Reconstitution charts
Tirzepatide reconstitution chart: vial × water → units
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Short answer
Concentration = vial mg ÷ water mL; U-100 units = dose mg ÷ concentration × 100. Example: 30 mg in 3 mL is 10 mg/mL, so 2.5 mg is 25 units. This applies only to powder vials, which are compounded or research products, not FDA approved. Zepbound and Mounjaro come as ready-to-use solutions. As of Oct 19, 2026.
On this page10 sections
| Item | Value | Source |
|---|---|---|
| FDA-approved single-dose pen or vial | Ready-to-use solution, 2.5 to 15 mg per 0.5 mL | DailyMed, Aug 28, 2026 |
| FDA-approved multi-dose vial and KwikPen | 4 doses, 10 to 60 mg per 2.4 mL (4.17 to 25 mg/mL) | DailyMed, Aug 28, 2026 |
| Label appearance | Clear, colorless to slightly yellow solution | DailyMed, Aug 28, 2026 |
| Compounded tirzepatide | Not FDA approved; not reviewed for safety, effectiveness or quality | FDA, Oct 1, 2026 |
| Adverse-event reports, compounded tirzepatide | More than 730 reports as of May 31, 2026 | FDA, Oct 1, 2026 |
| Shortage first declared resolved | October 2, 2024 | FDA, Dec 19, 2024 |
| Shortage resolution reaffirmed | December 19, 2024 | FDA, Dec 19, 2024 |
| 503B outsourcing facility discretion ended | March 19, 2025 | FDA, Dec 19, 2024 |
Also useful: Tirzepatide mg to units, Pen-to-vial converter.
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Vial and water
30 mg + 3 mL
The mg in the vial never changes; water only sets how spread out it is.
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Concentration
30 ÷ 3 = 10 mg/mL
Milligrams in every milliliter of solution.
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Units on a U-100 syringe
2.5 mg ÷ 10 = 0.25 mL = 25 U
100 units = 1 mL, so units = mL × 100 (rounded to 0.5 U).
Search for a tirzepatide reconstitution chart and you will find tables that assume tirzepatide comes as a powder. The FDA-approved products do not. This page gives the arithmetic for powder vials, shows where the brand products fit, and states plainly what the FDA says about the products that need mixing.
Approved products are solutions, not powders
| Presentation | Contents | Concentration | Mixing needed |
|---|---|---|---|
| Single-dose pen | 2.5, 5, 7.5, 10, 12.5 or 15 mg in 0.5 mL | 5, 10, 15, 20, 25 or 30 mg/mL | No |
| Single-dose vial | 2.5, 5, 7.5, 10, 12.5 or 15 mg in 0.5 mL | 5, 10, 15, 20, 25 or 30 mg/mL | No |
| Multi-dose vial | 10, 20, 30, 40, 50 or 60 mg in 2.4 mL (4 doses) | 4.17, 8.33, 12.5, 16.7, 20.8 or 25 mg/mL | No |
| Single-patient-use KwikPen | 10 to 60 mg in 2.4 mL (4 doses) | 4.17 to 25 mg/mL | No |
The label describes the product as a “clear, colorless to slightly yellow solution.” Each single-dose pen or vial holds one weekly dose in 0.5 mL, and each multi-dose vial or KwikPen holds four doses of 0.6 mL. There is no water to add and no concentration to choose. If you use a brand product, the pen-to-vial converter and the tirzepatide dosage chart are more relevant than this page.
Who the reconstitution math applies to
Reconstitution means adding a sterile diluent, usually bacteriostatic water, to a freeze-dried (lyophilized) powder. For tirzepatide, that describes two kinds of product:
- Compounded tirzepatide made by a pharmacy. The FDA says compounded drugs are not FDA approved and that the agency “does not review compounded drugs for safety, effectiveness or quality before they are marketed.” (FDA, Oct 1, 2026)
- Research-labeled vials, which are not approved for human use at all.
