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How-to · reconstitution
In this example, 2 mL of bacteriostatic water in a 10 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 | 10.00 mg/mL | 100 mcg | 2.5 units |
| 2 mL | 5.00 mg/mL | 50 mcg | 5.0 units |
Straight arithmetic: concentration = 10 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 10 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 | 10.00 mg/mL | 2.5 units |
| 2 mL | 5.00 mg/mL | 5.0 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 | 10.00 mg/mL | 17.0 to 24.0 units |
| 2 mL | 5.00 mg/mL | 34.0 to 48.0 units |
FDA labelWegovy (semaglutide) — FDA-approved Prescribing Information (DailyMed) · retrieved 2026-08-20
This is the largest semaglutide vial size in these guides. It contains forty worked doses; the smaller water example gives a fractional-unit reading, while the larger gives a whole-unit result.
Using the smaller water amount puts the worked draw between two and three units. That fraction has no matching whole-unit line in the illustration. The larger water amount doubles the draw and lands on a whole unit.
Keep the exact result when checking the calculation. Rounding up or down changes the drug amount; it is not just a cosmetic change to the number.
At the same total water volume, more drug in the vial means more drug in each syringe unit. A reading from one of the smaller semaglutide vials would therefore represent a different dose here.
Check the drug amount and liquid volume before comparing unit counts. If the medication arrives as a prepared solution, use its labeled concentration rather than treating this powder example as instructions to add water.
The theoretical dose count is large because the example dose is small relative to the vial content. It does not prove that this product can be kept through forty administrations, or that any particular fraction will expire unused.
Actual storage and disposal limits belong to the dispensed formulation and container. Use those instructions when estimating supply or cost. The calculator can show the quantity at a chosen dose, but vial size alone cannot establish stability, sterility or a suitable treatment plan.
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.