Tirzepatide has six weekly doses: 2.5, 5, 7.5, 10, 12.5 and 15 mg. You start at 2.5 mg for four weeks, then step up by 2.5 mg at a time, with at least four weeks on each step. On a U-100 insulin syringe with a 10 mg/mL compounded vial, those doses are 25, 50, 75, 100, 125 and 150 units. If you are new to the drug, start with our tirzepatide guide, then use the charts below.
Key takeaways
- The Zepbound and Mounjaro labels start everyone at 2.5 mg once weekly for 4 weeks, then raise the dose in 2.5 mg steps after at least 4 weeks on the current dose. The maximum is 15 mg once weekly.
- Maintenance doses on the Zepbound label are 5, 10 or 15 mg. The 2.5 mg dose is a starting dose, not a maintenance dose.
- Syringe units depend on the concentration printed on your vial. At 10 mg/mL, units equal mg times 10. At 5 mg/mL the units double. At 20 mg/mL they halve.
- A missed dose can be taken within 4 days (96 hours). After that, skip it. Never take two doses within 3 days of each other.
- In SURMOUNT-1, average weight loss at 72 weeks was 15.0% at 5 mg, 19.5% at 10 mg and 20.9% at 15 mg, versus 3.1% on placebo.
Tirzepatide dosage chart: the labeled schedule
This is the dose-escalation schedule from the Zepbound and Mounjaro prescribing information. Both drugs are tirzepatide and both use the same six strengths. Your prescriber can hold you at any step longer than four weeks if side effects need time to settle. The schedule is a ceiling on how fast you can go up, not a target you must hit.
| Weekly dose | Earliest weeks on this dose | Role per the label |
|---|---|---|
| 2.5 mg | Weeks 1 to 4 | Starting dose (not a maintenance dose) |
| 5 mg | Weeks 5 to 8 | First maintenance dose |
| 7.5 mg | Weeks 9 to 12 | Step-up dose |
| 10 mg | Weeks 13 to 16 | Maintenance dose |
| 12.5 mg | Weeks 17 to 20 | Step-up dose |
| 15 mg | Week 21 onward | Maximum maintenance dose |
Source: Zepbound and Mounjaro prescribing information (DailyMed), Dosage and Administration.
The "earliest weeks" column assumes you move up at every four-week mark. Many people do not. Staying at 5 mg or 7.5 mg for longer is allowed by the label as long as you are on a maintenance dose or working toward one. The dosing chart video walks through the same schedule on camera.
Tirzepatide dosage in units: compounded vial math
Brand pens and single-dose vials are pre-measured, so there is no unit math. Compounded tirzepatide usually comes in a multi-dose vial, and you draw each dose with a U-100 insulin syringe. On that syringe, 1 mL equals 100 units. The only number that converts mg to units is the concentration on your vial label, written as mg/mL. Always confirm it with the pharmacy that filled the vial.
Check your GLP-1 eligibility
Use our free BMI Calculator to see if you may qualify for provider-reviewed GLP-1 therapy.
Try the BMI Calculator →The formula is: dose in mg divided by concentration in mg/mL equals mL. Then multiply mL by 100 to get units. At 10 mg/mL, 2.5 mg is 0.25 mL, which is 25 units.
| Weekly dose | 5 mg/mL | 10 mg/mL | 15 mg/mL | 20 mg/mL |
|---|---|---|---|---|
| 2.5 mg | 0.5 mL (50 units) | 0.25 mL (25 units) | 0.17 mL (about 17 units) | 0.125 mL (12.5 units) |
| 5 mg | 1.0 mL (100 units) | 0.5 mL (50 units) | 0.33 mL (about 33 units) | 0.25 mL (25 units) |
| 7.5 mg | 1.5 mL (150 units, two draws) | 0.75 mL (75 units) | 0.5 mL (50 units) | 0.375 mL (37.5 units) |
| 10 mg | 2.0 mL (200 units, two draws) | 1.0 mL (100 units) | 0.67 mL (about 67 units) | 0.5 mL (50 units) |
| 12.5 mg | 2.5 mL (250 units, three draws) | 1.25 mL (125 units, two draws) | 0.83 mL (about 83 units) | 0.625 mL (62.5 units) |
| 15 mg | 3.0 mL (300 units, three draws) | 1.5 mL (150 units, two draws) | 1.0 mL (100 units) | 0.75 mL (75 units) |
Source: arithmetic from the labeled dose strengths (Zepbound and Mounjaro prescribing information) and the U-100 syringe standard (1 mL = 100 units). The concentration on your vial controls.
