Concentration
5 mg/ml
Reconstitution calculator
Turn a vial into the exact units you draw.
Enter the peptide mass, the bacteriostatic water you are adding, and your target dose. You get the precise mark to draw to on an insulin syringe, and how many doses the vial holds.
Draw to this mark
10 units0.10 ml on a U-100 syringe
Draw volume
0.10 ml
U-40 units
4 units
Doses per vial
20
How reconstitution works
The maths is one division. Concentration is mass over volume, and your draw is dose over concentration. The rest is handling.
01
Find the concentration
Divide the peptide mass by the water you add. A 10 mg vial in 2 ml is 5 mg/ml.
02
Add water down the wall
Inject slowly against the inside of the vial so it runs onto the powder instead of striking it.
03
Swirl, never shake
Roll it gently until clear. Shaking can shear and damage some peptides.
What this tool does not do
It will not tell you how much to take or how long to run a compound. For many research peptides that evidence does not exist in humans, and a calculator pretending otherwise would be guessing. Dose and protocol decisions belong with a qualified clinician.
Common questions
The things people get wrong first, answered plainly.
How much bacteriostatic water should I add?
Any amount you like. The water volume does not change how much peptide is in the vial, only the concentration. More water gives a larger, easier-to-read draw for small doses; less water gives a smaller one. Pick a volume that lands your dose on a clean number of units, then recalculate above.
What is an insulin syringe unit?
On a standard U-100 syringe, 100 units is 1 ml, so one unit is 0.01 ml. A U-40 syringe marks 40 units per ml. The unit is a volume marking, not a fixed amount of peptide, which is why the same dose lands on different marks depending on your concentration.
Can the wrong water amount change my dose?
It does not change the total peptide in the vial, but it changes how many units you draw for a given dose. If you reconstitute with a different volume than you planned, recalculate before drawing.
mg, mcg, units, which is which?
mg and mcg measure the actual peptide mass (1 mg is 1000 mcg). Units are the syringe's volume marks. This tool converts your mass dose into the right volume, then into units for your syringe.
How should I store it after mixing?
Most reconstituted peptides are kept refrigerated and used within a window that varies by compound. Lyophilised powder before mixing is generally more stable. Check storage guidance for the specific peptide rather than assuming.