Peptide Reconstitution Calculator
Pick the syringe in your hand.
Dose per injection. 1 mg = 1000 mcg.
Enter a vial size, dose and water volume to see where to pull.
Enter the draw you want, and we set the water to match.
For tracking and calculation purposes only. Not medical advice. Based on a standard U-100 insulin syringe.
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The numbers here describe your own vial. They are not medical advice and not a dose suggestion. Confirm your protocol with a qualified clinician.
How the units are worked out
Your vial holds a fixed amount of peptide. The water you add sets the concentration (how much peptide sits in each millilitre). The concentration then decides how much liquid carries your dose.
Three steps, in order:
- Concentration (mcg/mL) = peptide in the vial (mcg) divided by water added (mL).
- Volume (mL) = your dose (mcg) divided by the concentration (mcg/mL).
- Units to draw = volume (mL) multiplied by 100.
That last step is the syringe, not the peptide. A U-100 insulin syringe is marked so 100 units hold 1 mL, so 0.1 mL reads as 10 units.
A worked example
Enter your dose in the calculator above and this line shows the numbers worked through.
Water and units at a glance
your vial at different mixes. Every row opens the calculator on that mix.
| Vial | Water | Concentration |
|---|---|---|
| 10 mg | 1 mL | 10,000 mcg/mL |
| 10 mg | 2 mL | 5,000 mcg/mL |
| 10 mg | 3 mL | 3,333 mcg/mL |
| 10 mg | 5 mL | 2,000 mcg/mL |
Units appear once you enter a dose.
The pre-filled vial and water are an example: the most-used BPC-157 vial and water amounts in WPA dosing data (Aug 2026). There is no pre-filled dose. Not a recommendation.
Mixing and storage
Run the water down the inside wall of the vial and let the powder dissolve on its own. Never shake it. Label the vial with the compound, the total mass, the water you added, the concentration and the date. A sealed freeze-dried vial keeps 12 to 24 months in the fridge at 2 to 8°C. Once mixed with preserved water, such as bacteriostatic water, that drops to roughly 28 days refrigerated. Keep it at the back of the fridge, away from light and away from the door's temperature swings.
Questions
How do I work out the units to draw?
Does the water I add change my dose?
What does U-100 mean on a syringe?
My draw is bigger than the syringe. What now?
Why does the calculator use micrograms?
Where do the pre-filled numbers come from?
Get the Reconstitution Quick-Reference Card
The formula, two worked examples, the mixing method, common errors, and a shelf-life table, all on one printable card for your bench. Free PDF, straight to your inbox.
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