GLP-1 Dose Calculator
Semaglutide & Tirzepatide — mg to mL & Syringe Units
By KAMP Inc. / UnitOwl · Last reviewed:
How GLP-1 Dose Conversion Works
GLP-1 medications like semaglutide and tirzepatide are prescribed in milligrams (mg). When drawing a dose into a U-100 insulin syringe, you work in syringe units — the markings on the barrel. The conversion involves two steps:
- mg → mL: Divide your prescribed dose (mg) by your vial's concentration (mg/mL). This gives you the volume to draw.
- mL → units: Multiply the volume (mL) by 100. A U-100 syringe has 100 unit-marks per mL, so this converts mL directly to syringe units.
Formula
Volume (mL) = Dose (mg) ÷ Concentration (mg/mL)
Syringe Units (U-100) = Volume (mL) × 100
Example: 0.5 mg dose ÷ 2.5 mg/mL = 0.20 mL = 20 units
The vial concentration is printed on the label in mg/mL. It varies by formulation, so always verify before drawing. Entering the wrong concentration produces the wrong unit count.
Semaglutide Dose Conversion Reference
Pre-calculated conversions for common semaglutide doses. Find your vial concentration in the table header — the values show the mL volume and U-100 syringe units for each dose.
| Dose (mg) | 0.5 mg/mL | 1 mg/mL | 2 mg/mL | 2.5 mg/mL |
|---|---|---|---|---|
| 0.25 mg | 0.50 mL (50u) | 0.25 mL (25u) | 0.13 mL (13u) | 0.10 mL (10u) |
| 0.5 mg | 1.00 mL (100u) | 0.50 mL (50u) | 0.25 mL (25u) | 0.20 mL (20u) |
| 1 mg | 2.00 mL (200u) | 1.00 mL (100u) | 0.50 mL (50u) | 0.40 mL (40u) |
| 1.7 mg | 3.40 mL (340u) | 1.70 mL (170u) | 0.85 mL (85u) | 0.68 mL (68u) |
| 2 mg | 4.00 mL (400u) | 2.00 mL (200u) | 1.00 mL (100u) | 0.80 mL (80u) |
| 2.4 mg | 4.80 mL (480u) | 2.40 mL (240u) | 1.20 mL (120u) | 0.96 mL (96u) |
u = units on a U-100 insulin syringe. Values rounded to nearest unit. Verify with your pharmacist.
Tirzepatide Dose Conversion Reference
Pre-calculated conversions for the full tirzepatide dosing range. Tirzepatide is titrated from 2.5 mg up to 15 mg over several months as directed by your provider.
| Dose (mg) | 2.5 mg/mL | 5 mg/mL | 10 mg/mL |
|---|---|---|---|
| 2.5 mg | 1.00 mL (100u) | 0.50 mL (50u) | 0.25 mL (25u) |
| 5 mg | 2.00 mL (200u) | 1.00 mL (100u) | 0.50 mL (50u) |
| 7.5 mg | 3.00 mL (300u) | 1.50 mL (150u) | 0.75 mL (75u) |
| 10 mg | 4.00 mL (400u) | 2.00 mL (200u) | 1.00 mL (100u) |
| 12.5 mg | 5.00 mL (500u) | 2.50 mL (250u) | 1.25 mL (125u) |
| 15 mg | 6.00 mL (600u) | 3.00 mL (300u) | 1.50 mL (150u) |
u = units on a U-100 insulin syringe. Verify your vial concentration with your pharmacist.
Reading a U-100 Syringe
U-100 insulin syringes are calibrated for solutions at 100 units per mL. The unit markings on the barrel are a volume scale — each unit equals exactly 0.01 mL. When drawing a GLP-1 medication into a U-100 syringe, "units" simply tells you how far to pull the plunger; it does not describe a dose of the medication itself.
- Each 1 unit mark = 0.01 mL
- 10 units = 0.10 mL
- 25 units = 0.25 mL
- 50 units = 0.50 mL
- 100 units = 1.00 mL (full 1 mL syringe)
Common U-100 syringe capacities are 0.3 mL (30 units), 0.5 mL (50 units), and 1.0 mL (100 units). Smaller-capacity syringes have finer graduation marks between units, which can make it easier to draw small volumes accurately. Your provider or pharmacist can recommend the appropriate syringe size for your dose.
About GLP-1 Medications
GLP-1 receptor agonists (glucagon-like peptide-1) are a class of prescription medications that mimic a naturally occurring hormone. They work by stimulating insulin secretion in response to meals, suppressing glucagon, slowing gastric emptying, and reducing appetite. The two most widely prescribed injectable GLP-1 medications are:
- Semaglutide — a GLP-1 receptor agonist. FDA-approved for type 2 diabetes management (Ozempic®) and chronic weight management (Wegovy®). Once-weekly subcutaneous injection.
