GLP-1 Syringe Conversion Chart & Calculator
Complete conversion tables and interactive syringe calculator for compounded semaglutide and tirzepatide across every common vial concentration. Includes formulas, safety guidelines, and mL equivalents.
This is arithmetic, not a prescription. It converts a dose someone already prescribed you into syringe units. It does not tell you what dose to take, and it cannot know what is in your vial. Read the concentration off the vial in your hand every single time — not the last one, not the one in the photo on the pharmacy's website.
How do you convert milligrams (mg) to insulin syringe units? Syringe units measure liquid volume, not active drug weight (100 units = 1.0 mL). Use the two standard clinical formulas:
- Forward Formula (mg → Units):
Syringe Units = (Prescribed Dose in mg ÷ Vial Concentration in mg/mL) × 100 - Reverse Formula (Units → mg):
Delivered Dose in mg = (Syringe Units Drawn ÷ 100) × Vial Concentration in mg/mL - Key Syringe Mark Rules (U-100): 10 units = 0.1 mL | 12.5 units = 0.125 mL | 25 units = 0.25 mL | 50 units = 0.5 mL | 100 units = 1.0 mL.
Quick Reference Benchmarks: 0.25 mg Semaglutide is 5 units (from 5 mg/mL) or 10 units (from 2.5 mg/mL). 2.5 mg Tirzepatide is 12.5 units (from 20 mg/mL) or 25 units (from 10 mg/mL). 10 units delivers 0.5 mg from a 5 mg/mL vial. Always confirm the concentration printed on your specific vial before drawing.
Universal Syringe Conversion Calculator
Select your medication, click a preset dose or enter your vial numbers to calculate your exact syringe draw line.
Semaglutide Syringe Conversion Matrix (U-100 Syringe)
Dosing chart for compounded semaglutide (Ozempic/Wegovy active ingredient). Units represent volume on a standard 100-unit (1.0 mL) insulin syringe.
| Prescribed Dose | 1 mg/mL | 2 mg/mL | 2.5 mg/mL | 4 mg/mL | 5 mg/mL (Standard) | 10 mg/mL | Titration Phase | Answer Guide |
|---|---|---|---|---|---|---|---|---|
| 0.1 mg | 10 u | 5 u | 4 u | 2.5 u | 2 u | 1 u | Microdose evaluation | Full chart → |
| 0.25 mg | 25 u | 12.5 u | 10 u | 6.25 u | 5 u | 2.5 u | Starting adaptation dose (Wks 1-4) | Full chart → |
| 0.5 mg | 50 u | 25 u | 20 u | 12.5 u | 10 u | 5 u | Therapeutic step 1 (Wks 5-8) | Full chart → |
| 1 mg | 100 u | 50 u | 40 u | 25 u | 20 u | 10 u | Therapeutic step 2 (Wks 9-12) | Full chart → |
| 1.25 mg | >100 u | 62.5 u | 50 u | 31.25 u | 25 u | 12.5 u | Intermediate plateau breaker | Full chart → |
| 1.5 mg | >100 u | 75 u | 60 u | 37.5 u | 30 u | 15 u | Intermediate plateau breaker | Full chart → |
| 1.7 mg | >100 u | 85 u | 68 u | 42.5 u | 34 u | 17 u | Pre-maintenance (Wks 13-16) | Full chart → |
| 1.75 mg | >100 u | 87.5 u | 70 u | 43.75 u | 35 u | 17.5 u | Intermediate plateau breaker | Full chart → |
| 2 mg | >100 u | 100 u | 80 u | 50 u | 40 u | 20 u | Max Ozempic diabetes dose | Full chart → |
| 2.4 mg | >100 u | >100 u | 96 u | 60 u | 48 u | 24 u | Top Wegovy maintenance (Wks 17+) | Full chart → |
* Green column highlights 5 mg/mL, the most common standard concentration provided by 503A compounding pharmacies. Red flag (>100 u) indicates the volume exceeds a single 1 mL syringe.
