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Semaglutide reconstitution calculator.
Reconstituting a lyophilized semaglutide vial? Enter the mg in the vial, the bacteriostatic water you add, and your target dose. You get the exact concentration, the volume to draw in mL, and the units on a U-100 syringe. No rounding, no account, and the full math is shown.
Units shown for a U-100 insulin syringe (1 mL = 100 units). No rounding · the full math is above.
How the math works
Three steps, no hand-waving.
Reconstitution is simple arithmetic. The only thing that matters is that it is exact, and that you can see every step.
Vial mg ÷ BAC water mL = mg/mL. A 5 mg vial in 2 mL of water is 2.5000 mg/mL.
Target dose ÷ concentration = mL to draw. 250 mcg ÷ 2.5000 mg/mL = 0.1000 mL.
Draw mL × 100 = units on a U-100 insulin syringe. 0.1000 mL = 10 units.
Background
What semaglutide reconstitution is
Semaglutide is a GLP-1 receptor agonist. When supplied as a lyophilized (freeze-dried) powder, it has to be reconstituted with bacteriostatic water before any dose can be drawn. The reconstitution math is identical to any peptide: concentration is the mg in the vial divided by the mL of water you add. This calculator does that arithmetic exactly so you can see your draw volume and syringe units.
- Reconstitution built into the dose logger, not a separate tool
- 28-day BAC water expiry countdown per vial
- Doses remaining and refill warnings, all derived
- Local-first · no account, data stays on your device
FAQ
Semaglutide reconstitution questions, answered.
How do you calculate semaglutide reconstitution?
Divide the mg of semaglutide in the vial by the mL of bacteriostatic water you add to get the concentration in mg/mL. Then divide your target dose (in mg) by that concentration to get the volume to draw in mL. Multiply that volume by 100 for units on a U-100 insulin syringe.
How much bacteriostatic water do I add to semaglutide?
There is no single correct amount. More water means a lower concentration and a larger, easier-to-measure draw volume; less water means a higher concentration and a smaller draw. Enter whatever you actually plan to add and the calculator shows the resulting draw. Follow your provider's or compounding pharmacy's instructions.
How many units of semaglutide is my dose?
Units depend on your concentration. Enter your vial mg, BAC water mL, and target dose above and the calculator returns the exact units on a U-100 syringe. The result updates live as you change any value.
How do I convert semaglutide mcg to mg?
1 mg equals 1000 mcg, so a 250 mcg dose is 0.25 mg. Enter your dose in whichever unit your protocol uses; the calculator converts before solving, so both entries return the same draw volume.
Why does getting the exact semaglutide dose matter?
At these concentrations a small volume error is a large dose error. The FDA has documented cases of people drawing five to twenty times the intended amount from compounded vials, with serious adverse events. Showing the draw volume and units to four decimal places is how this tool reduces the guesswork. Always confirm your numbers with your provider or pharmacist.
How should reconstituted semaglutide be stored?
Follow the storage guidance for your specific product. Reconstituted vials are generally refrigerated and used within a limited window. Regimio tracks a per-vial expiry countdown so you are not guessing how many days are left.
Is compounded semaglutide still legal?
Compounded semaglutide was widely available mainly because the FDA-approved drug was in shortage. The FDA declared that shortage resolved in February 2025, so routine compounding is no longer generally permitted, with only a narrow patient-specific exception. This is a regulatory summary, not legal advice; our compounded semaglutide explainer covers the detail.
Is this medical advice?
No. This is a reconstitution calculator that performs arithmetic on the values you enter. It does not recommend a dose, a schedule, or a source. Confirm all medication instructions with your clinician or pharmacist.
- 1Semaglutide compound summary. PubChem, US National Library of Medicine
- 2FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss. U.S. Food & Drug Administration
This tool performs reconstitution arithmetic only. It is not medical advice and does not recommend any compound, dose, schedule, or source. Always follow guidance from a qualified provider. See our medical disclaimer.