ToolsDose math · Compounded vials
Tirzepatide Dose ↔ Unit Converter
mg ↔ units on a U-100 syringe, for compounded vials
Compounded tirzepatide comes in a multi-dose vial you reconstitute yourself and draw with an insulin syringe — so there is no fixed answer to “how many units?” until you know the vial’s concentration. This tool does that one piece of arithmetic: it takes the milligrams in the vial and the millilitres of bacteriostatic water you added to get a concentration in mg/mL, then converts a dose in milligrams to units (or units back to milligrams). It is a math converter, not a dose recommendation.
Read before you use this
This is a unit-conversion calculator only — not a dose recommendation and not medical advice. It does not tell you what dose to take, how to titrate, or whether compounded tirzepatide is appropriate for you. The FDA-approved brand products (Zepbound and Mounjaro) are fixed-dose pens and single-dose vials and are never measured in “units” — this converter applies only to compounded multi-dose vials drawn with an insulin syringe. Getting this conversion wrong has caused people to inject ten-fold overdoses. Confirm the result against your actual vial label and with your prescribing clinician and the compounding pharmacy before drawing or injecting anything. Tirzepatide is prescription-only.
Draw to
25units
That is 0.25 mL on a U-100 syringe, at a concentration of 10 mg/mL. Double-check against your vial and your clinician before drawing anything.
- Concentration
- 10
- mg / mL (vial ÷ BAC water)
- Volume to draw
- 0.25
- mL
- Units
- 25
- units (U-100)
How it is calculated. Concentration = vial total mg ÷ BAC water mL. On a U-100 insulin syringe, 100 units = 1 mL. For mg → units, units = (dose mg ÷ concentration) × 100; the reverse is mg = (units ÷ 100) × concentration. Worked example: a 10 mg vial reconstituted with 1 mL = 10 mg/mL; a 2.5 mg dose = 0.25 mL = 25 units.
Where to get it
Affiliate partners
Where compounded vials come from
Unit math only matters if you have a vial. These are the telehealth programs we partner with, each with clinician review of an online intake.
- Check availability
CoreAge Rx
Doctor-reviewed tirzepatide with one flat price and built-in human support.
$149/mo flatCompounded tirzepatide (503A)
- Check availability
Ageless
Broad compounded storefront pairing $169/month injectable tirzepatide with a rare oral-drop option — plus NAD+, sermorelin, and TRT under one roof.
$169/mo injectableCompounded tirzepatide (injectable and oral drops)
- Check availability
Found
Established, physician-designed weight care with a broad formulary — real brand-name Zepbound/Mounjaro alongside compounded tirzepatide, paired with coaching.
From $99/mo (varies)Broad formulary: compounded tirzepatide plus brand-name Zepbound/Mounjaro, brand/compounded semaglutide, and oral Rybelsus
See the full ranking, with prices plotted against the market median
Advertising disclosure. We may earn a commission if you start treatment through these links, at no extra cost to you. Full disclosure.
Understand the dosing math before you draw
The number is the easy part. Why “units” depend entirely on concentration, how brand dosing differs, and the real-world risks of compounded vials are the parts that matter — read these next:
This converter is informational and not medical advice. It performs simple arithmetic (concentration = vial mg ÷ BAC water mL; units = dose ÷ concentration × 100) and makes no judgment about what dose is safe or appropriate for you. Concentrations are not standardized across compounding pharmacies or even across vials, and an error here can cause a large overdose — always verify against your vial label and your prescribing clinician. Tirzepatide is available by prescription after clinician review.