Peptide calculator: reconstitution and dose to units

Worked example

A 5 mg vial reconstituted with 2 mL of bacteriostatic water gives a concentration of2.5 mg/mL. A dose written as 250 mcg is0.25 mg, so the draw is 0.1 mL — 10 units on a U-100 syringe. That vial holds 20 doses of that size.

These are example numbers to show the arithmetic, not a dose for anyone. Type your own values above.

How the math works

Three divisions, no assumptions:

A U-100 insulin syringe is marked in units where 100 units = 1 mL, whatever the barrel size. 0.3 mL, 0.5 mL and 1 mL barrels hold 30, 50 and 100 units. The gauge above shows whether your draw fits the barrel you picked.

Milligrams and micrograms convert at 1 mg = 1000 mcg. Units such as IU are not mass units and cannot be converted here; the tool shows no result rather than guessing.

What this calculator does not do

• It does not suggest, calculate or adjust a dose. The dose field is for the dose you were given.
• It does not know your compound, your vial or your prescription. Check every value against the vial label and your prescriber's instructions.
• It does not account for the small volume of powder in the vial or for dead space in the syringe.

Reading the syringe ruler

The table under the gauge is a reverse lookup: for each round mark on the barrel, how much of the vial's contents that volume holds at your concentration. Use it to double-check the mark you are drawing to. It is not a list of doses to choose from.

Keep the numbers with the doses

In STACK the calculator writes the concentration onto the vial you are using, so every dose you log carries its draw volume and units, and the vial's remaining doses count down as you go.

Converts the dose you enter into syringe units for the vial and diluent you enter. It does not tell you what dose to take. Confirm every calculation with your prescriber or pharmacist.

Read the guide