Dosage calculation
How to know how many syringe units equal your dose.
Basics
When you reconstitute a peptide, you get a concentration: the amount of peptide in each milliliter of liquid.
Concentration = mg of peptide ÷ mL of water added
Insulin syringes are not measured in milliliters but in units (IU). The equivalence is simple:
1 mL = 100 units (IU)
Step-by-step example
Imagine a 5 mg vial of peptide to which you add 2 mL of bacteriostatic water:
- Concentration: 5 mg ÷ 2 mL = 2.5 mg per mL.
- Since 1 mL = 100 IU, each IU contains: 2.5 mg ÷ 100 = 0.025 mg = 25 mcg per IU.
If you want a 250 mcg dose:
250 mcg ÷ 25 mcg per IU = 10 IU in the syringe
That is, you would fill the syringe up to the 10-unit mark.
Quick rule
Units to inject = desired dose (mcg) ÷ mcg per unit
And the mcg per unit come from dividing the total micrograms in the vial by the total units of liquid you added.
Automatic calculator
If you don't want to do the math by hand, use our calculator: enter the data and it tells you the exact units to draw in the syringe.
This information is educational only and does not replace medical advice; always consult a healthcare professional.