Tirzepatide Syringe Conversion Matrix (U-100 Syringe)
Dosing chart for compounded tirzepatide (Mounjaro/Zepbound active ingredient). Tirzepatide formulations are significantly more concentrated than semaglutide.
| Prescribed Dose | 5 mg/mL | 10 mg/mL | 15 mg/mL | 20 mg/mL (Standard) | 25 mg/mL | 50 mg/mL | Titration Phase | Answer Guide |
|---|---|---|---|---|---|---|---|---|
| 1.25 mg | 25 u | 12.5 u | 8.333 u | 6.25 u | 5 u | 2.5 u | Split-dose start | Full chart → |
| 2.5 mg | 50 u | 25 u | 16.667 u | 12.5 u | 10 u | 5 u | Standard initiation (Wks 1-4) | Full chart → |
| 5 mg | 100 u | 50 u | 33.333 u | 25 u | 20 u | 10 u | Maintenance tier 1 (Wk 5+) | Full chart → |
| 7.5 mg | >100 u | 75 u | 50 u | 37.5 u | 30 u | 15 u | Titration step (Wk 9+) | Full chart → |
| 10 mg | >100 u | 100 u | 66.667 u | 50 u | 40 u | 20 u | Maintenance tier 2 (Wk 13+) | Full chart → |
| 12.5 mg | >100 u | >100 u | 83.333 u | 62.5 u | 50 u | 25 u | Titration step (Wk 17+) | Full chart → |
| 15 mg | >100 u | >100 u | 100 u | 75 u | 60 u | 30 u | Max approved dose (Wk 21+) | Full chart → |
* Green column highlights 20 mg/mL, the most widely dispensed tirzepatide concentration. Red flag (>100 u) indicates volume exceeds standard 1 mL syringe.
Reverse Chart: Syringe Units to Milligrams
If you have drawn a specific number of units and want to verify the exact milligram dose you are administering, use this reverse conversion table:
| Units Drawn | Volume (mL) | Sema (2.5 mg/mL) | Sema (5.0 mg/mL) | Tirz (10 mg/mL) | Tirz (20 mg/mL) | Clinical Context | Answers |
|---|---|---|---|---|---|---|---|
| 5 units | 0.05 mL | 0.125 mg | 0.25 mg | 0.5 mg | 1 mg | 0.25 mg sema at 5 mg/mL or 1.0 mg tirz at 20 mg/mL | Sema · Tirz |
| 10 units | 0.1 mL | 0.25 mg | 0.5 mg | 1 mg | 2 mg | 0.25 mg sema at 2.5 mg/mL or 0.5 mg sema at 5 mg/mL (or 2 mg tirz at 20 mg/mL) | Sema · Tirz |
| 12.5 units | 0.125 mL | 0.312 mg | 0.625 mg | 1.25 mg | 2.5 mg | 2.5 mg tirz at 20 mg/mL (Standard starting dose) | Sema · Tirz |
| 15 units | 0.15 mL | 0.375 mg | 0.75 mg | 1.5 mg | 3 mg | 0.75 mg sema at 5 mg/mL | Sema · Tirz |
| 20 units | 0.2 mL | 0.5 mg | 1 mg | 2 mg | 4 mg | 0.5 mg sema at 2.5 mg/mL or 1.0 mg sema at 5 mg/mL | Sema · Tirz |
| 25 units | 0.25 mL | 0.625 mg | 1.25 mg | 2.5 mg | 5 mg | 2.5 mg tirz at 10 mg/mL or 1.25 mg sema at 5 mg/mL | Sema · Tirz |
| 30 units | 0.3 mL | 0.75 mg | 1.5 mg | 3 mg | 6 mg | 1.5 mg sema at 5 mg/mL | Sema · Tirz |
| 35 units | 0.35 mL | 0.875 mg | 1.75 mg | 3.5 mg | 7 mg | 1.75 mg sema at 5 mg/mL | Sema · Tirz |
| 37.5 units | 0.375 mL | 0.938 mg | 1.875 mg | 3.75 mg | 7.5 mg | 1.875 mg sema at 5 mg/mL | Sema · Tirz |
| 40 units | 0.4 mL | 1 mg | 2 mg | 4 mg | 8 mg | 1.0 mg sema at 2.5 mg/mL or 2.0 mg sema at 5 mg/mL | Sema · Tirz |
| 50 units | 0.5 mL | 1.25 mg | 2.5 mg | 5 mg | 10 mg | 5.0 mg tirz at 10 mg/mL or 2.5 mg sema at 5 mg/mL | Sema · Tirz |
| 60 units | 0.6 mL | 1.5 mg | 3 mg | 6 mg | 12 mg | 3 mg sema at 5 mg/mL | Sema · Tirz |
| 75 units | 0.75 mL | 1.875 mg | 3.75 mg | 7.5 mg | 15 mg | 7.5 mg tirz at 10 mg/mL or 15 mg tirz at 20 mg/mL | Sema · Tirz |
| 100 units | 1 mL | 2.5 mg | 5 mg | 10 mg | 20 mg | Full 1 mL syringe: 5 mg sema (5 mg/mL) or 20 mg tirz (20 mg/mL) | Sema · Tirz |
Milliliters (mL) to Insulin Syringe Units
Patients frequently receive prescription paperwork in millilitres (mL) while insulin syringes are calibrated in units. On a standard U-100 syringe, 1.0 mL = 100 units:
| Liquid Volume (mL) | Units on U-100 Syringe | Proportion of Barrel | Clinical Application Example |
