Peptide Reconstitution Calculator
Enter your peptide vial size, bacteriostatic water volume, and desired dose to calculate exactly how many units to draw on your syringe.
Draw to this mark on your syringe
5 units
Concentration
50.0 mcg/unit
Doses per vial
40
Disclaimer: This tool is for informational and educational purposes only. It is not medical advice. Consult a qualified healthcare provider before using any compound.
PeptideStack does not endorse, recommend, or encourage the use of any peptide or compound.
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Frequently Asked Questions
How do I reconstitute a peptide?
To reconstitute a peptide, slowly inject bacteriostatic water into the vial along the glass wall — do not spray directly onto the powder. Gently swirl (never shake) until the powder is fully dissolved. The solution should be clear. Store reconstituted peptides in the refrigerator.
What is bacteriostatic water?
Bacteriostatic water (BAC water) is sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth. It is the standard diluent for reconstituting peptides because it extends the shelf life of the solution compared to plain sterile water.
How many doses are in a peptide vial?
The number of doses depends on the vial size (mg) and your dose (mcg). For example, a 10 mg vial at 250 mcg per dose yields 40 doses. Use the calculator above to find your specific number.
What size syringe should I use for peptides?
Most peptide users use a 100-unit (1 mL) insulin syringe with a 29–31 gauge needle for subcutaneous injection. A 50-unit (0.5 mL) syringe can be easier to read for very small doses. Both are supported by this calculator.
Does the amount of water I add change the dose?
No — the total peptide in the vial stays the same regardless of how much water you add. More water means a more dilute solution, so you draw more units per dose. Less water means a more concentrated solution and fewer units per dose. The calculator handles this math for you.