A semaglutide dosage chart in units only works for one concentration. Change the vial and every number in it changes. The doses come from the label. The units come from arithmetic. What a month of those doses costs is in the semaglutide cost guide.
Brand semaglutide, such as Wegovy, is dosed in milligrams. Compounded semaglutide may come in multiple-dose vials[2]. Its instructions may give the dose in units[2]. The chart below bridges the two.
The label’s dose ladder
The Wegovy label starts at 0.25 mg once a week[1]. It steps up every four weeks: 0.5 mg, then 1 mg, then 1.7 mg[1]. For adult weight reduction, the maintenance dose is 1.7 mg or 2.4 mg, with 2.4 mg recommended[1].
The label adds a higher step. After at least four weeks on 2.4 mg, it allows up to 7.2 mg for some adults[1]. That dose ships as the Wegovy HD pen[1]. It is left out of the chart.
The chart, at two concentrations
One unit on a U-100 syringe is 0.01 mL. FDA describes a 5-unit dose on that syringe as 0.05 milliliter[2]. So units = milligrams ÷ milligrams per mL × 100.
| Label dose | At 2.5 mg/mL | At 5 mg/mL |
|---|---|---|
| 0.25 mg (weeks 1 to 4) | 10 units | 5 units |
| 0.5 mg (weeks 5 to 8) | 20 units | 10 units |
| 1 mg (weeks 9 to 12) | 40 units | 20 units |
| 1.7 mg (weeks 13 to 16) | 68 units | 34 units |
| 2.4 mg (week 17 on) | 96 units | 48 units |
The two columns are examples, not products. FDA says concentrations vary between compounders, and one compounder may sell several[2]. Read your own vial’s mg/mL before using any chart.
Why 5 mg/mL? FDA’s alert describes a provider who meant 0.25 mg and wrote it as 5 units[2]. Those two figures only agree at 5 mg/mL. That is arithmetic on the alert, not a figure FDA states.
What four weeks draws from the vial
A chart per dose hides the monthly total. Four weekly doses is the unit a vial is sold against. At the 5 mg/mL example:
| Weekly dose | Per 28 days | Drawn |
|---|---|---|
| 0.25 mg | 1 mg | 20 units (0.2 mL) |
| 0.5 mg | 2 mg | 40 units (0.4 mL) |
| 1 mg | 4 mg | 80 units (0.8 mL) |
| 1.7 mg | 6.8 mg | 136 units (1.36 mL) |
| 2.4 mg | 9.6 mg | 192 units (1.92 mL) |
A month at 2.4 mg draws 192 units: nearly two full 1 mL syringes’ worth of liquid. At 2.5 mg/mL the same month needs twice the liquid. The milligrams, and so the drug cost, are identical.
FDA recommends using a compounded multi-dose vial within 28 days of first use[3]. What that cap does to milligrams per vial is in how long a vial of semaglutide lasts. Per-milligram prices are on the cost-per-milligram calculator.
Why Wegovy has no units chart
Wegovy’s cartons hold four single-dose pens, four single-dose syringes, or one FlexTouch pen[1]. Each delivers a set dose in milligrams. None is drawn from a vial.
The brand also changes concentration between doses. A 0.25 mg pen holds 0.25 mg in 0.5 mL[1]. A 2.4 mg pen holds 2.4 mg in 0.75 mL[1]. So a unit reading would mean something different on each pen. The FlexTouch pen is 3.2 mg/mL[1].
Checking a chart before you trust it
Any units chart a pharmacy sends should state three things:
- The concentration it was built for, in mg/mL.
- Each dose in milligrams beside its units.
- The syringe size, so the reading fits the barrel.
Test one row with the formula. If it does not hold, ask before the first injection. FDA advises patients to ask the prescriber or compounder how to measure the dose[2]. The same conversion for tirzepatide, including the brand vial readings, is in how many units is 2.5 mg of tirzepatide. Syringe sizes are covered in peptide needles and syringes.