Page last checked
How-to · reconstitution
In this example, 1 mL of bacteriostatic water in a 5 mg Semaglutide vial gives 5.00 mg/mL. An example 0.25 mg amount is then 5.0 units on a U-100 syringe.
This example lands on a syringe line. More water makes a weaker mix and a bigger draw. Less water makes a stronger mix and a smaller one. The amount of Semaglutide stays the same. Use the diluent and volume specified for your product; the arithmetic alone does not choose them.
| Water added | Concentration | Per U-100 unit | Example: 0.25 mg = |
|---|---|---|---|
| 1 mL | 5.00 mg/mL | 50 mcg | 5.0 units |
| 2 mL | 2.50 mg/mL | 25 mcg | 10.0 units |
Straight arithmetic: concentration = 5 mg ÷ liquid volume, and 1 U-100 unit = 0.01 mL. The example column shows the math at 0.25 mg; it is not a dose recommendation.
The table compares possible concentrations; it does not establish which diluent or volume suits your product. Follow its dispensing instructions.
“Hard to measure” means the example draw is below two U-100 units. “Won’t fit” means it exceeds this syringe’s capacity.
Semaglutide is the drug in Wegovy, Ozempic and Rybelsus. It copies a gut hormone called GLP-1, which helps control appetite and blood sugar.
The table above uses one worked example. These are the published quantities, converted into marks on a U-100 barrel at each listed liquid volume for a 5 mg vial. Where a quantity was never studied by injection, the row says so.
0.25 mg once weekly for 4 weeks, under the skin.
| Water added | Concentration | Draw |
|---|---|---|
| 1 mL | 5.00 mg/mL | 5.0 units |
| 2 mL | 2.50 mg/mL | 10.0 units |
FDA labelWegovy (semaglutide) — FDA-approved Prescribing Information (DailyMed) · retrieved 2026-08-20
1.7–2.4 mg once weekly, under the skin.
| Water added | Concentration | Draw, low to high |
|---|---|---|
| 1 mL | 5.00 mg/mL | 34.0 to 48.0 units |
| 2 mL | 2.50 mg/mL | 68.0 to 96.0 units |
FDA labelWegovy (semaglutide) — FDA-approved Prescribing Information (DailyMed) · retrieved 2026-08-20
Both displayed water amounts give whole-unit syringe readings at the example dose. The vial divides into twenty doses before losses, but that count does not establish how long it can be used.
The larger water amount spreads the same drug content through twice as much liquid. Each dose then needs twice the draw volume. Both results land on whole-unit lines in the illustration, with no rounding needed for these inputs.
The dose itself has not doubled. This distinction matters when comparing two labels or screenshots that show different unit readings for the same amount of medication.
The smaller draw uses only a few units. A difference of one line can therefore represent a substantial fraction of that reading. Whole units make the calculation tidy, but they do not remove the need to check the syringe and concentration.
Use the scale printed on the supplied syringe. The U-100 drawing is not a generic measurement scale for every device, and the water examples do not override the mixing instructions.
The dose count is obtained by division. It assumes the same dose each time and does not account for residual liquid, storage limits or restrictions on repeated use of the container.
A disposal date and the number of usable doses cannot be inferred from that count. Check the pharmacy label for the prepared product. A cost estimate based on all twenty portions needs those practical limits before it can describe the amount you could actually use.
The calculator lets you enter your product’s vial strength and mixing volume, then shows the arithmetic for your syringe.
Open the Semaglutide calculator →The arithmetic on this page is only half the question. These are the pages that carry the other half.