HomePeptide dosagesTirzepatide
Tirzepatide dosage: chart, label schedule and vial math
Tirzepatide is injected under the skin once a week. The US and Canadian labels start at 2.5 mg for 4 weeks, then 5 mg, and allow steps of 2.5 mg no sooner than every 4 weeks, up to a maximum of 15 mg a week. These are the label doses for Mounjaro and Zepbound.
Legal status
US Approved, prescription
Canada Authorized, prescription
Checked 10 Oct 2026What is Tirzepatide?Tirzepatide dosage chart
Label schedulePick your vial size. Each row shows the dose in milligrams or micrograms, the volume to draw and the mark on a U-100 syringe.
| When | Dose | Volume | Syringe units |
|---|---|---|---|
| Weeks 1 to 4 | 2.5 mg | 0.25 mL | 25 units |
| Weeks 5 to 8 | 5 mg | 0.50 mL | 50 units |
| Weeks 9 to 12 | 7.5 mg | 0.75 mL | 75 units |
| Weeks 13 to 16 | 10 mg | 1.00 mL | 100 units |
Source Schedule from the FDA label (earliest step-up allowed). The label goes on to 12.5 mg and 15 mg. Vial math is arithmetic.
Which syringe fits each dose
For the 20 mg vial at 10 mg/mL.
| Dose | Volume | Units | 0.3 mL syringe | 0.5 mL syringe | 1 mL syringe |
|---|---|---|---|---|---|
| 2.5 mg | 0.25 mL | 25 units | Yes | Yes | Yes |
| 5 mg | 0.50 mL | 50 units | No | Yes | Yes |
| 7.5 mg | 0.75 mL | 75 units | No | No | Yes |
| 10 mg | 1.00 mL | 100 units | No | No | Yes |
How long a vial lasts
Whole doses in one vial. The row for the size picked above is marked.
| Vial | 2.5 mg | 5 mg | 7.5 mg | 10 mg |
|---|---|---|---|---|
| 5 mg vial | 2 doses | 1 dose | Not enough | Not enough |
| 20 mg vial | 8 doses | 4 doses | 2 doses | 2 doses |
| 30 mg vial | 12 doses | 6 doses | 4 doses | 3 doses |
How to mix a Tirzepatide vial
These steps are for the 20 mg vial picked in the chart. Change the size there and the amounts here change with it.
- Wash your hands. Wipe the stopper of the peptide vial and the water vial with an alcohol swab.
- Draw 2 mL of bacteriostatic water into a syringe.
- Push the needle through the stopper of the peptide vial and let the water run slowly down the glass, not straight onto the powder.
- Swirl the vial gently until the powder is gone. Do not shake it.
- Write the date and 10 mg/mL on the vial, then put it in the fridge.
| Vial | Bacteriostatic water | Concentration |
|---|---|---|
| 5 mg vial | 1 mL | 5 mg/mL |
| 20 mg vial | 2 mL | 10 mg/mL |
| 30 mg vial | 3 mL | 10 mg/mL |
What Tirzepatide is
Tirzepatide is a glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist, sold as a once-weekly injection under the skin. [1]
Other names: LY3298176, Mounjaro, Zepbound.
How it has been given to people: subcutaneous injection, once weekly.
What to know before reading a dose
- Mounjaro and Zepbound are the same drug under two names with different approved uses. The labels say not to combine tirzepatide products or use one with a GLP-1 receptor agonist.
- Both US labels carry a boxed warning about thyroid C-cell tumors seen in rats.
- The label maximum is 15 mg once weekly for adults in both countries. No approved schedule goes higher.
- FDA says it has received more than 730 adverse event reports tied to compounded tirzepatide as of May 31, 2026, and warns about unapproved versions sold as research products [12].
Doses on record for Tirzepatide
Every dose below was given in a human study or printed on an approved label, and each links to its source. Doses set by body weight are left that way.
