"How many units of semaglutide" has the same answer as the tirzepatide version of the question: a unit is a volume, so the milligrams in it depend on the concentration printed on the vial. What changes for semaglutide is the scale. Its doses are fractions of a milligram, so at the most common compounded concentration the starting dose is five units, and a misread mark multiplies the dose rather than nudging it. This page sets out the formula once, then gives both tables at the concentrations found on a dated pharmacy page and the two current labels (read 2026-10-07). It reports arithmetic; it recommends no amount.
The label steps, the vial arithmetic and the trial record are on the semaglutide dosage page; the same tables for tirzepatide, at its higher concentrations, are on tirzepatide units.
The formula
A U-100 insulin syringe holds 100 units per millilitre; the insulin syringe units page sets out the barrel sizes and their markings. The conversion is:
units = amount (mg) ÷ concentration (mg/mL) × 100, and in reverse mg = units ÷ 100 × concentration.
Milligrams to units
Rows are the WEGOVY and OZEMPIC label steps; columns are the compounded concentrations listed on the pharmacy chart page read for this page.
| Amount | 2.5 mg/mL | 5 mg/mL | 7.5 mg/mL | 10 mg/mL |
|---|---|---|---|---|
| 0.25 mg | 10 units | 5 units | 3.3 units | 2.5 units |
| 0.5 mg | 20 units | 10 units | 6.7 units | 5 units |
| 1 mg | 40 units | 20 units | 13.3 units | 10 units |
| 1.7 mg | 68 units | 34 units | 22.7 units | 17 units |
| 2 mg (Ozempic maximum) | 80 units | 40 units | 26.7 units | 20 units |
| 2.4 mg | 96 units | 48 units | 32 units | 24 units |
| 7.2 mg (WEGOVY HD) | 288 units | 144 units | 96 units | 72 units |
Read as sentences: at 5 mg/mL, 0.25 mg = 0.05 mL = 5 units, and 2.4 mg = 48 units. At 2.5 mg/mL, 2.4 mg = 0.96 mL = 96 units, nearly a full 1 mL barrel. At 10 mg/mL, every milligram is 10 units.
Two consequences. At 7.5 mg/mL the first two steps fall between marks (3.3 and 6.7 units), which the pharmacy page gives as the reason that concentration is rare. And the newest label strength, 7.2 mg, fits a single 1 mL syringe only at 7.5 mg/mL or above.
Units to milligrams
The reverse lookups ("how many mg is 40 units", "20 units is how many mg") are most of what is searched. Same four concentrations:
| Units (mL) | 2.5 mg/mL | 5 mg/mL | 7.5 mg/mL | 10 mg/mL |
|---|---|---|---|---|
| 5 (0.05 mL) | 0.125 mg | 0.25 mg | 0.375 mg | 0.5 mg |
| 10 (0.10 mL) | 0.25 mg | 0.5 mg | 0.75 mg | 1 mg |
| 15 (0.15 mL) | 0.375 mg | 0.75 mg | 1.125 mg | 1.5 mg |
| 20 (0.20 mL) | 0.5 mg | 1 mg | 1.5 mg | 2 mg |
| 25 (0.25 mL) | 0.625 mg | 1.25 mg | 1.875 mg | 2.5 mg |
| 30 (0.30 mL) | 0.75 mg | 1.5 mg | 2.25 mg | 3 mg |
| 40 (0.40 mL) | 1 mg | 2 mg | 3 mg | 4 mg |
| 50 (0.50 mL) | 1.25 mg | 2.5 mg | 3.75 mg | 5 mg |
| 60 (0.60 mL) | 1.5 mg | 3 mg | 4.5 mg | 6 mg |
| 75 (0.75 mL) | 1.875 mg | 3.75 mg | 5.625 mg | 7.5 mg |
Every row spans a fourfold range. Ten units is the label's 0.25 mg starting step at 2.5 mg/mL and four times that, 1 mg, at 10 mg/mL. The same pharmacy page that lists the concentrations shows one 30 mg order arriving as 12, 6, 4 or 3 mL; a person who moves from one to another and keeps drawing the same unit count has changed the amount by up to four times without touching a different mark.
What the labelled pens deliver, in units
| Presentation (label read 2026-10-07) | Concentration | Volume per dose | As U-100 units |
|---|---|---|---|
| WEGOVY single-dose pens 0.25, 0.5, 1 mg | 0.5, 1, 2 mg/mL | 0.5 mL | 50 |
| WEGOVY single-dose pens 1.7, 2.4, 7.2 mg | 2.27, 3.2, 9.6 mg/mL | 0.75 mL | 75 |
| WEGOVY FlexTouch 9.6 mg/3 mL, 2.4 mg doses | 3.2 mg/mL | 0.75 mL | 75 |
| OZEMPIC pen 2 mg/3 mL, 0.25 mg dose | 0.68 mg/mL | ≈0.37 mL | ≈37 |
| OZEMPIC pens, 0.5, 1 and 2 mg doses | 0.68, 1.34, 2.68 mg/mL | ≈0.75 mL | ≈75 |
The pattern mirrors tirzepatide: the labelled products hold the volume nearly fixed and change the concentration, so a unit count read off a pen tells nothing about strength. The pens are not marked in units and deliver the whole dose; units appear only when liquid is drawn into a syringe from a vial. Pen clicks, a different scale again, are on Ozempic pen clicks.
The error the units scale invites
FDA's alert on compounded semaglutide (content current as of 2024-07-26) described adverse event reports in which patients drew five to 20 times the intended dose from multiple-dose vials, and named confusion between millilitres, milligrams and "units" as a likely contributor. The tables above show how that range arises: at 10 mg/mL the 0.25 mg step is 2.5 units, so a draw of 25 units, the number "0.25" read as a unit count, is 2.5 mg, ten times the step, and a draw of 50 units is twenty times. The general mg–mcg–mL slips are on mg to units.
What this page does not establish
No label publishes a semaglutide amount in syringe units; every figure here is arithmetic on a stated concentration, and a compounded or research vial is only as accurate as its label. For a lyophilised research vial the concentration is set by the water added, which the semaglutide reconstitution page and the semaglutide calculator work through for any vial and volume. Every GLP-1 product side by side is on the GLP-1 dosage chart, and the compound is covered in Medibact's Semaglutide guide. Nothing here is a suggested amount; decisions about amounts belong with a prescriber.
Sources and dates
Opened 2026-10-07: the WEGOVY label (DailyMed set id ee06186f-2aa3-4990-a760-757579d8f77b, effective 2026-06-18) and the OZEMPIC injection label (set id adec4fd2-6858-4c99-91d4-531f5f2a2d79, effective 2026-06-01), sections 2 and 3, via the DailyMed web services; the compounded semaglutide chart on formblends.com (published 2026-05-01, modified 2026-10-01); FDA's alert "FDA alerts health care providers, compounders and patients of dosing errors associated with compounded injectable semaglutide products" (content current as of 2024-07-26). All unit and milligram arithmetic by this site. Corrections go to the contact page.