Tirzepatide dosage
You are trying to work out how much to draw or when to step up.
Reference and calculator, not medical advice. Dosing figures below are transcribed from FDA-approved prescribing information and link back to it. Last reviewed August 2026.
Tirzepatide is dosed once weekly and escalates through six steps, from 2.5 mg to a labelled maximum of 15 mg. The 2.5 mg step is explicitly described in the prescribing information as a starting dose rather than a therapeutic one — it exists to let the body adjust, which is why the schedule holds it for four weeks before the first increase.
Zepbound titration schedule
Tirzepatide · once weekly · subcutaneous injection · as published in the prescribing information
| Step | Dose | Notes |
|---|---|---|
| Weeks 1–4 | 2.5 mg | Starting dose — not intended for weight loss effect |
| Weeks 5–8 | 5 mg | — |
| Weeks 9–12 | 7.5 mg | — |
| Weeks 13–16 | 10 mg | — |
| Weeks 17–20 | 12.5 mg | — |
| Week 21+ | 15 mg | Maximum dose |
This is the labelled default. Holding at a step longer than shown is common practice and is a decision for your prescriber. Transcribed from the Zepbound prescribing information (label revised 6 May 2026); checked against that label on 7 August 2026.
Zepbound and Mounjaro are the same molecule on the same schedule; they differ in labelled indication (weight management versus type 2 diabetes), not in how they are dosed. If you have seen conflicting dose charts, this is usually why.
Side-by-side
Structural facts from each product’s prescribing information.
| Product | Active ingredient | Indication | Frequency | Start | Max labelled | Steps to max |
|---|---|---|---|---|---|---|
| Zepbound Eli Lilly | Tirzepatide | Weight management | Weekly | 2.5 mg | 15 mg | 6 |
| Mounjaro Eli Lilly | Tirzepatide | Type 2 diabetes | Weekly | 2.5 mg | 15 mg | 6 |
If you are using a pen, the dose is fixed and there is nothing to calculate. If you are drawing from a vial, the number on the syringe depends on the vial's concentration — the same milligram dose is a completely different mark at 5 mg/mL versus 20 mg/mL. That conversion is below.
Zepbound dose → units reference
U-100 syringe units for each labelled dose, at the concentrations commonly supplied.
| Dose | 5 mg/mL | 10 mg/mL | 20 mg/mL |
|---|---|---|---|
| 2.5 mg | 50.0 u | 25.0 u | 12.5 u |
| 5 mg | 100.0 u | 50.0 u | 25.0 u |
| 7.5 mg | 150.0 u | 75.0 u | 37.5 u |
| 10 mg | 200.0 u | 100.0 u | 50.0 u |
| 12.5 mg | 250.0 u | 125.0 u | 62.5 u |
| 15 mg | 300.0 u | 150.0 u | 75.0 u |
Only use the column matching the concentration printed on your vial.
mg → syringe units converter
U-100 syringe. Formula: (dose ÷ concentration) × 100.
Check the concentration printed on the vial you are actually holding. The same dose in milligrams is a completely different mark on the syringe at a different concentration. If the number here does not match what your prescriber told you, trust your prescriber.
Common questions
- Do I have to reach 15 mg?
- No. The schedule describes the maximum labelled dose, not a destination. Many people maintain below it indefinitely, and the prescribing information itself frames escalation as continuing only if additional effect is needed and tolerated.
- What happens if I hold at a step longer than four weeks?
- Holding is routine practice and is often how prescribers manage side effects. The four-week interval in the label is a minimum before increasing, not a requirement to increase.
- Can I skip a step?
- The schedule is stepped deliberately — escalation speed is what drives gastrointestinal effects. Any deviation is a decision for your prescriber, not something to work out from a chart.
- How does tirzepatide dosing compare to semaglutide?
- They run on completely different milligram scales. Tirzepatide goes 2.5 → 15 mg; semaglutide for weight management goes 0.25 → 2.4 mg. A "5 mg dose" means nothing without saying which drug — comparing the numbers directly is meaningless.
Common questions
- What is the starting dose of Zepbound?
- The prescribing information lists 2.5 mg once weekly as the starting dose, held for the first four weeks before any increase.
- What is the maximum labelled dose of Zepbound?
- 15 mg once weekly, reached through the stepped schedule shown above.
- How many units is 5 mg at 20 mg/mL?
- 25.0 units on a U-100 syringe. The arithmetic is (dose ÷ concentration) × 100, and it only holds if the concentration on your vial matches.
Sources and last review
Every dosing figure on this page is transcribed from an FDA-approved label and links back to it. Conversions are arithmetic you can repeat by hand. Nothing here is reviewed by a clinician, and this site does not employ one — which is exactly why what I do publish stays traceable to its source.
- Zepbound (Tirzepatide) prescribing information — Eli Lilly, label revised 6 May 2026, checked 7 August 2026
- Mounjaro (Tirzepatide) prescribing information — Eli Lilly, label revised 6 May 2026, checked 7 August 2026
Transcribed from the labels above and checked by me — Gavin, who builds this site, takes a GLP-1, and is not a clinician. Last reviewed August 2026. Found an error? [email protected] — I treat corrections as bugs. How this site is built and funded.
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