If you draw semaglutide from a vial with an insulin syringe, the number of units you draw depends entirely on your vial’s concentration (mg per mL) — the same milligram amount is a different unit count at different strengths. This page shows the conversion for the standard dose steps at common concentrations, and how to run the exact numbers for your vial. It is mixing-math, not a dosing recommendation; confirm your dose with your prescriber and read the mg/mL on your own label.
On a U-100 insulin syringe, 100 units = 1 mL. So:
Remember 1 mg = 1000 mcg. Slipping between mg and mcg is the most common serious error in this whole process.
Illustrative only — the concentration that matters is the one printed on YOUR label. This is not a recommendation to take any dose.
| Dose | 2.5 mg/mL | 5 mg/mL | 10 mg/mL |
|---|---|---|---|
| 0.25 mg | 10 units | 5 units | 2.5 units |
| 0.5 mg | 20 units | 10 units | 5 units |
| 1.0 mg | 40 units | 20 units | 10 units |
| 1.7 mg | 68 units | 34 units | 17 units |
| 2.4 mg | 96 units | 48 units | 24 units |
Say a vial is labeled 5 mg/mL and the dose your prescriber set is 0.5 mg: 0.5 ÷ 5 = 0.1 mL, and 0.1 mL × 100 = 10 units on a U-100 syringe. Change the concentration and the unit count changes — which is exactly why you must read your own label.
A clean whole-number draw is easier to measure accurately, and it keeps you far from the two dangerous mistakes: a 10× or 100× miscount (usually an mg/mcg mix-up), and reading a U-40 syringe as if it were U-100. If your number lands between marks or looks off by a factor of ten, stop and recheck the concentration before you draw.
You can compute the exact units for any vial and dose — including one that gives a clean draw — with the free reconstitution calculator.
No. It only converts a milligram amount into a syringe mark at a given concentration. The dose itself is a medical decision made with your prescriber, and the concentration must be read from your own vial’s label.
It is the mg per mL, either printed on the label or worked out from the vial’s total mg and the water you added: concentration = vial mg × 1000 ÷ water mL, in mg per mL.
Brand pens are pre-dosed, so units do not apply. Compounded vials vary in concentration, so always use the mg/mL on your specific vial rather than assuming a value.
That is fine — read the nearest mark carefully. Some people choose a water volume that makes the draw a round number; the calculator can solve for that.
U-40 syringes are marked at 40 units per mL instead of 100, so the same volume reads as a different unit number. Match the syringe to the math, and never mix U-40 and U-100 marks.