Neither is interchangeable with Zepbound or Mounjaro. The FDA also reports that, as of May 31, 2026, it had received more than 730 adverse-event reports associated with compounded tirzepatide, and its consumer page describes dosing errors with compounded GLP-1 products. (FDA, Oct 1, 2026) Unit math is one place those errors happen, which is why the arithmetic below is shown in full.
The two formulas
- Concentration (mg/mL) = vial strength (mg) ÷ water added (mL).
- Units on a U-100 scale = dose (mg) ÷ concentration (mg/mL) × 100.
U-100 means 100 units per mL, so 1 unit is 0.01 mL. Units here are a volume mark, not a measure of drug strength. The same 2.5 mg dose can be 8 units or 75 units depending on how much water went into the vial.
Worked example, 30 mg vial with 3 mL:
- Concentration: 30 ÷ 3 = 10 mg/mL.
- 2.5 mg: 2.5 ÷ 10 × 100 = 25 units (0.25 mL).
- 5 mg: 5 ÷ 10 × 100 = 50 units (0.5 mL).
- 15 mg: 15 ÷ 10 × 100 = 150 units, which is 1.5 mL and does not fit the 100-unit scale.
Concentration chart: vial × water
| Vial | 1 mL water | 2 mL water | 3 mL water |
|---|---|---|---|
| 10 mg | 10 mg/mL | 5 mg/mL | 3.33 mg/mL |
| 15 mg | 15 mg/mL | 7.5 mg/mL | 5 mg/mL |
| 20 mg | 20 mg/mL | 10 mg/mL | 6.67 mg/mL |
| 30 mg | 30 mg/mL | 15 mg/mL | 10 mg/mL |
| 40 mg | 40 mg/mL | 20 mg/mL | 13.33 mg/mL |
| 60 mg | 60 mg/mL | 30 mg/mL | 20 mg/mL |
Two cells line up with the label. A 10 mg vial in 2 mL gives 5 mg/mL, the same concentration as the 2.5 mg/0.5 mL single-dose pen. A 60 mg vial in 2 mL gives 30 mg/mL, the same as the 15 mg/0.5 mL pen. Equal concentration does not make the products equivalent; the brand product is the one the FDA reviewed.
| Vial | 1 mL water | 2 mL water | 3 mL water |
|---|---|---|---|
| 10 mg | 25 U | 50 U | 75 U |
| 15 mg | 16.7 U | 33.3 U | 50 U |
| 20 mg | 12.5 U | 25 U | 37.5 U |
| 30 mg | 8.3 U | 16.7 U | 25 U |
| 40 mg | 6.3 U | 12.5 U | 18.8 U |
| 60 mg | 4.2 U | 8.3 U | 12.5 U |
The pattern is the main safety point. Small water volumes in large vials produce single-digit unit counts, where a one-unit misread is a large share of the dose. At 60 mg in 1 mL, 1 unit is 0.6 mg.
Full units matrix for each vial
Each table below covers one vial size. Rows are the six label dose strengths; columns are water volumes. Cells above 100 units are left blank because the volume would exceed 1 mL.
U-100 units for tirzepatide doses of 2.5 to 15 mg by powder vial size (mg) and water volume (mL). Arithmetic only: concentration = vial mg ÷ water mL; units = dose mg ÷ concentration × 100. FDA-approved Zepbound and Mounjaro are ready-to-use solutions and are not reconstituted.