Two things stand out. First, a 1 mL syringe holds 100 units, so any dose above 100 units needs two draws. Second, the 15 mg/mL and 20 mg/mL columns land on fractions of a unit. Most insulin syringes are marked in 1 or 2 unit steps, so ask your pharmacy how to round. Our tirzepatide dosing calculator guide explains the math in more depth, and the calculator does it for you.
Tirzepatide units to mg: reading the syringe backward
Searches like "how many mg is 40 units of tirzepatide" only have an answer once you know the concentration. This table uses the common 10 mg/mL example. If your vial is 5 mg/mL, halve the mg. If it is 20 mg/mL, double it.
| Units drawn | mL | mg at 10 mg/mL | Is this a labeled dose? |
|---|---|---|---|
| 20 units | 0.20 mL | 2 mg | No (below the 2.5 mg starting dose) |
| 25 units | 0.25 mL | 2.5 mg | Yes, starting dose |
| 30 units | 0.30 mL | 3 mg | No |
| 40 units | 0.40 mL | 4 mg | No |
| 50 units | 0.50 mL | 5 mg | Yes, maintenance dose |
| 60 units | 0.60 mL | 6 mg | No |
| 75 units | 0.75 mL | 7.5 mg | Yes, step-up dose |
| 100 units | 1.00 mL | 10 mg | Yes, maintenance dose |
Source: arithmetic at 10 mg/mL; labeled doses from the Zepbound prescribing information.
Doses like 3, 4 or 6 mg are not on the label. Some prescribers use in-between amounts with compounded vials. That is a prescriber decision, not something to do on your own. If your written prescription and your unit count do not match this math, call the pharmacy before you inject.
How much tirzepatide to start with
The label answer is 2.5 mg once a week for four weeks. That dose is meant to let your gut adjust, not to drive weight loss. The label calls it a starting dose and says it is not a maintenance dose. After four weeks, the next step is 5 mg. On a 10 mg/mL vial, that means 25 units for the first month, then 50 units.
Some people are told to stay on 2.5 mg longer, or to move up more slowly. Both are allowed. The label sets a minimum of four weeks per step, and no maximum. Nausea, diarrhea, vomiting and constipation are the most common reasons to slow down. In SURMOUNT-1 those effects were mostly mild to moderate and mostly happened during dose escalation.
Missed dose, early dose and changing your injection day
The prescribing information gives three timing rules. They apply to Zepbound and Mounjaro, and most prescribers use the same rules for compounded tirzepatide.
| Situation | Label rule |
|---|---|
| Missed a dose | Take it within 4 days (96 hours) of the missed day, then return to your usual day. |
| More than 4 days late | Skip the missed dose. Take the next dose on the regular day. |
| Two doses too close together | Never take two doses within 3 days (72 hours) of each other. |
| Changing your weekly day | Allowed, as long as the gap between two doses is at least 3 days (72 hours). |
Source: Zepbound and Mounjaro prescribing information, Dosage and Administration.
These rules work because tirzepatide has an elimination half-life of about 5 days and reaches steady state after 4 weeks of weekly dosing. A one-day shift changes very little. We cover the details in can you take tirzepatide a day early.
Tirzepatide maintenance dose
The Zepbound label names 5, 10 and 15 mg as maintenance doses. There is no rule that everyone must reach 15 mg. In SURMOUNT-1, the 5 mg group lost an average of 15.0% of body weight over 72 weeks, the 10 mg group 19.5%, and the 15 mg group 20.9%. The placebo group lost 3.1%. Higher doses gave more loss on average, but they also had more nausea and more people stopping for side effects (4.3% at 5 mg, 7.1% at 10 mg, 6.2% at 15 mg, versus 2.6% on placebo).
