WeightSnap Tools / Reconstitution calculator
Enter your vial size, how much bacteriostatic water you add, and your dose. Get the concentration, the volume to draw, and the insulin syringe units. Works for any peptide. Free, instant, nothing to install.
Reconstitution is one division and one multiplication. The water you add sets the concentration, and the concentration converts your dose into a syringe reading.
Worked example: a 10 mg vial with 2 mL of bacteriostatic water gives 5 mg/mL. A 2.5 mg dose is 2.5 ÷ 5 = 0.5 mL. On a U-100 insulin syringe, 0.5 mL reads as 50 units. The same vial with 1 mL of water would be 10 mg/mL, and the same dose would read 25 units.
More water never changes how much peptide is in the vial, only how dilute it is. People usually pick a water volume that makes their dose land on a round syringe number.
| Dose | 2.5 mg/mL | 5 mg/mL | 10 mg/mL |
|---|---|---|---|
| 0.25 mg | 10 units | 5 units | 2.5 units |
| 0.5 mg | 20 units | 10 units | 5 units |
| 1 mg | 40 units | 20 units | 10 units |
| 2.5 mg | 100 units | 50 units | 25 units |
| 5 mg | 200 units | 100 units | 50 units |
A U-100 insulin syringe holds 100 units (1 mL). Entries over 100 units will not fit in a single 1 mL syringe.
Peptides usually ship as a freeze-dried powder. Reconstitution is adding a liquid, most often bacteriostatic water, so the powder dissolves and can be measured with a syringe. The amount of water sets the concentration; it never changes the total amount of peptide in the vial.
Any amount works mathematically. More water means a more dilute mix and a larger volume per dose. Most people choose a volume that puts their dose on an easy syringe number, like the 10 mg + 2 mL example above. For anything specific to your prescription, ask your pharmacist or provider.
It depends entirely on your concentration. Divide your dose in mg by the concentration in mg/mL to get mL, then multiply by 100 for U-100 units. The calculator above does this for you.
Yes. The math is identical for anything measured in milligrams and dissolved in a known volume, from compounded GLP-1 medications to research peptides like BPC-157 or ipamorelin.
No. This is an arithmetic tool: it converts the numbers you enter. It does not recommend doses or products. Always confirm anything affecting your health with your pharmacist or healthcare provider.
WeightSnap is a tracking tool, not medical advice. This calculator performs arithmetic on the numbers you enter and makes no recommendations. Always work with your healthcare provider.
WeightSnap