Your vial says milligrams. Your syringe says units. This converts one into the other — enter your vial size, how much bacteriostatic water you added, and the dose you want.
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Vial sizes and dose ranges come from the app's own compound entries.
A U-100 insulin syringe holds 1 mL spread across 100 marks, so one unit is 0.01 mL. Nothing about peptides is special here — it is a volume conversion:
| Step | What you do |
|---|---|
| 1. Concentration | vial mg ÷ water mL — a 5 mg vial in 2 mL is 2.5 mg/mL |
| 2. Volume | dose ÷ concentration — 2.5 mg ÷ 2.5 mg/mL is 1 mL |
| 3. Units | volume × 100 — 1 mL is 100 units |
Because the water is the variable, and nobody tells you that part. The same 5 mg vial and the same 2.5 mg dose:
| Water added | Concentration | Units for 2.5 mg |
|---|---|---|
| 1 mL | 5 mg/mL | 50 units |
| 2 mL | 2.5 mg/mL | 100 units — the whole syringe |
| 3 mL | 1.67 mg/mL | 150 units — does not fit |
More water is not "weaker" — the dose is identical. It only changes how many marks you draw, and whether that number is readable on your syringe.
There is no correct answer, only trade-offs. Aim for your usual dose to land somewhere in the middle of the syringe, where the marks are easy to read and a small error in reading does not change the dose much. A dose that lands at 4 units is hard to measure accurately; the same dose at 40 units is not.
The app has this calculator plus the reported doses, protocols and cited sources for 57 compounds — and it flags when a dose will not fit your syringe or when your vial runs past its stability window. Free, no account needed.
Get it on the App StoreDepends entirely on your water. A 5 mg vial with 1 mL gives 50 units; the same vial with 2 mL gives 100 units. Run your own numbers above.
You can, but the markings are in mL, not units. This calculator shows both — the mL figure is under the units.
It will not fit in one U-100 draw. Either use less water when you reconstitute, so the same dose takes fewer units, or split it into two injections. The calculator warns you when this happens.
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