The right maintenance dose is the one that gives you steady progress with side effects you can live with. That is a conversation with your prescriber, not a chart lookup. See Zepbound doses for what each strength does.
Tirzepatide dosage chart in mL and storage
The mL column matters for two reasons. It tells you how many doses a vial holds, and it tells you when you need two draws. A 10 mg/mL vial holding 3 mL contains 30 mg, which is twelve 2.5 mg doses or six 5 mg doses. Your pharmacy's label will state the total mg and the volume.
For storage, the brand labels say to refrigerate at 2 to 8 C (36 to 46 F), never freeze, and protect from light. Brand pens and vials may sit unrefrigerated at up to 30 C (86 F) for up to 21 days. Compounded vials follow the beyond-use date and storage directions on the pharmacy label, which can be shorter. If your compounded vial arrived as a powder, see how to mix tirzepatide powder.
What this means for compounded tirzepatide
Compounded tirzepatide is not FDA approved and is not interchangeable with Zepbound or Mounjaro. The mg schedule above is the brand label's schedule; most prescribers apply it to compounded vials, but your prescriber sets your plan. The difference is the syringe math, which depends entirely on the vial concentration.
At FormBlends, compounded tirzepatide is $149 for the first month, then $239 a month, or $214 a month with Subscribe & Save. The price is the same at 2.5 mg or 15 mg, shipping and injection supplies are included, and lab work is not. Prescriptions are written by independent, state-licensed clinicians of Recess MD LLC, and medication is compounded by state-licensed 503A compounding pharmacies. See pricing or begin at start. If the provider does not prescribe, the charge is refunded.
Frequently Asked Questions
How many units is 5 mg of tirzepatide?
At 10 mg/mL, 5 mg is 0.5 mL, which is 50 units on a U-100 syringe. At 5 mg/mL it is 100 units, and at 20 mg/mL it is 25 units. Check the concentration on your vial before you draw.
How many mg is 40 units of tirzepatide?
At 10 mg/mL, 40 units is 0.4 mL, which is 4 mg. That is not one of the six labeled doses. If your prescription says 40 units, confirm the intended mg with your pharmacy or prescriber.
Is 25 units of tirzepatide a lot?
On a 10 mg/mL vial, 25 units is 2.5 mg, the labeled starting dose and the lowest strength made. On a 5 mg/mL vial it is only 1.25 mg, which is below the starting dose. The units alone do not tell you whether a dose is large or small.
How much tirzepatide should I start with?
The label starts every adult at 2.5 mg once a week for four weeks, then moves to 5 mg. Your prescriber may keep you at a step longer if you have side effects. Do not start at a higher dose on your own.
Is there a tirzepatide reconstitution chart?
Reconstitution charts show how much bacteriostatic water to add to a powder vial to reach a target concentration. Adding 1 mL of water to a 10 mg vial gives 10 mg/mL, and adding 2 mL gives 5 mg/mL. Your pharmacy's instructions control the volume, so use their number, not a chart from the internet.
Does the compounded tirzepatide dosage differ from Zepbound?
The mg amounts prescribers use are usually the same six strengths. What differs is the delivery: a pen or single-dose vial has no math, while a compounded multi-dose vial needs a syringe draw based on concentration. Compounded tirzepatide is not FDA approved and is not interchangeable with the brand.
Sources
- Zepbound (tirzepatide) prescribing information, Eli Lilly via DailyMed, revised 08/2026.
- Mounjaro (tirzepatide) prescribing information, Eli Lilly via DailyMed, revised 08/2026.
- Zepbound US prescribing information (PDF), Eli Lilly, 2026.
- Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1), Jastreboff et al., New England Journal of Medicine, 2022.
- FormBlends pricing, Form Blends LLC, verified September 5, 2026.
Next steps
Read how to microdose tirzepatide compound if your prescriber uses in-between doses, and bookmark the calculator for your own vial. Browse the tirzepatide hub for every other tirzepatide question. If your dose, units or vial label do not match, talk to a clinician or your pharmacist before you inject. Compounded tirzepatide is not FDA approved and is not interchangeable with Zepbound or Mounjaro; a licensed provider decides whether it is appropriate for you.
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