How many units is 100 mcg?
100 mcg is 4 units on a U-100 insulin syringe when the solution is 2.5 mg/mL (5 mg mixed with 2 mL of water). The number changes with the concentration, so check your own mix against the table below.
100 mcg in units at every common concentration
| Concentration | Made by mixing | Units | Volume |
|---|---|---|---|
| 1 mg/mL | 2 mg in 2 mL, or 5 mg in 5 mL | 10 units | 0.1 mL |
| 2 mg/mL | 10 mg in 5 mL | 5 units | 0.05 mL |
| 2.5 mg/mL | 5 mg in 2 mL | 4 units | 0.04 mL |
| 3.33 mg/mL | 10 mg in 3 mL | 3 units | 0.03 mL |
| 5 mg/mL | 5 mg in 1 mL, or 10 mg in 2 mL | 2 units | 0.02 mL |
| 10 mg/mL | 10 mg in 1 mL, or 20 mg in 2 mL | 1 units | 0.01 mL |
How do you work out the units for 100 mcg?
- Find your concentration: the peptide in the vial divided by the water you added. 5 mg in 2 mL is 2.5 mg/mL.
- Convert to micrograms per unit: multiply by 1,000, then divide by 100. 2.5 mg/mL is 25 mcg per unit.
- Divide the amount by that figure: 100 mcg divided by 25 is 4 units.
Or let the mcg to units converter do it from your own vial and water.
What to watch for with 100 mcg
- At strong concentrations 100 mcg comes to under 2 units, which is hard to measure accurately: a U-100 syringe is usually marked in 1 or 2 unit steps, so a single tick is a large share of the amount. A weaker mix, or a U-30 or U-50 syringe with finer markings, makes small amounts easier to read.
- 100 mcg is 0.1 mg. Vials are labelled in milligrams while amounts are often discussed in micrograms, so converting both to the same unit first avoids a thousandfold error.
Common questions
How many units is 100 mcg on an insulin syringe?
It depends on the concentration of the solution. At 2.5 mg/mL (5 mg mixed with 2 mL of water), 100 mcg is 4 units on a U-100 syringe. At 5 mg/mL it is 2 units, and at 1 mg/mL it is 10 units.
How do I convert 100 mcg to units myself?
Multiply the concentration in mg/mL by 1,000 to get micrograms per mL, divide by 100 to get micrograms per unit on a U-100 syringe, then divide 100 mcg by that figure. At 2.5 mg/mL that is 25 mcg per unit, so 100 divided by 25 is 4 units.
Is 100 mcg a recommended amount?
No. This page converts an amount into syringe units; it does not suggest that anyone take it. Whether and how much of any substance to use is a decision for you and a licensed clinician.
Unit conversion only. This page does not recommend an amount of any substance and is not medical advice.
PepCue does this conversion for every vial you log, so you never re-derive it. Free on iPhone and Android.