| From | Where it was used | Dose | How often | For how long | Source |
|---|---|---|---|---|---|
| Label | Zepbound (US), starting dose | 2.5 mg | once weekly | first 4 weeks | [2] |
| Label | Zepbound (US), step after the first 4 weeks; lowest maintenance dose for weight | 5 mg | once weekly | at least 4 weeks before any further step | [2] |
| Label | Zepbound (US), escalation step between 5 mg and 10 mg; not a listed maintenance dose | 7.5 mg | once weekly | at least 4 weeks | [2] |
| Label | Zepbound (US), maintenance dose for weight or sleep apnea | 10 mg | once weekly | ongoing | [2] |
| Label | Zepbound (US), escalation step between 10 mg and 15 mg; not a listed maintenance dose | 12.5 mg | once weekly | at least 4 weeks | [2] |
| Label | Zepbound (US), maintenance dose and maximum | 15 mg | once weekly | ongoing | [2] |
| Label | Mounjaro (US), starting dose | 2.5 mg | once weekly | at least 4 weeks before any step up | [1] |
| Label | Mounjaro (US), maximum for pediatric patients | 10 mg | once weekly | ongoing | [1] |
| Label | Mounjaro (US), maximum for adults | 15 mg | once weekly | ongoing | [1] |
| Human study | Phase 3 SURMOUNT-1 | 5 mg | once weekly | 72 weeks including a 20-week dose-escalation period | [3] |
| Human study | Phase 3 SURMOUNT-1 | 10 mg | once weekly | 72 weeks including a 20-week dose-escalation period | [3] |
| Human study | Phase 3 SURMOUNT-1 | 15 mg | once weekly | 72 weeks including a 20-week dose-escalation period | [3] |
| Human study | Phase 3b SURMOUNT-5, head to head with semaglutide, maximum tolerated dose | 10 mg | once weekly | 72 weeks | [4] |
| Human study | Phase 3b SURMOUNT-5, head to head with semaglutide, maximum tolerated dose | 15 mg | once weekly | 72 weeks | [4] |
| Human study | Phase 3 SURPASS-2 | 5 mg | once weekly | 40 weeks | [5] |
| Human study | Phase 3 SURPASS-2 | 10 mg | once weekly | 40 weeks | [5] |
| Human study | Phase 3 SURPASS-2 | 15 mg | once weekly | 40 weeks | [5] |
| Human study | Phase 3 SURMOUNT-OSA, maximum tolerated dose | 10 mg | once weekly | 52 weeks | [6] |
| Human study | Phase 3 SURMOUNT-OSA, maximum tolerated dose | 15 mg | once weekly | 52 weeks | [6] |
| Human study | Phase 3 SURPASS-CVOT, dose taken up to 15 mg | up to 15 mg | once weekly | event-driven cardiovascular outcomes trial; length not stated in the abstract | [7] |
What the evidence shows
Each finding is tagged by the kind of study it comes from. Human trials are listed first.
Randomized human trial
In adults with obesity or overweight and no diabetes, mean weight change at 72 weeks was -15.0% on 5 mg and -19.5% on 10 mg. [3]
Randomized human trial
In the same trial mean weight change was -20.9% on 15 mg, against -3.1% on placebo. [3]
Randomized human trial
Head to head in adults with obesity and no type 2 diabetes, weight fell 20.2% on tirzepatide and 13.7% on semaglutide at 72 weeks. [4]
Randomized human trial
In type 2 diabetes, glycated hemoglobin fell 2.01, 2.24 and 2.30 percentage points on 5 mg, 10 mg and 15 mg at 40 weeks, against 1.86 on semaglutide 1 mg. [5]
Randomized human trial
In adults with obstructive sleep apnea and obesity not using positive airway pressure, the apnea-hypopnea index fell by 25.3 events per hour on tirzepatide and 5.3 on placebo at 52 weeks. [6]
Randomized human trial
In type 2 diabetes with cardiovascular disease, tirzepatide was noninferior to dulaglutide for cardiovascular death, heart attack or stroke. [7]
Side effects and warnings
Reported in human studies or on a label:
- Zepbound label, reactions reported in 5% or more of patients: nausea, diarrhea, vomiting, constipation, abdominal pain, indigestion, injection site reactions, fatigue, hypersensitivity reactions, belching, hair loss and reflux. [2]
- Mounjaro label, reactions reported in 5% or more of patients: nausea, diarrhea, decreased appetite, vomiting, constipation, indigestion and abdominal pain. [1]
- In SURMOUNT-1 the most common adverse events were gastrointestinal, mostly mild to moderate, and came mainly while the dose was being raised. [3]
- In SURMOUNT-1, adverse events led to stopping treatment in 4.3% on 5 mg, 7.1% on 10 mg and 6.2% on 15 mg, against 2.6% on placebo. [3]
From the label
- Boxed warning on both US labels: tirzepatide caused thyroid C-cell tumors in rats. [2]
- Whether it causes these tumors, including medullary thyroid carcinoma, in people is not known. [2]
- Not for anyone with a personal or family history of medullary thyroid carcinoma (MTC), or with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). [2]
- Not for anyone with a known serious hypersensitivity to tirzepatide or to an ingredient in the product. [2]
- Not recommended together with another tirzepatide product or any GLP-1 receptor agonist. [2]
- The 2.5 mg dose is for starting treatment and is not an approved maintenance dose. [2]
- It slows stomach emptying, which can change how other medicines taken by mouth are absorbed. [2]
- Oral birth control: the label advises switching to a non-oral method or adding a barrier method for 4 weeks after starting and for 4 weeks after each dose increase. [2]
- With insulin or a sulfonylurea the risk of low blood sugar goes up; the label says to consider lowering the dose of those medicines. [2]
- Missed dose (both US labels): take it as soon as possible within 4 days (96 hours). After 4 days, skip it and take the next dose on the usual day. [2]
Storage
Zepbound (US): refrigerate at 2 to 8 C (36 to 46 F) in the original carton. Do not freeze. Protect from heat and light. A single-dose pen or vial may be kept unrefrigerated, at no more than 30 C (86 F), for up to 21 days in total. [2]
Tirzepatide dosage questions
How many units is 5 mg of Tirzepatide from a 20 mg vial?
