Convert your prescribed compounded GLP-1 dose from milligrams to units on a U-100 insulin syringe. Works for semaglutide, tirzepatide and any vial concentration. ⚕️ Educational
mg → syringe units
⚕️ Educational tool only — not medical advice. Always follow the exact dosing instructions from your prescriber and pharmacist.
Compounded semaglutide and tirzepatide are dosed in milligrams, but you draw them with a U-100 insulin syringe marked in units. The conversion is simple: units = (dose in mg ÷ concentration in mg/mL) × 100, and the injected volume is dose ÷ concentration in mL. For example, a 0.25 mg dose from a 5 mg/mL vial is 0.05 mL = 5 units.
On a U-100 syringe, 100 units equals 1 mL, so each unit mark is 0.01 mL. Always double-check the concentration on your specific vial — concentrations vary between pharmacies, so the same dose can mean a different number of units. This is an educational converter, not medical advice; follow your prescriber's and pharmacist's instructions.
GLP-1 receptor agonists are dosed in milligrams according to a manufacturer-specified schedule rather than by body weight, which distinguishes them from most weight-related medicines. Because the pens deliver a fixed volume at a given concentration, converting between the prescribed dose in milligrams and the units or volume shown on a device is a common source of confusion — and an error here is a dosing error, not a rounding issue. The escalation schedule exists to manage gastrointestinal side effects, which are the main reason people discontinue.
Volume (mL) = Dose (mg) ÷ Concentration (mg/mL)Units on a U-100 style scale = mL × 100Weekly dose is fixed by the prescribed schedule, not by body weightwhere:
Assumptions: General information only, not medical advice or a prescribing tool. Always follow the prescription and the product labelling. Never adjust a dose without clinical direction, and never use a device with an unfamiliar concentration without confirming it.
Convert a prescribed dose into the volume a pen must deliver at two concentrations.
Result1.0 mg = 0.50 mL at 2 mg/mL, but only 0.125 mL at 8 mg/mL
The fourfold difference between concentrations is exactly why volume must be recomputed whenever a product or strength changes. Carrying a remembered "number of units" from one pen to another is the specific error this calculation exists to prevent.
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