|---|---|---|---|
| 0.05 mL | 5 units | 1/20th syringe | 0.25 mg semaglutide from 5 mg/mL vial |
| 0.10 mL | 10 units | 1/10th syringe | 0.50 mg semaglutide from 5 mg/mL vial (or 0.25 mg from 2.5 mg/mL) |
| 0.125 mL | 12.5 units | Halfway between 12 & 13 units | 2.5 mg tirzepatide from standard 20 mg/mL vial |
| 0.20 mL | 20 units | 1/5th syringe | 1.0 mg semaglutide from 5 mg/mL vial |
| 0.25 mL | 25 units | 1/4th syringe | 2.5 mg tirzepatide from 10 mg/mL vial |
| 0.30 mL | 30 units | 3/10th syringe | 1.5 mg semaglutide from 5 mg/mL vial |
| 0.375 mL | 37.5 units | Halfway between 37 & 38 units | 7.5 mg tirzepatide from 20 mg/mL vial |
| 0.50 mL | 50 units | 1/2 syringe (half barrel) | 5.0 mg tirzepatide from 10 mg/mL vial (or 2.5 mg sema from 5 mg/mL) |
| 0.75 mL | 75 units | 3/4th syringe | 7.5 mg tirzepatide from 10 mg/mL vial (or 15 mg from 20 mg/mL) |
| 1.00 mL | 100 units | Full syringe capacity | Full 1.0 mL capacity of standard U-100 syringe |
All Individual Dose Answer Pages
Milligrams to syringe units
Your prescriber gave you a dose in mg. These convert it to units on a U-100 insulin syringe.
- 0.1 mg of semaglutide in units
- 0.25 mg of semaglutide in units
- 0.5 mg of semaglutide in units
- 1 mg of semaglutide in units
- 1.25 mg of semaglutide in units
- 1.5 mg of semaglutide in units
- 1.7 mg of semaglutide in units
- 1.75 mg of semaglutide in units
- 2 mg of semaglutide in units
- 2.4 mg of semaglutide in units
- 1.25 mg of tirzepatide in units
- 2.5 mg of tirzepatide in units
- 5 mg of tirzepatide in units
- 7.5 mg of tirzepatide in units
- 10 mg of tirzepatide in units
- 12.5 mg of tirzepatide in units
- 15 mg of tirzepatide in units
Syringe units to milligrams
You have drawn a number of units and want to know what dose that actually is.
- 5 units of semaglutide in mg
- 8 units of semaglutide in mg
- 10 units of semaglutide in mg
- 12.5 units of semaglutide in mg
- 15 units of semaglutide in mg
- 16 units of semaglutide in mg
- 20 units of semaglutide in mg
- 24 units of semaglutide in mg
- 25 units of semaglutide in mg
- 30 units of semaglutide in mg
- 35 units of semaglutide in mg
- 37.5 units of semaglutide in mg
- 40 units of semaglutide in mg
- 45 units of semaglutide in mg
- 50 units of semaglutide in mg
- 60 units of semaglutide in mg
- 70 units of semaglutide in mg
- 75 units of semaglutide in mg
- 80 units of semaglutide in mg
- 90 units of semaglutide in mg
- 100 units of semaglutide in mg
- 5 units of tirzepatide in mg
- 8 units of tirzepatide in mg
- 10 units of tirzepatide in mg
- 12.5 units of tirzepatide in mg
- 15 units of tirzepatide in mg
- 16 units of tirzepatide in mg
- 20 units of tirzepatide in mg
- 24 units of tirzepatide in mg
- 25 units of tirzepatide in mg
- 30 units of tirzepatide in mg
- 35 units of tirzepatide in mg
- 37.5 units of tirzepatide in mg
- 40 units of tirzepatide in mg
- 45 units of tirzepatide in mg
- 50 units of tirzepatide in mg
- 60 units of tirzepatide in mg
- 70 units of tirzepatide in mg
- 75 units of tirzepatide in mg
- 80 units of tirzepatide in mg
- 90 units of tirzepatide in mg
- 100 units of tirzepatide in mg
The mistake that sends people to hospital
In July 2024 the FDA alerted providers and patients that people using compounded injectable semaglutide had administered five to twenty times the intended dose. The cause was not recklessness. It was that milligrams, millilitres and insulin syringe units are three different quantities, and a vial label only tells you one of them.
