Zepbound Volume for One-Month Supply
For a one-month supply of Zepbound (tirzepatide) with weekly dosing, you need 2 mL total (0.5 mL per injection × 4 weekly doses).
Dosing Details
Zepbound is administered as a once-weekly subcutaneous injection 1, 2, 3. Each single-use pen delivers 0.5 mL per injection, regardless of the dose strength (2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, or 15 mg) 1, 3.
Monthly Volume Calculation:
- 0.5 mL per week × 4 weeks = 2 mL per month
- This equals 4 single-use pens per month (one pen per week)
Dose Escalation Schedule
Tirzepatide follows a structured dose escalation:
- Weeks 1-4: 2.5 mg (0.5 mL) weekly
- Weeks 5-8: 5 mg (0.5 mL) weekly
- Weeks 9-12: 7.5 mg (0.5 mL) weekly
- Weeks 13-16: 10 mg (0.5 mL) weekly
- Weeks 17-20: 12.5 mg (0.5 mL) weekly
- Week 21+: 15 mg (0.5 mL) weekly (maximum tolerated dose)
The maintenance dose is typically 10 mg or 15 mg weekly 4, 5, 6, 7, 8.
Key Clinical Points
Volume remains constant: The 0.5 mL injection volume stays the same across all dose strengths—only the concentration changes 1, 3. This is critical for patient education and prescription accuracy.
Prescription specifications: When prescribing for one month, specify "4 single-use pens" of the appropriate dose strength, which provides the 2 mL total volume needed for weekly administration.
The dose escalation period typically spans 20 weeks before reaching the maximum tolerated dose, so monthly prescriptions will involve different dose strengths during titration 8, 9.