Weight loss tools
Your dose in mg. Your draw in units.
Pick your medication, your pharmacy and the label on your vial. The calculator tells you how many units to draw on your syringe. Works for compounded tirzepatide and semaglutide from any pharmacy.
Written by the Belle clinical teamMedically reviewed by Patrick Taylor, MD
What do you want to do?
Which medication?
Which pharmacy is your medicine from?
Which label matches your vial?
Pick your pharmacy first.
What is your dose?
Units charts by medication
How to read your vial label
Pharmacies print strengths in different ways. These are the label formats that cause the most mix-ups, and what each one means.
Strength printed per half mL
Tirzepatide 10 mg / 0.5 mL
The strength is per half a milliliter, so the real concentration is double the printed number: 20 mg/mL.
An additive that looks like a volume
Tirzepatide 30 mg / 0.5 mg / mL
That's 30 mg/mL of tirzepatide plus 0.5 mg/mL of an additive such as B12 or glycine, not 30 mg per half mL.
The additive is listed first
Niacinamide / Tirzepatide 2 mg / 17.65 mg / mL
The ingredient names set the order of the numbers, so tirzepatide is 17.65 mg/mL, not the first number.
An additive bigger than the drug
Tirzepatide / Pyridoxine 10 mg / 25 mg / mL
The biggest number isn't always the medication; here tirzepatide is 10 mg/mL and the additive is 25 mg/mL.
Three-part labels
Tirzepatide / Glycine / B12 10 mg / 5 mg / 500 mcg / mL
Match each number to its ingredient in order; only the first, 10 mg/mL, is tirzepatide.
Vial totals next to the strength
Tirzepatide 72 mg / 4 mL (18 mg/mL)
The total in the vial is 72 mg across 4 mL; the number that matters for your draw is the per-mL strength, 18 mg/mL.
A strength with no "/mL"
Tirzepatide 18 mg, 4 mL vial
Some labels print only the strength and the vial size. It may be 18 mg per mL (72 mg in the vial), or 18 mg in the whole vial. Check your prescription or message your care team.
Dashes that look like ranges
Tirzepatide / Glycine 8-5 mg/mL (2.5 mL) (20 mg)
The dash separates two ingredients, it isn't a range: tirzepatide is 8 mg/mL, which across 2.5 mL gives the 20 mg total.
Common questions
How do I convert mg to units?
Divide your dose in mg by your vial's mg per mL, multiply by 100, and round down. For example, 2.5 mg at 20 mg/mL: 2.5 ÷ 20 × 100 = 12.5, so 12 units.
What is a unit on an insulin syringe?
A unit is 1/100 of a mL. On most 1 mL syringes, each small line is 2 units, so count the lines carefully and check where your dose lands.
Which syringe should I use?
A standard 100-unit (1 mL) insulin syringe, which is what the calculator uses. If your dose is more than 100 units, the calculator shows how to split it across two syringes.
For educational purposes only. Always follow the dose and instructions your provider gave you. Compounded medications are not evaluated or approved by the FDA.