| Dose | 1 mL water10 mg/mL | 2 mL water5 mg/mL | 3 mL water3.333 mg/mL |
|---|---|---|---|
| 2.5 mg | 25 U | 50 U | 75 U |
| 5 mg | 50 U | 100 U | — |
| 7.5 mg | 75 U | — | — |
| 10 mg | 100 U | — | — |
| 12.5 mg | — | — | — |
| 15 mg | — | — | — |
| Dose | 1 mL water15 mg/mL | 2 mL water7.5 mg/mL | 3 mL water5 mg/mL |
|---|---|---|---|
| 2.5 mg | 16.5 U (raw 16.67) | 33.5 U (raw 33.33) | 50 U |
| 5 mg | 33.5 U (raw 33.33) | 66.5 U (raw 66.67) | 100 U |
| 7.5 mg | 50 U | 100 U | — |
| 10 mg | 66.5 U (raw 66.67) | — | — |
| 12.5 mg | 83.5 U (raw 83.33) | — | — |
| 15 mg | 100 U | — | — |
| Dose | 1 mL water20 mg/mL | 2 mL water10 mg/mL | 3 mL water6.667 mg/mL |
|---|---|---|---|
| 2.5 mg | 12.5 U | 25 U | 37.5 U |
| 5 mg | 25 U | 50 U | 75 U |
| 7.5 mg | 37.5 U | 75 U | — |
| 10 mg | 50 U | 100 U | — |
| 12.5 mg | 62.5 U | — | — |
| 15 mg | 75 U | — | — |
| Dose | 1 mL water30 mg/mL | 2 mL water15 mg/mL | 3 mL water10 mg/mL |
|---|---|---|---|
| 2.5 mg | 8.5 U (raw 8.33) | 16.5 U (raw 16.67) | 25 U |
| 5 mg | 16.5 U (raw 16.67) | 33.5 U (raw 33.33) | 50 U |
| 7.5 mg | 25 U | 50 U | 75 U |
| 10 mg | 33.5 U (raw 33.33) | 66.5 U (raw 66.67) | 100 U |
| 12.5 mg | 41.5 U (raw 41.67) | 83.5 U (raw 83.33) | — |
| 15 mg | 50 U | 100 U | — |
| Dose | 1 mL water40 mg/mL | 2 mL water20 mg/mL | 3 mL water13.333 mg/mL |
|---|---|---|---|
| 2.5 mg | 6.5 U (raw 6.25) | 12.5 U | 19 U (raw 18.75) |
| 5 mg | 12.5 U | 25 U | 37.5 U |
| 7.5 mg | 19 U (raw 18.75) | 37.5 U | 56.5 U (raw 56.25) |
| 10 mg | 25 U | 50 U | 75 U |
| 12.5 mg | 31.5 U (raw 31.25) | 62.5 U | 94 U (raw 93.75) |
| 15 mg | 37.5 U | 75 U | — |
| Dose | 1 mL water60 mg/mL | 2 mL water30 mg/mL | 3 mL water20 mg/mL |
|---|---|---|---|
| 2.5 mg | 4 U (raw 4.17) | 8.5 U (raw 8.33) | 12.5 U |
| 5 mg | 8.5 U (raw 8.33) | 16.5 U (raw 16.67) | 25 U |
| 7.5 mg | 12.5 U | 25 U | 37.5 U |
| 10 mg | 16.5 U (raw 16.67) | 33.5 U (raw 33.33) | 50 U |
| 12.5 mg | 21 U (raw 20.83) | 41.5 U (raw 41.67) | 62.5 U |
| 15 mg | 25 U | 50 U | 75 U |
Units = dose mg ÷ (vial mg ÷ water mL) × 100, rounded to the nearest 0.5 U; the raw value is shown in brackets when rounding changed it. A dash means the draw would exceed a 100-unit syringe or the vial. Arithmetic only; not dosing advice.
To run one combination at a time, use the tirzepatide reconstitution calculator. To convert a dose at a known concentration, use the tirzepatide units calculator.
How many doses a vial holds
Doses per vial is vial mg ÷ dose mg, independent of water volume.
| Vial | 2.5 mg | 5 mg | 10 mg | 15 mg |
|---|---|---|---|---|
| 10 mg | 4 | 2 | 1 | 0 |
| 20 mg | 8 | 4 | 2 | 1 |
| 30 mg | 12 | 6 | 3 | 2 |
| 60 mg | 24 | 12 | 6 | 4 |
For comparison, each FDA-approved multi-dose vial and KwikPen holds exactly four doses of one strength and is discarded after 4 weekly doses, 30 days after first use, or 30 days at room temperature, whichever comes first. (DailyMed, Aug 28, 2026) A compounded vial carries whatever dating its pharmacy assigns; the FDA has not reviewed it.
