MyPeptideMatchTirzepatide Reconstitution Calculator
Calculate the exact insulin syringe units for your compounded tirzepatide dose. Enter your vial size, bacteriostatic water volume, and weekly dose for an instant, precise reading — for 5 mg, 10 mg, and 15 mg vials.
Also called: tirzepatide calculatortirzepatide units calculatortirzepatide dosage calculator
Tirzepatide dosage chart — mg to syringe units
Look up your tirzepatide dose in the left column and find the corresponding units based on your reconstitution concentration. All values use a standard U-100 (1 mL) insulin syringe. Values marked with * exceed one syringe and require split injections — confirm the approach with your prescriber.
| Dose | 5 mg/mL10 mg + 2 mL | 7.5 mg/mL15 mg + 2 mL | 2.5 mg/mL10 mg + 4 mL | Typical Use |
|---|---|---|---|---|
| 2.5 mg | 50 units | 33 units | 100 units | Starting dose (weeks 1–4) |
| 5 mg | 100 units | 67 units | 200 units* | Titration dose (weeks 5–8) |
| 7.5 mg | 150 units* | 100 units | 300 units* | Titration dose (weeks 9–12) |
| 10 mg | 200 units* | 133 units* | 400 units* | Maintenance dose |
| 12.5 mg | 250 units* | 167 units* | 500 units* | Higher maintenance |
| 15 mg | 300 units* | 200 units* | 600 units* | FDA-approved Zepbound max dose |
* Values exceeding 100 units require splitting into multiple injections. Consult your prescriber for the recommended injection approach at higher doses.
Dosing Calculation Example: Tirzepatide 2.5 mg starting dose
Here is how the calculation works for the most common tirzepatide starting setup.
You have a 10 mg vial of compounded tirzepatide and add 2 mL of bacteriostatic water. Your starting dose is 2.5 mg (2,500 mcg) weekly using a 1 mL (100-unit) insulin syringe.
- Concentration: 10 mg ÷ 2 mL = 5.0 mg/mL
- Dose volume: 2,500 mcg ÷ 5,000 mcg/mL = 0.5 mL
- Syringe units: 0.5 mL × 100 = 50 units
- Doses per vial: 10,000 mcg ÷ 2,500 mcg = 4 weekly doses (1 month)
How to reconstitute compounded tirzepatide
Compounded tirzepatide is supplied as lyophilized (freeze-dried) powder. Always follow your prescribing clinician's or compounding pharmacy's instructions.
Gather supplies
Tirzepatide vial (lyophilized powder), bacteriostatic water (BAC water), sterile U-100 insulin syringes, 70% isopropyl alcohol swabs, and a sharps container.
Bring vials to room temperature
Allow both the tirzepatide vial and the bacteriostatic water to sit at room temperature for 15–30 minutes before mixing to prevent foaming and incomplete dissolution.
Swab and inject BAC water slowly
Swab both rubber stoppers with a fresh alcohol swab and let air-dry. Draw the correct BAC water volume and inject slowly into the tirzepatide vial, aiming the stream along the inner glass wall at a 45° angle — not directly at the powder.
Gently swirl until clear
Slowly rotate or swirl the vial until the solution is completely clear. Do not shake. Tirzepatide may take several minutes to fully dissolve. A cloudy or particulate solution should not be injected.
Label and refrigerate
Mark the vial with the reconstitution date. Store at 2–8°C (36–46°F). Most reconstituted tirzepatide with bacteriostatic water is stable for 3–4 weeks refrigerated — follow your pharmacy's specific guidance.
For a complete reconstitution guide covering all peptides, read how to reconstitute peptides.
Frequently asked questions
Common questions about tirzepatide reconstitution, dose calculations, and syringe units.
How many units is 2.5 mg of tirzepatide?
It depends on your concentration. At 5 mg/mL (10 mg vial + 2 mL BAC water): 2.5 mg = 0.5 mL = 50 units on a U-100 syringe. At 2.5 mg/mL (10 mg vial + 4 mL): 2.5 mg = 1.0 mL = 100 units. Use the calculator above for the exact units for your specific setup.
How much bacteriostatic water do I add to a 10 mg tirzepatide vial?
A common setup is 2 mL of bacteriostatic water into a 10 mg tirzepatide vial, yielding a 5 mg/mL concentration. At this concentration, the starting dose of 2.5 mg equals 50 units on a U-100 syringe. Some clinicians recommend 3–4 mL for a more dilute solution, which is easier to measure accurately for smaller doses. Always follow your prescribing provider's specific instructions.
How many units is 5 mg of tirzepatide?
At 5 mg/mL (10 mg + 2 mL BAC water): 5 mg = 1.0 mL = 100 units (full syringe). At 7.5 mg/mL (15 mg + 2 mL): 5 mg = 0.67 mL ≈ 67 units. The calculator above handles any configuration instantly.
How many units is 7.5 mg of tirzepatide?
At 5 mg/mL (10 mg + 2 mL): 7.5 mg = 1.5 mL — this exceeds a single 1 mL syringe, so you may split into two injections or use a larger tirzepatide vial. At 7.5 mg/mL (15 mg + 2 mL): 7.5 mg = 1.0 mL = 100 units. At 5 mg/mL (15 mg + 3 mL): 7.5 mg = 1.5 mL. Check your specific setup with the calculator above.
How many units is 10 mg of tirzepatide?
At 5 mg/mL (15 mg + 3 mL): 10 mg = 2.0 mL — typically split into two 1 mL (100-unit) injections. At 7.5 mg/mL (15 mg + 2 mL): 10 mg ≈ 1.33 mL ≈ 133 units — also typically split. For high-dose tirzepatide, confirm the injection volume and technique with your prescribing clinician.
How do I reconstitute a 15 mg tirzepatide vial?
For a 15 mg tirzepatide vial, a common setup is 2 mL of BAC water (7.5 mg/mL) or 3 mL (5 mg/mL). At 7.5 mg/mL, a 2.5 mg starting dose = 0.33 mL ≈ 33 units. At 5 mg/mL, 2.5 mg = 0.5 mL = 50 units. Select your vial size and water volume in the calculator above for your exact reading.
How long does reconstituted tirzepatide last?
Compounded tirzepatide reconstituted with bacteriostatic water is typically stable for 3–4 weeks when stored refrigerated at 2–8°C (36–46°F). For longer storage, freeze aliquots at -20°C (up to 3 months). Always follow your compounding pharmacy's specific stability guidance, which takes precedence over general estimates.
What needle and syringe do I use for tirzepatide injections?
Most tirzepatide injections are administered subcutaneously using a 29G or 31G insulin syringe with a ½-inch needle. For larger dose volumes (above 0.5 mL), use a 1 mL (100-unit) syringe. Inject into the lower abdomen, thigh, or upper arm, rotating sites with each injection.
What is the difference between tirzepatide and semaglutide dosing?
Tirzepatide is a dual GIP/GLP-1 agonist measured in milligrams (mg) per dose, with a typical starting dose of 2.5 mg/week. Semaglutide is a GLP-1 agonist starting at 0.25 mg/week. Because tirzepatide doses are significantly larger in mg, the injection volumes tend to be larger as well, even when both are reconstituted at the same concentration. Always confirm your specific dose and concentration with your prescriber.
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Medical Disclaimer: This tirzepatide reconstitution calculator is provided for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. All dosing should be determined and supervised by a licensed healthcare provider. Compounded tirzepatide is not equivalent to FDA-approved brand-name tirzepatide products (Mounjaro/Zepbound). Always consult your prescriber.