How do I convert mg to units for semaglutide or tirzepatide?

Divide your dose in mg by your vial's concentration in mg/mL to get mL, then multiply by 100 to get units on a U-100 insulin syringe. Example: 2.5 mg from a 10 mg/mL vial is 0.25 mL, which is 25 units.

How many units is 0.25 mg of semaglutide?

It depends on your vial's concentration. At 2.5 mg/mL, 0.25 mg is 10 units. At 5 mg/mL, it is 5 units. Always check the concentration printed on your pharmacy label.

How many units is 2.5 mg of tirzepatide?

At 10 mg/mL, 2.5 mg is 25 units. At 20 mg/mL, it is 12.5 units. At 30 mg/mL, it is about 8.3 units. Always check the concentration printed on your pharmacy label.

Free tool

GLP-1 mg to units calculator

Q: Does this work for Ozempic, Wegovy, Mounjaro, or Zepbound pens?

No. Brand-name pens are dosed by clicking to a set mg dose, not drawn in units. This calculator is for vials drawn with a U-100 insulin syringe, which is how most compounded medication is dispensed.

For compounded semaglutide or tirzepatide drawn with a U-100 insulin syringe. No sign-up.

Enter your dose and concentration to see how many units to draw.

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How the conversion works

Most compounded GLP-1s come in a vial you draw with a U-100 insulin syringe. On those syringes, 100 units = 1 mL. So:

units = (dose in mg ÷ concentration in mg/mL) × 100

Example: a 2.5 mg dose from a 10 mg/mL vial is 2.5 ÷ 10 = 0.25 mL, which is 25 units.

If you mixed the vial yourself, concentration is the mg in the vial divided by the mL of water you added. A 10 mg vial with 1 mL of water is 10 mg/mL; with 2 mL it's 5 mg/mL.

Quick reference

Compounded semaglutide

Dose	2.5 mg/mL	5 mg/mL
0.25 mg	10 units	5 units
0.5 mg	20 units	10 units
1 mg	40 units	20 units
1.7 mg	68 units	34 units
2.4 mg	96 units	48 units

Compounded tirzepatide

Dose	10 mg/mL	20 mg/mL	30 mg/mL
2.5 mg	25 units	12.5 units	8.3 units
5 mg	50 units	25 units	16.7 units
7.5 mg	75 units	37.5 units	25 units
10 mg	100 units	50 units	33.3 units
12.5 mg	125 units*	62.5 units	41.7 units
15 mg	150 units*	75 units	50 units

Common questions

Does this work for Ozempic, Wegovy, Mounjaro, or Zepbound pens?

No. Brand-name pens click to a set mg dose, and you never draw units. This is for vials and insulin syringes.

Why is my number a decimal like 12.5 units?

0.3 mL and 0.5 mL syringes are usually marked every 1 unit (some every half unit), and 1 mL syringes every 2 units. If your dose falls between lines, a smaller syringe makes it easier to read. Ask your pharmacy how to round.

My pharmacy label says something different.

Follow the pharmacy. Their label is specific to the medication they made for you. Call them if the numbers don't agree.

What if my label only lists mg per vial?

Use the "I mixed the vial" tab, or divide the total mg by the total mL in the vial to get mg/mL.

When is your next dose increase? Plan it with the dose schedule planner →

How much is in your system right now? Try the medication level estimator →

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