GLP-1 Dose Calculator
Turn your compounded semaglutide or tirzepatide vial into the exact units to draw on an insulin syringe. Enter your vial strength, solution volume and prescribed dose - the maths runs in your browser.
FDA titration schedules (reference)
Standard label escalation. Your prescriber sets your actual schedule - use this only to read the maths, not to change your plan.
Semaglutide (Wegovy)
| Weeks | Weekly dose | Phase |
|---|---|---|
| 1-4 | 0.25 mg | Initiation |
| 5-8 | 0.5 mg | Escalation |
| 9-12 | 1 mg | Escalation |
| 13-16 | 1.7 mg | Escalation |
| 17+ | 2.4 mg | Maintenance |
Tirzepatide (Zepbound / Mounjaro)
| Weeks | Weekly dose | Phase |
|---|---|---|
| 1-4 | 2.5 mg | Initiation |
| 5-8 | 5 mg | Escalation |
| 9-12 | 7.5 mg | Escalation |
| 13-16 | 10 mg | Escalation |
| 17-20 | 12.5 mg | Escalation |
| 21+ | 15 mg | Maintenance |
GLP-1 is dosed weekly. Enter your last injection date to see when the next one is due.
How GLP-1 dosing maths works
Compounded semaglutide and tirzepatide come in vials of differing strengths, so the same prescribed dose can be a different number of units depending on the vial. The calculator works it out in three steps. First it finds the concentration - the vial's total milligrams divided by the solution volume, giving milligrams per millilitre. Then it divides your prescribed dose by that concentration to get the millilitres to draw. Finally it converts millilitres to units: on a U-100 insulin syringe 1 mL is 100 units, so it multiplies the millilitres by 100. A U-40 syringe reads 40 units per millilitre instead.
Reading your vial label matters more than the brand name. If the label shows a concentration such as 10 mg/mL, enter the vial's total milligrams and its total volume so the same concentration comes out. If your draw lands between the unit marks, most people draw to the nearest mark and confirm the technique with their prescriber or pharmacist.
GLP-1 calculator FAQ
My vial label only shows mg/mL - what do I enter?
Enter the vial's total milligrams as the strength and the total millilitres as the solution volume. A 10 mg/mL vial holding 2 mL is 20 mg and 2 mL - the calculator derives the same 10 mg/mL concentration.
Do I use a U-100 or U-40 syringe?
Most compounded GLP-1 is drawn with a U-100 insulin syringe, where 1 mL equals 100 units. Check the markings on your own syringe and pick the matching option, because the unit result depends on it.
What if the units come out as a decimal?
Small decimals are normal at low doses. Draw as close to the mark as you can and confirm the technique with your prescriber or pharmacist - do not change your prescribed dose to make the number rounder.
Are the titration schedules a dose recommendation?
No. The tables show the standard FDA label escalation for reference only. Your prescriber sets your actual schedule.