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How-to · reconstitution
In this example, 2 mL of bacteriostatic water in a 2 mg Semaglutide vial gives 1.00 mg/mL. An example 0.25 mg amount is then 25.0 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 | 2.00 mg/mL | 20 mcg | 12.5 units |
| 2 mL | 1.00 mg/mL | 10 mcg | 25.0 units |
Straight arithmetic: concentration = 2 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 2 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 | 2.00 mg/mL | 12.5 units |
| 2 mL | 1.00 mg/mL | 25.0 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 | 2.00 mg/mL | 85.0 to 120.0 unitswon’t fit |
| 2 mL | 1.00 mg/mL | 170.0 to 240.0 unitswon’t fit |
FDA labelWegovy (semaglutide) — FDA-approved Prescribing Information (DailyMed) · retrieved 2026-08-20
The worked amount divides this vial into eight complete doses. Of the two water examples, the larger volume produces a whole-unit reading and the smaller one ends between whole-unit marks.
The count depends on the dose as well as the vial strength. A small worked dose can divide even this vial into several portions. It does not mean that each portion can be stored and used over the following weeks.
The arithmetic assumes the full stated drug content and no loss during handling. It also does not check whether the supplied container is intended for one use or several.
That reading sits between whole-unit lines on the illustrated scale. Doubling the water doubles the liquid needed for the same amount of drug, which gives the whole-unit result in the other row.
This comparison explains the numbers; it is not a reason to dilute a dispensed product differently from its instructions. Check the actual syringe markings and ask the pharmacist about a draw that cannot be measured as written.
A semaglutide ingredient name does not identify the preparation or its storage requirements. Branded devices and pharmacy-prepared products can have different instructions, and a powder-mixing example does not replace those instructions.
No universal use-by period is attached to the eight-dose estimate. For an actual prescription, read the concentration, dose, preparation method and disposal date together. If any of those details is missing, the count in this table cannot supply it.
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.