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Tirzepatide reconstitution & dosage calculator.

Enter vial size (5–60 mg), BAC water volume, and weekly dose to get concentration, syringe units to draw, and doses per vial. Includes the 6-tier titration schedule (2.5–15 mg weekly), vial size comparison, and syringe capacity warnings. Verify tirzepatide quality with independent lab test data on Peptigrity.

§ Interactive calculatorLive lab data
Select Peptide
Vial size (mg)
Bacteriostatic water (mL)
Desired dose (mcg)= 2.50 mg
Syringe size
50.0u
0u
25u
50u
75u
100u
1.0 mL (100u)
50.0 unitsDraw to this mark on your 1.0 mL (100u) syringe
5000.0 mcg/mLConcentration
0.500 mLVolume per dose
4Doses per vial

Titration schedule

FDA-approved · 6 tiers

The FDA-approved titration protocol for tirzepatide (Mounjaro for type 2 diabetes, Zepbound for weight management) starts at 2.5 mg once weekly and increases by 2.5 mg every 4 weeks to a maximum of 15 mg weekly. Compounded lyophilised tirzepatide follows the same titration tiers.

TierWeekly doseWeeks@ 5 mg/mL@ 10 mg/mL@ 15 mg/mL
Tier 1 (start)2.5 mgWeeks 1–450 u25 u~17 u
Tier 25 mgWeeks 5–8100 u50 u~33 u
Tier 37.5 mgWeeks 9–12Exceeds75 u50 u
Tier 410 mgWeeks 13–16Exceeds100 u~67 u
Tier 512.5 mgWeeks 17–20ExceedsExceeds~83 u
Tier 6 (max)15 mgWeek 21+ExceedsExceeds100 u

At 5 mg/mL concentration (10 mg vial + 2 mL BAC water), doses above 5 mg exceed a standard 100-unit syringe's capacity. Users titrating beyond 5 mg must increase the concentration (use less BAC water) or split the dose across 2 draws. The calculator above flags syringe capacity warnings automatically.

How to reconstitute tirzepatide

5 steps · ~2–3 minutes
01
Gather supplies
Bacteriostatic water (0.9% benzyl alcohol), a U-100 insulin syringe (100-unit recommended for tirzepatide's larger draw volumes), and alcohol swabs. For a full supply guide, see reconstituting peptides step by step.
02
Choose your BAC water volume
This is the most consequential decision. Use 1 mL BAC water per 10 mg of tirzepatide (10 mg/mL) for doses up to 10 mg. For the full titration through 15 mg, target 15 mg/mL. The BAC water calculator recommends volumes based on your dose and syringe.
03
Add BAC water slowly
Inject water slowly against the inside glass wall — never spray directly onto the lyophilised powder. Direct impact can denature the peptide.
04
Dissolve gently
Tirzepatide dissolves readily within 1–2 minutes of gentle swirling. Do not shake. The solution should be clear and colourless when fully dissolved.
05
Refrigerate & label
Refrigerate at 2–8°C. Reconstituted tirzepatide remains stable for approximately 28 days. Label the vial with the compound name, reconstitution date, concentration, and discard date. For storage guidance, see how to store peptides.

Common tirzepatide vial sizes

Match vial to your protocol length
Vial size@ 2.5 mg/wk@ 5 mg/wk@ 10 mg/wk@ 15 mg/wkBest for
5 mg2 weeks1 weekTrial / starting dose
10 mg4 weeks2 weeks1 weekTiers 1–2
15 mg6 weeks3 weeks1.5 weeks1 weekSingle-tier coverage
30 mg12 weeks6 weeks3 weeks2 weeksMulti-week protocols
60 mg24 weeks12 weeks6 weeks4 weeksExtended protocols

Shelf life constraint: Reconstituted tirzepatide lasts approximately 28 days. Larger vials may outlast the stability window. Reconstitute only what you need for 4 weeks. For price comparisons, use the cost-per-dose calculator.

Tirzepatide vs semaglutide

Dosing differences at a glance
FactorTirzepatideSemaglutide
Receptor targetsDual: GIP + GLP-1GLP-1 only
Starting dose2.5 mg weekly0.25 mg weekly
Maintenance range5–15 mg weekly1.0–2.4 mg weekly
Maximum dose15 mg weekly2.4 mg weekly (Wegovy)
Titration steps+2.5 mg every 4 weeks+0.25–0.5 mg every 4 weeks
Common vial sizes5, 10, 15, 30, 60 mg2, 3, 5, 10 mg

Frequently asked questions

6 questions
How many units is 2.5 mg of tirzepatide?

At 5 mg/mL (10 mg vial + 2 mL BAC water), 2.5 mg = 50 units. At 10 mg/mL (10 mg vial + 1 mL BAC water), 2.5 mg = 25 units. At 15 mg/mL, 2.5 mg = approximately 17 units. Use the calculator above with your specific vial and BAC water volume for the exact draw.

How much bacteriostatic water should I add to a 10 mg tirzepatide vial?

1 mL produces 10 mg/mL — suitable for doses up to 10 mg in a single 100-unit draw. 2 mL produces 5 mg/mL — easier to measure small starting doses (2.5 mg = 50 units) but exceeds syringe capacity above 5 mg. Choose based on your current and planned titration tier.

Does tirzepatide need to be refrigerated after reconstitution?

Reconstituted tirzepatide stored at 2–8°C (standard refrigerator) remains stable for approximately 28 days. Unreconstituted lyophilised powder stored at −20°C maintains integrity for 3–6 months.

What is the difference between Mounjaro, Zepbound, and compounded tirzepatide?

All three contain the same 39-amino-acid dual GIP/GLP-1 receptor agonist. Mounjaro is FDA-approved for type 2 diabetes. Zepbound is approved for weight management. Both ship as pre-filled pens. Compounded tirzepatide is produced by pharmacies under FDA 503A/503B regulations as lyophilised powder requiring reconstitution.

How do I convert tirzepatide mg to syringe units?

Divide your dose (in mg) by the concentration (in mg/mL), then multiply by 100. Example: 5 mg ÷ 10 mg/mL = 0.5 mL × 100 = 50 units. The calculator performs this conversion automatically.

How many doses do I get from a 30 mg tirzepatide vial?

At 2.5 mg/week: 12 doses. At 5 mg/week: 6 doses. At 10 mg/week: 3 doses. At 15 mg/week: 2 doses. However, reconstituted tirzepatide is stable for approximately 28 days — so plan reconstitution in portions if your protocol extends beyond that.

This calculator is for educational and research purposes only and does not constitute medical advice. Tirzepatide is an FDA-approved prescription medication (Mounjaro, Zepbound). Compounded tirzepatide is produced under FDA 503A/503B regulations and requires a prescription. Always consult a qualified healthcare provider for dosing guidance. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.