Mixed with 2 mL of bacteriostatic water, a 20 mg vial is 10 mg/mL. 5 mg is 0.50 mL, which is 50 units on a U-100 syringe.
How much water goes in a 20 mg Tirzepatide vial?
2 mL gives 10 mg/mL. At that strength the doses in the chart sit at 25, 50, 75, 100 units on a U-100 syringe.
How many doses are in a 20 mg vial?
Whole doses in one vial: 8 at 2.5 mg, 4 at 5 mg, 2 at 7.5 mg, 2 at 10 mg.
Is Tirzepatide approved in the US?
FDA approved as Mounjaro (13 May 2022) and Zepbound (8 November 2023).
Is Tirzepatide authorized in Canada?
Authorized by Health Canada as Mounjaro and Zepbound, both listed as marketed in the Drug Product Database.
What is the half-life of Tirzepatide?
About 5 days.
What does the Mounjaro label say about dose?
Start at 2.5 mg once weekly. If more glycemic control is needed, go up in 2.5 mg steps after at least 4 weeks on the current dose. Maximum 15 mg once weekly in adults, 10 mg once weekly in pediatric patients.
Sources
Each one was opened on 10 Oct 2026 and matched to the line it supports.
- Mounjaro (tirzepatide) injection, US prescribing information, Eli Lilly and Company, label version 40 2026-08-27. dailymed.nlm.nih.gov.
- Zepbound (tirzepatide) injection, US prescribing information, Eli Lilly and Company, label version 40 2026-08-28. dailymed.nlm.nih.gov.
- Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med 2022. PubMed 35658024. Trial NCT04184622.
- Aronne LJ et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. N Engl J Med 2025. PubMed 40353578. Trial NCT05822830.
- Frias JP et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. N Engl J Med 2021. PubMed 34170647. Trial NCT03987919.
- Malhotra A et al. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity. N Engl J Med 2024. PubMed 38912654. Trial NCT05412004.
- Nicholls SJ et al. Cardiovascular Outcomes with Tirzepatide versus Dulaglutide in Type 2 Diabetes. N Engl J Med 2025. PubMed 41406444. Trial NCT04255433.
- Drugs@FDA via openFDA: applications with generic name tirzepatide api.fda.gov.
- Health Canada Drug Product Database: products with active ingredient tirzepatide, with status lookups health-products.canada.ca.
- Mounjaro (tirzepatide injection) Canadian product monograph, Eli Lilly Canada Inc., date of authorization 2026-06-23 2026-06-23. pdf.hres.ca.
- Zepbound (tirzepatide injection) Canadian product monograph, Eli Lilly Canada Inc., date of authorization 2026-06-11 2026-06-11. pdf.hres.ca.
- FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss (content current as of 10/01/2026) fda.gov.
Looked for and not found
- Canadian product monographs were opened for the indications and the dose schedule only. Warnings, side effects, missed-dose and storage text in this file come from the US labels.
- Length of treatment in SURPASS-CVOT is not stated in the PubMed abstract.
Change log
10 Oct 2026Page published. 12 sources checked. Vial math added for the 5 and 20 and 30 mg vials.
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