target dose is 5–15 mg based on glycemic control
- For weight loss (Zepbound): Target dose is typically 10–15 mg for maximum weight loss
For comparison with semaglutide dosing, see tirzepatide vs semaglutide.
Administration & Injection Technique
Tirzepatide is administered as a once-weekly subcutaneous injection using pre-filled auto-injector pens:
- Injection sites: Abdomen, thigh, or upper arm — rotate sites weekly to prevent lipodystrophy
- Timing: Any day of the week, any time of day, with or without meals. Choose a consistent day each week
- Day change: The injection day can be changed as long as the last dose was at least 3 days (72 hours) prior
- Pen use: Each pen contains one dose. The pen is single-use and should be discarded after injection. The needle is hidden in auto-injector designs
Missed Dose Protocol
- If within 4 days (96 hours) of the scheduled dose: administer as soon as possible
- If more than 4 days late: skip the missed dose and resume on the next scheduled day
- Resume the regular once-weekly schedule from the new day
Storage & Handling
| Form | Storage | Duration |
|---|---|---|
| Unopened pens | Refrigerate 2–8°C (36–46°F) | Until expiration date |
| Unopened at room temp | Up to 30°C (86°F) | Up to 21 days, then discard |
| Do not freeze | Discard if frozen | — |
Protect from light. Do not use if solution appears cloudy, discolored, or contains particles. For research-grade lyophilized tirzepatide, use the peptide calculator for reconstitution volumes and the storage guide for handling protocols.