Guide
Converting syringe units to mg and mcg
Syringe “units” measure volume, not amount. The amount of peptide in 10 units depends entirely on how the vial was reconstituted.
The basics
- U-100 insulin syringe: 100 units = 1 mL, so 1 unit = 0.01 mL.
- 1 mg = 1,000 µg (mcg).
- Amount in a dose = volume × concentration.
mg in a draw = (units ÷ 100) × concentration (mg/mL)
Conversion table
Amount of peptide in a given number of units, by concentration:
| Units | 1 mg/mL | 2.5 mg/mL | 5 mg/mL | 10 mg/mL |
|---|---|---|---|---|
| 5 | 50 µg | 125 µg | 250 µg | 500 µg |
| 10 | 100 µg | 250 µg | 500 µg | 1 mg |
| 20 | 200 µg | 500 µg | 1 mg | 2 mg |
| 25 | 250 µg | 625 µg | 1.25 mg | 2.5 mg |
| 50 | 500 µg | 1.25 mg | 2.5 mg | 5 mg |
| 100 | 1 mg | 2.5 mg | 5 mg | 10 mg |
Units vs IU
Syringe units are not the same as International Units (IU). IU is a measure of biological activity used for hormones like HGH and insulin; 1 IU of insulin happens to be 1 syringe unit because U-100 insulin contains 100 IU per mL. For peptides measured in mg, ignore IU and work from concentration.
Reconstitution calculator
Vial presets:
Arithmetic aid for laboratory reconstitution. It does not recommend any amount for any use.
Frequently asked questions
How many mg is 10 units?
It depends on concentration. At 5 mg/mL, 10 units (0.1 mL) contains 0.5 mg; at 10 mg/mL it contains 1 mg.
How many units is 250 mcg?
At 2.5 mg/mL it is 10 units; at 5 mg/mL it is 5 units; at 1 mg/mL it is 25 units.
How many units are in 1 mL?
On a U-100 syringe, 100 units = 1 mL.