Reconstitution and syringe units
Semaglutide Calculator
Convert a semaglutide dose in mg into units on a U-100 insulin syringe for any vial and concentration.
Semaglutide calculator
Example values are loaded. Replace them with the numbers on your own vial.
Approved semaglutide and where this math applies
Semaglutide is a GLP-1 receptor agonist, FDA-approved as Ozempic and Wegovy (injections) and Rybelsus and Wegovy tablets. Branded pens are pre-filled and dial the dose for you. Unit math matters for compounded or lyophilized vials, where you draw the dose with an insulin syringe.
The FDA declared the semaglutide shortage resolved in February 2025, which ended the period in which pharmacies could compound near-copies of the drug under shortage rules. Compounded semaglutide may still be prescribed in some specific situations; your pharmacist can tell you what applies to you.
Label dose steps (Wegovy injection)
According to the Wegovy prescribing information, treatment starts at 0.25 mg once weekly for 4 weeks, then steps up every 4 weeks to 0.5 mg, 1 mg and 1.7 mg. The recommended maintenance dose is 2.4 mg once weekly, with 1.7 mg as an alternative, and the current label adds a 7.2 mg weekly option for adults who have tolerated 2.4 mg and need more weight loss. Your prescriber sets your dose.
Units chart: 2.5 mg/mL
A 5 mg vial with 2 mL of water gives 2.5 mg/mL, a common concentration for compounded semaglutide. Each unit holds 0.025 mg (25 mcg).
| Dose | Units (U-100) | mL |
|---|---|---|
| 250 mcg | 10 | 0.1 |
| 500 mcg | 20 | 0.2 |
| 1 mg | 40 | 0.4 |
| 1.7 mg | 68 | 0.68 |
| 2.4 mg | 96 | 0.96 |
Units chart: 5 mg/mL
| Dose | Units (U-100) | mL |
|---|---|---|
| 250 mcg | 5 | 0.05 |
| 500 mcg | 10 | 0.1 |
| 1 mg | 20 | 0.2 |
| 1.7 mg | 34 | 0.34 |
| 2.4 mg | 48 | 0.48 |
Pre-mixed vials
Compounded semaglutide is often supplied already in solution, labelled with a concentration such as 2.5 mg/mL. Enter it as 2.5 mg of peptide with 1 mL of water. Some compounded products also contain added ingredients such as vitamin B12; those do not change the semaglutide math as long as the label gives the semaglutide concentration.
Frequently asked questions
How many units is 0.25 mg of semaglutide?
At 2.5 mg/mL, 0.25 mg is 10 units. At 5 mg/mL, it is 5 units.
How many units is 1 mg of semaglutide?
At 2.5 mg/mL, 1 mg is 40 units. At 5 mg/mL, it is 20 units.
Is compounded semaglutide the same as Ozempic or Wegovy?
No. Compounded products are not FDA-approved and are not reviewed for safety, effectiveness or quality the way approved drugs are.