Semaglutide Reconstitution Calculator: Dose & Syringe Units

Worked examples

5 mg vial, 2 mL water, 0.25 mg dose

Concentration = 5 ÷ 2 = 2.5 mg/mL. Volume = 0.25 ÷ 2.5 = 0.1 mL = 10 units on a U-100 syringe. About 20 starter doses per vial.

5 mg vial, 2 mL water, 0.5 mg dose

Same 2.5 mg/mL concentration. Volume = 0.5 ÷ 2.5 = 0.2 mL = 20 units. About 10 doses per vial.

10 mg vial, 2 mL water, 1 mg dose

Concentration = 10 ÷ 2 = 5 mg/mL. Volume = 1 ÷ 5 = 0.2 mL = 20 units. About 10 doses per vial.

Reading the titration off units

With a 5 mg vial in 2 mL (2.5 mg/mL), every unit is 25 mcg. So 0.25 mg is 10 units, 0.5 mg is 20 units, 1 mg is 40 units: the same syringe, just a different mark.

Reconstituting semaglutide, step by step

Semaglutide is a GLP-1 receptor agonist. Compounded and research-grade vials come as a freeze-dried powder that must be reconstituted with bacteriostatic water before any dose can be drawn. Semaglutide doses are small, often a fraction of a milligram, which makes the concentration you choose especially important for measuring accurately.

The three steps

Concentration = vial (mg) ÷ water (mL). A 5 mg vial in 2 mL of bacteriostatic water is 2.5 mg/mL.
Volume = dose (mg) ÷ concentration (mg/mL). A 0.25 mg dose at 2.5 mg/mL is 0.25 ÷ 2.5 = 0.1 mL.
Units = volume (mL) × 100. 0.1 mL is 10 units on a U-100 insulin syringe.

Making small doses readable

Because semaglutide is commonly titrated upward in small steps, pick a water volume that keeps each step on a round unit count. In the 5 mg + 2 mL example every unit carries 25 mcg, so 0.25 mg is 10 units, 0.5 mg is 20 units, and 1 mg is 40 units, all on the same syringe. The calculator reports micrograms per unit so you can double-check before drawing.

Doses per vial

Divide the vial size by your dose to see how long it lasts. A 5 mg vial at 0.25 mg per dose gives 20 doses; at 0.5 mg it gives 10. The water volume does not affect this count.

Important safety note

Semaglutide is a prescription medication, and research-grade or compounded vials are not approved for human use. This calculator performs reconstitution arithmetic only; it does not recommend a dose, a titration plan, or whether semaglutide is right for you, and it cannot judge safety. Treat every result as an educational estimate, not medical advice. Check the amount on your vial label, consult a licensed medical professional before acting, and follow all applicable laws.

Frequently asked questions

How do I reconstitute semaglutide?

Add bacteriostatic water to the lyophilized powder, then divide the milligrams in the vial by the millilitres of water to get the concentration. Divide your target dose by that concentration for the volume, and multiply by 100 for units on a U-100 insulin syringe. The calculator runs all three steps and draws the fill line.

How much bacteriostatic water for a semaglutide vial?

The water volume is your choice and only sets the concentration. A 5 mg vial with 2 mL of water gives 2.5 mg/mL, which makes a 0.25 mg starter dose land on a clean 10 units. Adding more water spreads the same peptide across more units per dose; adding less concentrates it into fewer.

Semaglutide doses are tiny; how do I measure them?

That is exactly why concentration matters. By choosing a water volume that puts your dose on a round number of units, a small dose becomes easy to read on the syringe. The calculator shows micrograms per unit so you can confirm each unit's amount before you draw.

Is this semaglutide calculator medical advice?

No. It only performs reconstitution math. It does not recommend a dose, a titration schedule, or whether semaglutide is appropriate for you. Semaglutide is a prescription medicine, and research-grade vials are not approved for human use. Talk to a licensed medical professional and follow all applicable laws.