Here is the whole trap in one line: a 5 mg vial reconstituted into 1 mL and a 5 mg vial reconstituted into 2 mL carry the same number on the label and need completely different syringe volumes for an identical prescribed dose. One is 5 mg/mL, the other is 2.5 mg/mL. Draw the same units from both and one of them is double.
Two habits prevent nearly all of it. Confirm the concentration on the specific vial before every draw, and re-check the number when you change pharmacy, batch or refill — concentrations are not standardised between compounders and can change without anything on the outside of the box looking different.
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Frequently Asked Questions
- How many units is 0.25 mg of semaglutide on a U-100 insulin syringe?
- It depends on your vial concentration. At the most common concentration of 5 mg/mL, 0.25 mg is 5 units. At 2.5 mg/mL, it is 10 units. At 2 mg/mL, it is 12.5 units. At 1 mg/mL, it is 25 units. Always confirm the concentration printed on your prescription label before drawing.
- How many units is 0.5 mg of semaglutide?
- At 5 mg/mL, 0.5 mg equals 10 units. At 2.5 mg/mL, it equals 20 units. At 2 mg/mL, it equals 25 units. At 1 mg/mL, it equals 50 units on a U-100 syringe.
- How many units is 1.0 mg of semaglutide?
- At 5 mg/mL, 1.0 mg is 20 units. At 2.5 mg/mL, it is 40 units. At 2 mg/mL, it is 50 units.
- How many units is 1.5 mg of semaglutide?
- At 5 mg/mL, 1.5 mg is 30 units. At 2.5 mg/mL, it is 60 units. At 4 mg/mL, it is 37.5 units.
- How many units is 2.5 mg of tirzepatide on an insulin syringe?
- At the standard concentration of 20 mg/mL, 2.5 mg tirzepatide equals 12.5 units (0.125 mL). At 10 mg/mL, it equals 25 units (0.25 mL). At 5 mg/mL, it equals 50 units.
- How many units is 5 mg of tirzepatide?
- At 20 mg/mL, 5 mg tirzepatide equals 25 units. At 10 mg/mL, it equals 50 units (half of a 1 mL syringe).
- How many units is 12.5 mg of tirzepatide?
- At 20 mg/mL, 12.5 mg is 62.5 units. At 25 mg/mL, it is 50 units.
- How many mg is 10 units on an insulin syringe?
- On a U-100 syringe, 10 units is always 0.1 mL. If your vial is 5 mg/mL semaglutide, 10 units delivers 0.5 mg. If your vial is 2.5 mg/mL, 10 units delivers 0.25 mg. If your vial is 20 mg/mL tirzepatide, 10 units delivers 2.0 mg.
- How many mg is 12.5 units of tirzepatide?
- At the standard 20 mg/mL concentration, 12.5 units contains exactly 2.5 mg of tirzepatide (the standard starting dose). On a syringe, 12.5 units is 0.125 mL.
- How many insulin units is 0.125 mL?
- On a standard U-100 insulin syringe, 1 mL equals 100 units. Therefore, 0.125 mL equals exactly 12.5 units (0.125 × 100 = 12.5 units).
- What is the mathematical formula to convert mg to syringe units?
- The formula is:
Syringe Units = (Prescribed Dose in mg ÷ Vial Concentration in mg/mL) × 100. To find your vial concentration, divide the total mg listed on the vial by the total mL of liquid after reconstitution.
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