GLP-1 receptor agonist
Reconstitute injectable semaglutide (Ozempic, Wegovy) from a lyophilized vial and get the exact units to draw. Enter your vial strength, bacteriostatic water volume, and weekly dose for the precise mark on a U-100 insulin syringe.
Draw to
Draw to the 7.5 unit mark. That is 0.075 mL of solution.
Informational and educational only. Not medical advice. This tool performs math on values you enter and is not a substitute for your prescriber.
Units to draw are calculated from your current vial and water settings above and update live.
| Period | Dose | Draw (units) | Volume |
|---|---|---|---|
| Weeks 1-4current | 0.3 mg | 7.5 | 0.075 mL |
| Weeks 5-8 | 0.5 mg | 15 | 0.150 mL |
| Weeks 9-12 | 1 mg | 30 | 0.300 mL |
| Weeks 13-16 | 1.7 mg | 51 | 0.510 mL |
| Week 17+ | 2.4 mg | 72 | 0.720 mL |
Semaglutide has an elimination half-life of approximately one week, supporting once-weekly subcutaneous dosing. The drug remains present in circulation for about five weeks after the last dose. In December 2025 the FDA also approved an oral tablet form of Wegovy (semaglutide 25 mg once daily), the first oral GLP-1 approved for weight management. This calculator is for the injectable form (lyophilized powder you reconstitute); the oral tablet does not require reconstitution and is not covered here.
Source: FDA Ozempic (semaglutide) Prescribing Information - DailyMed
Add your chosen volume of bacteriostatic water to the lyophilized vial, directing the stream gently against the glass wall, and swirl slowly (do not shake) until fully dissolved. The calculator above converts your vial strength and water volume into the exact units to draw for your target dose.
It depends on your reconstitution concentration. With a 5 mg vial in 2 mL of bacteriostatic water (2.5 mg/mL), 0.25 mg is 0.10 mL, which is 10 units on a U-100 syringe. Enter your own vial size and water volume above to get your exact number.
The Wegovy (semaglutide for weight management) escalation schedule starts at 0.25 mg once weekly for four weeks, then increases every four weeks: 0.5 mg (weeks 5-8), 1.0 mg (weeks 9-12), 1.7 mg (weeks 13-16), and 2.4 mg from week 17 onward as the maintenance dose. This schedule is per the FDA Wegovy prescribing information; always follow your prescriber's instructions.
Semaglutide has an elimination half-life of approximately one week (about 165 hours), so it remains detectable in the body for roughly five weeks after the last injection. This long half-life is what makes once-weekly dosing effective.
Source: FDA Ozempic (semaglutide) Prescribing Information - DailyMed · How we calculate