Quick math example
A 5 mg vial mixed with 2 mL gives 2.5 mg/mL. A 0.25 mg dose is 0.1 mL, which equals 10 units on a U-100 syringe.
Reconstitution reference
U100 units to draw for each common Semaglutide dose, by vial size, reconstituted with 2 mL of bacteriostatic water. Change the water volume in the calculator above to recompute for your own setup.
| Vial | Concentration | 250 mcg | 500 mcg | 1 mg | 1.7 mg | 2.4 mg |
|---|---|---|---|---|---|---|
| 2.5 mg | 1.25 mg/mL | 20 u(0.2 mL) | 40 u(0.4 mL) | 80 u(0.8 mL) | 136 u(1.36 mL) | 192 u(1.92 mL) |
| 5 mg | 2.5 mg/mL | 10 u(0.1 mL) | 20 u(0.2 mL) | 40 u(0.4 mL) | 68 u(0.68 mL) | 96 u(0.96 mL) |
| 10 mg | 5 mg/mL | 5 u(0.05 mL) | 10 u(0.1 mL) | 20 u(0.2 mL) | 34 u(0.34 mL) | 48 u(0.48 mL) |
Educational reference only — not a dose recommendation. Units assume a U100 insulin syringe (100 units = 1 mL on U-100). Always confirm against your own vial, diluent, and clinician or pharmacy instructions.
How the semaglutide calculation works
The calculator first converts the vial amount from mg to mcg, then divides by the BAC water volume to find concentration. Your target dose is divided by that concentration to return mL and syringe units.
For GLP-1 compounds, small dose changes can meaningfully change the draw volume. Re-run the calculation whenever vial size, water amount, syringe type, or target dose changes.
- Concentration = vial mcg / water mL
- Dose volume = target dose mcg / concentration
- U-100 units = dose volume mL x 100
Semaglutide 5 mg vial with 2 mL example
A 5 mg semaglutide vial mixed with 2 mL gives a concentration of 2.5 mg/mL, or 2,500 mcg/mL.
A 0.25 mg dose is 250 mcg. At 2,500 mcg/mL, that dose is 0.1 mL, which equals 10 units on a U-100 syringe.
- 5 mg / 2 mL = 2.5 mg/mL
- 0.25 mg = 250 mcg
- 250 mcg / 2,500 mcg per mL = 0.1 mL = 10 U-100 units
Semaglutide 10 mg vial with 2 mL example
A 10 mg semaglutide vial mixed with 2 mL gives a concentration of 5 mg/mL, or 5,000 mcg/mL.
A 0.5 mg dose is 500 mcg. At 5,000 mcg/mL, that dose is 0.1 mL, which equals 10 U-100 units.
- 10 mg / 2 mL = 5 mg/mL
- 0.5 mg = 500 mcg
- 500 mcg / 5,000 mcg per mL = 0.1 mL = 10 U-100 units
Use with compounded or lyophilized vials
This page is intended for situations where you need to calculate a dose from a vial and diluent volume. Pre-filled commercial pens usually do not require this math.
Follow the label, pharmacy directions, and clinician instructions for storage, titration, and beyond-use dates.
Frequently asked questions
Does this calculator tell me what semaglutide dose to take?+
Why do the units change when I change syringe type?+
Should I use bacteriostatic water?+
Primary sources
Full reference listBackground references for this calculator. PepSync does not make clinical claims; these citations support the educational context only.
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