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Semaglutide Reconstitution Calculator

A GLP-1 receptor agonist sold as Ozempic and Wegovy, injected once a week. Enter your vial size, the water you add, and your dose to see the units to draw. Defaults: 5 mg vial, 2 mL water, 250 mcg per dose.

Math only. The dose itself comes from your prescriber or protocol; this page does not recommend one.

Excel: the button above exports this calculation as a spreadsheet with live formulas, or download the blank template.

How to reconstitute Semaglutide

Semaglutide is sold as a freeze-dried powder, most often in 2 mg, 3 mg, 5 mg, 10 mg vials. Add bacteriostatic water, let it dissolve without shaking, and the concentration is the vial amount divided by the water: 5 mg in 2 mL is 2.5 mg/mL. On a U-100 insulin syringe one unit is 0.01 mL, so each unit carries 25 mcg, and a 250 mcg dose is 10 units.

The Wegovy label starts at 0.25 mg once weekly for four weeks and steps through 0.5, 1, 1.7 and 2.4 mg; Ozempic tops out at 2 mg. Nothing on this page is a dosing recommendation; the calculator converts a dose you already have into syringe units.

Semaglutide doses in syringe units (5 mg vial, 2 mL water)

DoseUnitsmLDoses per vial
250 mcg100.120
500 mcg200.210
1 mg400.45
1.7 mg680.682
2.4 mg960.962

Vial sizes at 250 mcg per dose

VialWaterConcentrationUnits per doseDoses
2 mg2 mL1 mg/mL258
3 mg2 mL1.5 mg/mL16.712
5 mg2 mL2.5 mg/mL1020
10 mg2 mL5 mg/mL540

The dose column is in mg. Doubling the water halves the concentration and doubles the units per dose; the number of doses in the vial never changes. If a dose comes out under 5 units, use less water so it is easier to measure. If it exceeds the syringe, use more water or a bigger syringe.

Worked example

5 mg / 2 mL = 2.5 mg/mL = 2,500 mcg/mL. One unit = 0.01 mL = 25 mcg. 250 mcg / 25 mcg per unit = 10 units. The vial holds 5,000 / 250 = 20 doses, which at 1 per week is about 140 days.

See the general peptide calculator for the formulas, syringe sizes, and the common mg versus mcg mistakes.

Frequently asked questions

How many units is 250 mcg of Semaglutide?

With 5 mg in 2 mL of bacteriostatic water the concentration is 2.5 mg/mL, each unit holds 25 mcg, and 250 mcg is 10 units (0.1 mL). Change the water and the units change with it.

How much bacteriostatic water do I add to a 5 mg vial of Semaglutide?

Any volume gives the same doses; 2 mL is a common choice because it keeps 250 mcg at 10 units, which is easy to read on an insulin syringe. Use the calculator's round-number table to pick a volume that fits your syringe.

How long does a 5 mg vial of Semaglutide last?

At 250 mcg per dose the vial holds 20 doses. At 1 dose a week that is about 140 days. Reconstituted vials are usually refrigerated and used within about four weeks.

What is the Semaglutide dose?

The Wegovy label starts at 0.25 mg once weekly for four weeks and steps through 0.5, 1, 1.7 and 2.4 mg; Ozempic tops out at 2 mg. This calculator only converts a dose you already have into syringe units.

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