GLP-1 Reconstitution & Dose Calculator: Semaglutide & Tirzepatide
The semaglutide reconstitution calculator and tirzepatide reconstitution calculator in one tool. Enter your vial size, BAC water volume, and target dose to get exact insulin syringe units. Works for 2 mg, 5 mg, 10 mg, 15 mg, 30 mg, and 60 mg vials of compounded semaglutide, tirzepatide, and retatrutide.
Peptide Reconstitution Calculator
Calculate your exact dose
Enter your vial details to calculate how many units to draw for your dose.
Common doses: Semaglutide (0.25-2.4mg), Tirzepatide (2.5-15mg)
Draw syringe to
100 units
(1.00 mL)
Concentration:
2,500 mcg/mL
Doses per vial:
2
Keep this dose in Regimen — get a weekly reminder and see how you respond.
Add to RegimenFor educational and research purposes only. This calculator provides estimates based on standard formulas.
Always verify calculations with your healthcare provider before use. We assume no liability for dosing errors, adverse events, or outcomes resulting from use of this tool.
How to Use This Calculator
Enter vial size
The mg amount on your GLP-1 vial (e.g., 5mg, 10mg)
Enter BAC water
How much bacteriostatic water you added (typically 2mL)
Enter weekly dose
Your target dose in mg (e.g., 0.25mg, 0.5mg, 2.5mg)
Read your result
See exactly how many units to draw on your syringe
How to Calculate Your GLP-1 Injection Dose
If you're using compounded semaglutide or tirzepatide (not pre-filled pens like Ozempic or Mounjaro), you need to calculate how many units to draw on your insulin syringe based on your vial's concentration and your prescribed dose.
The formula:
Units to draw = Prescribed dose (mg) ÷ Concentration (mg/mL) x 100
Example: Your compounded semaglutide is 5mg/2mL (2.5mg/mL). Your prescribed dose is 0.25mg.
0.25 ÷ 2.5 x 100 = 10 units
Semaglutide Titration Schedule
Semaglutide is typically titrated (gradually increased) to reduce side effects. Here's the standard titration:
| Week | Weekly Dose | Purpose |
|---|---|---|
| Weeks 1-4 | 0.25mg | Starting dose, let your body adjust |
| Weeks 5-8 | 0.5mg | First increase |
| Weeks 9-12 | 1.0mg | Second increase |
| Weeks 13-16 | 1.7mg | Third increase (Wegovy protocol) |
| Week 17+ | 2.4mg | Maintenance dose (Wegovy protocol) |
Your provider may adjust this schedule based on your response and tolerance. Use the calculator above to recalculate your syringe units at each dose increase. Regimen's GLP-1 titration planner maps out your full titration schedule with dates.
Tirzepatide Titration Schedule
| Week | Weekly Dose | Purpose |
|---|---|---|
| Weeks 1-4 | 2.5mg | Starting dose |
| Weeks 5-8 | 5mg | First increase |
| Weeks 9-12 | 7.5mg | Second increase |
| Weeks 13-16 | 10mg | Third increase |
| Weeks 17-20 | 12.5mg | Fourth increase |
| Week 21+ | 15mg | Maximum dose |
Titrate only when your provider recommends it. Not everyone reaches the maximum dose.
Track Your GLP-1 Progress
Calculating your dose is step one. Tracking whether it's working is step two.
Log every injection
in Regimen — dose, timing, and injection site.
Track your weight and body fat
automatically through Apple Health or Google Health Connect.
Monitor side effects
over time — see if nausea decreases as your body adjusts to each dose level.
Visualize your medication levels
between weekly injections with Regimen's half-life visualizer.
Example GLP-1 Calculations
Common dosing scenarios for compounded semaglutide and tirzepatide
What This GLP-1 Calculator Does
This calculator is designed for compounded versions of GLP-1 receptor agonists — the kind that come as lyophilized powder in vials rather than pre-filled pens. If you're using compounded semaglutide (the active ingredient in Ozempic and Wegovy) or compounded tirzepatide (Mounjaro and Zepbound), you need to reconstitute the powder with bacteriostatic water before injecting.
Enter your vial size, how much BAC water you added, and your prescribed dose. The calculator converts your dose into exact insulin syringe units so you draw the right amount every time. It also works for retatrutide and other emerging GLP-1 compounds.
Semaglutide reconstitution calculator
For compounded semaglutide, the most common vials are 2 mg, 5 mg, and 10 mg. The 5 mg vial reconstituted with 2 mL of BAC water gives a clean 2.5 mg/mL concentration that maps neatly to every standard titration step (0.25 mg = 10 units, 0.5 mg = 20 units, 1.0 mg = 40 units, 2.4 mg = 96 units on a 100-unit insulin syringe). Larger 10 mg vials in 2 mL or 3 mL are common for maintenance doses.
Tirzepatide reconstitution calculator
Compounded tirzepatide ships in larger vials — typically 10 mg, 15 mg, 30 mg, and 60 mg. A 30 mg vial in 1.5 mL gives 20 mg/mL, where 2.5 mg = 12.5 units and 15 mg = 75 units. Enter your specific vial size and BAC water volume above to skip the math.
Need help building a dose escalation timeline? Learn more in our GLP-1 tracker guide
Related GLP-1 Tools
GLP-1 Titration Planner
Get a personalized dose escalation schedule with exact dates
Tirzepatide-specific reconstitution calculator
Vial size and BAC water to insulin units, with a draw-to-here syringe diagram
Retatrutide-specific reconstitution calculator
5-30mg vial presets, U-100 syringe selector, and a draw-to-here syringe diagram
Peptide Calculator
Calculate doses for BPC-157, TB-500, and other peptides
GLP-1 Dosing Questions
Data Sources
This tool uses dosing information from official prescribing information:
- •Reconstitution Math — Standard concentration and volume calculations for peptide reconstitution
- •GLP-1 Dosing Guidelines — Typical titration schedules for semaglutide and tirzepatide
- •Insulin Syringe Standards — U-100 syringe conversion: 100 units = 1mL
Track your GLP-1 journey
Regimen has a built-in dose calculator plus weekly reminders, weight tracking, and progress photos.
- Built-in dose calculator
- Weekly injection reminders
- Track weight over time
- Progress photo timeline
