How many mg is 20 units of semaglutide?

Twenty units is 0.2 mL. At 2.5 mg/mL that is 0.5 mg; at 5 mg/mL it is 1 mg; at 1 mg/mL it is 0.2 mg. The concentration on your vial's label decides which.

How many units is 0.5 mg of semaglutide?

At 2.5 mg/mL, 0.5 mg is 20 units. At 5 mg/mL it is 10 units, and at 1 mg/mL it is 50 units. Find your vial's concentration first; the milligrams alone do not give a mark.

How many mg is 50 units of semaglutide?

Fifty units is 0.5 mL: 1.25 mg at 2.5 mg/mL, 2.5 mg at 5 mg/mL, 0.5 mg at 1 mg/mL. Doses of semaglutide are small enough that a misread line matters, so confirm the mark with the pharmacy.

How do you convert a semaglutide dose from mg to units?

Divide the dose in mg by the concentration in mg/mL, then multiply by 100 for a U-100 syringe. FDA's own example of an error: a dose meant to be 0.25 mg, or 5 units at 5 mg/mL, was prescribed as 25 units, five times the intended amount.

Tools

Semaglutide dosage calculator: mg to units

Reviewed September 2026

Quick answer

Units = mg ÷ mg/mL × 100. For compounded semaglutide the numbers are small: at 2.5 mg/mL a 0.25 mg dose is 10 units, and at 5 mg/mL it is 5 units. Your pharmacy chose your vial’s strength, so the concentration has to come off your own label before any of this means anything.

FDA has received reports of people injecting five to 20 times their intended semaglutide dose from compounded vials, with confusion between milligrams, milliliters and units named as a cause.¹ This tool converts the numbers you enter and never suggests a dose. If its answer differs from what your pharmacy told you, stop and call them.

What is on your vial

Concentration printed on the vial

mg/mL

Read it off the label in front of you. A vial labeled “10 mg per mL” is 10. If it gives a total and a volume instead — say 60 mg in 3 mL — divide: that is 20.

The dose you were prescribed

The number your prescriber set. This tool converts it; it does not choose it.

Units on a U-100 syringe

Put in the strength printed on your vial and the dose you were prescribed. The mark on the syringe appears here.

A U-100 syringe is marked in hundredths of a milliliter, so 100 units is 1 mL. If yours is marked differently, this number does not apply to it.

Mixing from a powder? Get the concentration from the reconstitution calculator first; it passes the result back to this page.

Why a pen user never sees units

Wegovy is supplied in pens that each deliver a set dose, from 0.25 mg to 7.2 mg. Nothing is drawn up, so there is no unit to count.² Units belong to vials. FDA’s alert concerns compounded semaglutide in multiple-dose vials, and that is where the conversion went wrong.

The mistakes FDA saw

Patients told to draw 5 units on a 1 mL syringe drew 50. Prescribers made the same slip: one wrote 25 units for a 0.25 mg dose, another 20 units where 2 were meant. FDA’s advice to prescribers who are unsure is to call the compounder about the calculation, and it asks that patients be given the right syringe size and shown how to measure.¹

The chart by vial strength is on semaglutide dosage in units.

Questions

How many mg is 20 units of semaglutide?: Twenty units is 0.2 mL. At 2.5 mg/mL that is 0.5 mg; at 5 mg/mL it is 1 mg; at 1 mg/mL it is 0.2 mg. The concentration on your vial's label decides which.
How many units is 0.5 mg of semaglutide?: At 2.5 mg/mL, 0.5 mg is 20 units. At 5 mg/mL it is 10 units, and at 1 mg/mL it is 50 units. Find your vial's concentration first; the milligrams alone do not give a mark.
How many mg is 50 units of semaglutide?: Fifty units is 0.5 mL: 1.25 mg at 2.5 mg/mL, 2.5 mg at 5 mg/mL, 0.5 mg at 1 mg/mL. Doses of semaglutide are small enough that a misread line matters, so confirm the mark with the pharmacy.
How do you convert a semaglutide dose from mg to units?: Divide the dose in mg by the concentration in mg/mL, then multiply by 100 for a U-100 syringe. FDA's own example of an error: a dose meant to be 0.25 mg, or 5 units at 5 mg/mL, was prescribed as 25 units, five times the intended amount.

Sources

FDA drug safety communication, 'FDA alerts health care providers, compounders and patients of dosing errors associated with compounded injectable semaglutide products', content current as of 07/26/2024
FDA prescribing information for WEGOVY (semaglutide), section 3, Dosage Forms and Strengths, revision 6/2026 DailyMed