GLP1 MathFrequently asked questions
Questions
How many units is 0.25 mg of semaglutide?
It depends on your vial strength. At 2.5 mg per mL, 0.25 mg is 0.1 mL, which is 10 units on a U-100 insulin syringe. At 5 mg per mL it is 5 units. Use the calculator with the strength printed on your vial.
What does 'units' mean on a syringe?
On a U-100 insulin syringe, 100 units equals 1 mL, so each unit is 0.01 mL. Units measure liquid volume on the syringe, not the amount of medicine. The amount of medicine depends on the vial strength.
Why do two people on the same dose draw different units?
Because compounded vials come in different strengths. The same 0.5 mg dose is 20 units from a 2.5 mg/mL vial and 10 units from a 5 mg/mL vial.
Does this work for Ozempic or Wegovy pens?
No. Brand pens are pre-measured and you dial the dose in mg. This calculator is for vials drawn with an insulin syringe, which is how most compounded semaglutide is supplied.
How many units is 2.5 mg of tirzepatide?
At 10 mg per mL, 2.5 mg is 0.25 mL, which is 25 units on a U-100 insulin syringe. At 20 mg per mL it is 12.5 units. Use the strength printed on your vial.
Why are tirzepatide doses bigger numbers than semaglutide?
They are different medicines with different dose ranges. Tirzepatide doses are typically 2.5 to 15 mg per week, while semaglutide doses are typically 0.25 to 2.4 mg per week.
Can I use this for Zepbound or Mounjaro pens?
Brand pens are single-dose and pre-measured, so no conversion is needed. Zepbound single-dose vials and compounded vials are drawn with a syringe, which is what this calculator is for.
How do I figure out my real yearly cost?
Multiply what you pay per fill by how many fills you need in a year. Four-week pens and vials mean 13 fills a year, not 12. Add any program fees, visits or supplies you pay separately.
Why does the calculator use 13 fills a year?
Weekly medicines are usually dispensed in 4-week supplies. 52 weeks divided by 4 is 13, so paying 'per month' for a 4-week supply quietly adds one extra fill each year.
Does insurance cover GLP-1 medicines?
Coverage varies by plan and by whether the medicine is prescribed for diabetes or for weight. Call your insurer or check your plan's drug list with the exact product name.
How long does it take to reach a maintenance dose?
On the standard labeled schedules, Wegovy reaches 2.4 mg at week 17 and Zepbound can reach 15 mg by week 21 if each step is tolerated. Prescribers often hold a dose longer, which is normal.
Can I move up faster?
Follow your prescriber. The labeled schedules use at least four weeks per step to help with side effects such as nausea.
What if my doctor gave me a different schedule?
Use theirs. This tool shows the standard labeled steps so you can see dates on a calendar; your prescriber's plan always comes first.