- Tirzepatide — a dual GIP and GLP-1 receptor agonist. FDA-approved for type 2 diabetes (Mounjaro®) and obesity (Zepbound®). Once-weekly subcutaneous injection.
Both medications are available by prescription only. This calculator converts the dose your provider prescribed — it does not recommend doses or suggest what medication to take.
Safety Notes
Verify the vial concentration before every injection
The concentration (mg/mL) on the vial label is essential to this calculation. Using the wrong value — even by a small amount — will result in drawing an incorrect dose. Read the label each time you prepare an injection, and contact your pharmacy if the label is unclear.
Confirm with your provider or pharmacist
This calculator converts a dose you enter. It does not account for your medical history, kidney function, body weight, or titration schedule. If a calculated volume looks unexpected — too large or too small for your syringe — call your pharmacy or provider before injecting.
Storage and handling
GLP-1 medications in vials are typically refrigerated at 36–46°F (2–8°C). Check your specific medication's dispensing label and prescribing information for storage temperature and discard-after-opening guidance. Do not use medication that appears cloudy, discolored, or contains particles — contact your pharmacy.
Subcutaneous injection basics
GLP-1 medications are administered as subcutaneous (under-the-skin) injections. Common sites include the abdomen, outer thigh, and upper arm. Rotate injection sites to prevent tissue buildup at any one location. Use a new needle for each injection. If you are new to self-injection, ask your provider or pharmacist to walk you through the technique at your first visit.
Frequently Asked Questions
How do I convert a semaglutide mg dose to syringe units?
Divide your prescribed dose (mg) by the vial concentration (mg/mL), then multiply by 100. For example, a 0.5 mg dose from a 1 mg/mL vial: (0.5 ÷ 1) × 100 = 50 units on a U-100 syringe. A 0.5 mg dose from a 2 mg/mL vial: (0.5 ÷ 2) × 100 = 25 units. The vial concentration is printed on the label — it determines the final unit count.
What is 0.5 mg of semaglutide in units?
It depends on your vial concentration. At 0.5 mg/mL: 100 units. At 1 mg/mL: 50 units. At 2 mg/mL: 25 units. At 2.5 mg/mL: 20 units. At 5 mg/mL: 10 units. Check the label on your specific vial and enter the concentration into the calculator above to get the exact result for your dose.
How do I convert tirzepatide mg to units?
The same formula applies: Units = (Dose mg ÷ Concentration mg/mL) × 100. For a 2.5 mg dose from a 5 mg/mL vial: (2.5 ÷ 5) × 100 = 50 units. For a 5 mg dose from the same vial: (5 ÷ 5) × 100 = 100 units. Select Tirzepatide in the calculator, enter your dose and vial concentration, and the result is instant.
What does U-100 mean on an insulin syringe?
U-100 means the syringe is calibrated for solutions with 100 units per mL. Each unit mark on the syringe equals 0.01 mL. When drawing a GLP-1 medication into a U-100 syringe, the unit markings are a volume scale — 50 units means 0.50 mL, 100 units means 1.00 mL. Multiplying mL by 100 converts volume into the unit marks you read on the syringe barrel.
How many units is 2.5 mg of tirzepatide?
At 5 mg/mL: 50 units (0.50 mL). At 2.5 mg/mL: 100 units (1.00 mL). At 10 mg/mL: 25 units (0.25 mL). The answer changes with each vial concentration, so always verify the mg/mL printed on your vial label before drawing. Enter the exact values into the calculator for your specific vial.
What is the difference between semaglutide and tirzepatide?
Semaglutide is a GLP-1 receptor agonist (brand names: Ozempic® for type 2 diabetes, Wegovy® for chronic weight management). Tirzepatide is a dual GIP/GLP-1 receptor agonist (brand names: Mounjaro® for type 2 diabetes, Zepbound® for obesity). Both are once-weekly subcutaneous injections. The dose conversion math is identical — the only variable is the vial concentration.
Can I use an insulin syringe for GLP-1 injections?
U-100 insulin syringes are commonly used with injectable GLP-1 medications dispensed in vials. They offer precise volume markings suited for small subcutaneous doses. Whether a U-100 syringe is appropriate for your specific prescription is a clinical question — your prescribing provider or pharmacist should confirm the syringe type, needle gauge, and injection technique for your medication.
What if my vial concentration is not listed in the calculator?
Select "Custom" from the concentration dropdown and type your vial's exact concentration in mg/mL. The number is printed on the vial label — for example, it may read "5 mg/mL" or "10 mg/1 mL". If you are unsure of the concentration, contact the pharmacy that dispensed your medication before drawing a dose.
Sources & References
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