Semaglutide Concentration Calculator

The Math Behind the Units

Compounded semaglutide comes as a lyophilized powder in vials — most commonly 2mg, 3mg, 5mg, and 10mg. You add bacteriostatic water to reconstitute it. The volume of BAC water you add determines the concentration, which determines how many units you draw per dose.

Concentration (mg/mL) = Vial size (mg) ÷ BAC water added (mL)
Draw units = (Dose in mg ÷ Concentration) × 100

Common Dose Tables

2mg vial + 2mL BAC water = 1mg/mL concentration

• 0.25mg dose = 25 units
• 0.5mg dose = 50 units
• 1mg dose = 100 units (full syringe)

5mg vial + 2mL BAC water = 2.5mg/mL concentration

• 0.25mg dose = 10 units
• 0.5mg dose = 20 units
• 1mg dose = 40 units
• 1.7mg dose = 68 units
• 2.4mg dose = 96 units

10mg vial + 2mL BAC water = 5mg/mL concentration

• 0.25mg dose = 5 units
• 0.5mg dose = 10 units
• 1mg dose = 20 units
• 2.4mg dose = 48 units

Tirzepatide (Same Formula)

Tirzepatide uses identical math. A 5mg vial with 1mL BAC water gives 5mg/mL. A 2.5mg titration dose = 50 units. A 5mg dose = 100 units. Increase the BAC water volume to lower the concentration and spread doses across more manageable unit marks.

Use the Interactive Calculator

For any vial size and any dose, the interactive reconstitution calculator handles the math instantly. It also supports Custom Draw mode — enter the unit mark you want to draw and it tells you how much BAC water to add to hit that exact mark.

→ Open Free Calculator at protocolapp.health

The same calculator is in the Protocol app — it saves your vial parameters, calculates remaining doses, and logs each injection automatically. Build your titration schedule alongside it.