The regulatory timeline behind compounded tirzepatide
Compounded tirzepatide spread while the brand product was in shortage. The FDA timeline:
| Date | Event |
|---|---|
| December 15, 2022 | Tirzepatide injection added to the FDA drug shortage list |
| October 2, 2024 | FDA determines the shortage is resolved and removes it from the list |
| December 19, 2024 | After reevaluation, FDA reaffirms that the shortage is resolved |
| March 19, 2025 | End of enforcement discretion for 503B outsourcing facilities |
The memo also set an earlier end date for 503A pharmacies in February 2025. We could not read the exact day in the FDA’s file, so we do not state it.
Printing this chart
This page has a print stylesheet. Printing it, or saving it as PDF from your browser’s print dialog, keeps the formulas, the concentration table and each units matrix, and drops the navigation. If you print it, keep the date with it: the regulatory facts are current as of October 19, 2026. More background on brands, approvals and trials is on the tirzepatide hub.
None of this replaces a prescription label. If a pharmacy dispensed your product, its label and your prescriber set the concentration and the volume, and they are the people to ask.
Frequently asked questions
Tirzepatide reconstitution chart: how does it work?
- Two formulas. Concentration (mg/mL) = vial mg ÷ water mL. Units on a U-100 scale = dose mg ÷ concentration × 100. A 30 mg vial in 3 mL is 10 mg/mL, so 2.5 mg is 25 units and 5 mg is 50 units. The chart applies to powder (lyophilized) vials only; FDA-approved Zepbound and Mounjaro come as ready-to-use solutions.
How much bac water to mix with 30 mg tirzepatide?
- There is no single answer; the water volume only sets the concentration. 1 mL gives 30 mg/mL, 2 mL gives 15 mg/mL and 3 mL gives 10 mg/mL. At those strengths a 2.5 mg dose is 8.3, 16.7 or 25 units. A 30 mg powder vial is not an FDA-approved product, so the volume should come from the prescription label of a licensed pharmacy, not from a chart.
Do you need to reconstitute Zepbound or Mounjaro?
- No. The FDA labels describe every presentation (single-dose pen, single-dose vial, multi-dose vial and KwikPen) as a clear, colorless to slightly yellow solution. Single-dose strengths are 2.5 to 15 mg per 0.5 mL. Nothing is added before use.
Is there a tirzepatide reconstitution chart PDF?
- This page is the printable version. It has a print stylesheet, so printing it or saving it as PDF from your browser keeps the formula, the concentration table and every units matrix on paper. For a single vial and water volume, the tirzepatide reconstitution calculator gives the same numbers.
Is compounded tirzepatide FDA approved?
- No. The FDA says compounded drugs are not FDA approved and that it does not review them for safety, effectiveness or quality before they are marketed. The FDA declared the tirzepatide shortage resolved on October 2, 2024 and reaffirmed that on December 19, 2024. Compounded products are not interchangeable with Zepbound or Mounjaro.
Sources
- ZEPBOUND (tirzepatide) injection, for subcutaneous use - Full Prescribing Information, Medication Guide and Instructions for Use (DailyMed SPL set ID 487cd7e7-434c-4925-99fa-aa80b1cc776b, version 40). U.S. National Library of Medicine (DailyMed) / Eli Lilly and Company, Aug 28, 2026. Accessed Oct 19, 2026.
- MOUNJARO (tirzepatide) injection, for subcutaneous use - Full Prescribing Information, Medication Guide and Instructions for Use (DailyMed SPL set ID d2d7da5d-ad07-4228-955f-cf7e355c8cc0, version 40). U.S. National Library of Medicine (DailyMed) / Eli Lilly and Company, Aug 27, 2026. Accessed Oct 19, 2026.
- FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. U.S. Food and Drug Administration, Oct 1, 2026. Accessed Oct 19, 2026.
- Resolution of Tirzepatide Injection Product Shortage and Supply Status (CDER Drug Shortage Staff memorandum). U.S. Food and Drug Administration, Dec 19, 2024. Accessed Oct 19, 2026.