Semaglutide & Tirzepatide Dose Calculator
Turn your prescribed dose into the units you draw up on a U-100 insulin syringe. This calculator works for two compounded formulas only: semaglutide 2.5 mg/mL and tirzepatide 10 mg/mL, each with niacinamide (vitamin B3) 2 mg/mL and cyanocobalamin (vitamin B12) 0.5 mg/mL.
1. Pick the medication on your vial label
Your label may list all three strengths together, like 2.5-2-0.5 mg/mL or 10-2-0.5 mg/mL. The first number is the GLP-1 strength, and it’s the one that sets your units. If it isn’t 2.5 or 10 mg/mL, this calculator doesn’t fit your vial.
2. Enter your dose
Draw up 10 units
- Volume
- 0.1 mL
- Semaglutide
- 0.25 mg
- Vitamin B3
- 0.2 mg
- Vitamin B12
- 50 mcg
Shown on a 1 mL (100-unit) syringe. Using a different size? Change it above.
Check your label first. If these units don’t match the units on your prescription label, don’t inject. Call the pharmacy that filled your prescription.
How the math works
Insulin syringes are marked in units. On a U-100 syringe, 100 units equals 1 mL, so each unit is 0.01 mL.
Units = dose in mg ÷ vial strength in mg/mL × 100
For example, 0.5 mg of semaglutide from a 2.5 mg/mL vial is 0.5 ÷ 2.5 = 0.2 mL, which is 20 units. 5 mg of tirzepatide from a 10 mg/mL vial is 5 ÷ 10 = 0.5 mL, which is 50 units.
Both formulas also contain niacinamide (vitamin B3) at 2 mg/mL and cyanocobalamin (vitamin B12) at 0.5 mg/mL. They don’t change your units; they come with each dose. Every 10 units (0.1 mL) has 0.2 mg of niacinamide and 50 mcg of cyanocobalamin.
Dose charts
| Dose | Volume | Units |
|---|---|---|
| 0.25 mg | 0.1 mL | 10 units |
| 0.5 mg | 0.2 mL | 20 units |
| 1 mg | 0.4 mL | 40 units |
| 1.5 mg | 0.6 mL | 60 units |
| 2 mg | 0.8 mL | 80 units |
| 2.5 mg | 1 mL | 100 units |
| Dose | Volume | Units |
|---|---|---|
| 2.5 mg | 0.25 mL | 25 units |
| 5 mg | 0.5 mL | 50 units |
| 7.5 mg | 0.75 mL | 75 units |
| 10 mg | 1 mL | 100 units |
| 12.5 mg | 1.25 mL | 125 units* |
| 15 mg | 1.5 mL | 150 units* |
* More than one 1 mL syringe holds, so these doses are split into two syringes: 75 + 50 units for 12.5 mg and 75 + 75 units for 15 mg. Inject both syringes. The charts list common doses, not a dosing schedule; your provider sets your dose.
Questions
What is a U-100 insulin syringe?
It’s the syringe marked in units: 100 units fills 1 mL. The 1 mL size holds 100 units and is usually marked every 2 units. The smaller 0.5 mL (50 units) and 0.3 mL (30 units) sizes are marked every unit.
How do I read the strengths on my label?
If your label lists three strengths together, like Semaglutide-Niacinamide-Cyanocobalamin 2.5-2-0.5 mg/mL, they follow the order of the ingredients: 2.5 mg/mL semaglutide, 2 mg/mL niacinamide (B3) and 0.5 mg/mL cyanocobalamin (B12). The first number is the GLP-1 strength, and it’s the one that sets your units.
Why do my units depend on my vial?
The same dose takes a different amount of liquid at a different strength. That’s why this calculator only works for semaglutide 2.5 mg/mL and tirzepatide 10 mg/mL. If your label shows any other GLP-1 strength, don’t use these numbers.
What if my dose falls between two lines?
Most 1 mL syringes are marked every 2 units, so an odd number of units, like 25 or 75, sits halfway between two lines. If you’re not sure how to measure it, ask your pharmacist to show you before you inject.
What if my dose is more than 100 units?
A 1 mL syringe holds 100 units, so a larger dose is split into two syringes. For 125 units, draw up 75 units in one syringe and 50 units in the other. For 150 units, draw up 75 units in each. Inject both syringes to get your full dose.
Do the B3 and B12 change my units?
No. Your units come from the GLP-1 strength alone. Both formulas have the same vitamin strengths, so every 10 units carries 0.2 mg of niacinamide (B3) and 50 mcg of cyanocobalamin (B12) along with your dose.
Are compounded semaglutide and tirzepatide FDA-approved?
No. Compounded medications are prepared by a licensed pharmacy for an individual patient’s prescription and are not FDA-approved.
This calculator is for education. It doesn’t replace your prescription label or your pharmacist’s instructions. Questions about your dose? Call the pharmacy that filled your prescription. Find your pharmacy · About GLP-1 treatment