Peptide reconstitution calculator
Enter vial size, bacteriostatic water volume, and target dose. Get concentration, mL per dose, insulin-syringe units, and total doses per vial.
Inputs
All values numeric. Tab through fields or click to edit.
Results
Live — updates as you type.
Common reconstitution patterns
These are the most-cited starting points for the molecules in our catalog — useful as a sanity-check on your own protocol math.
| Peptide | Vial | Typical BAC water | Resulting concentration |
|---|---|---|---|
| Semaglutide | 5 mg | 2 mL | 2.5 mg/mL |
| Tirzepatide | 10 mg | 1-2 mL | 5-10 mg/mL |
| Retatrutide | 10 mg | 1-2 mL | 5-10 mg/mL |
| BPC-157 | 5 mg | 1-2 mL | 2.5-5 mg/mL |
| TB-500 | 10 mg | 2 mL | 5 mg/mL |
| GHK-Cu | 50 mg | 5 mL | 10 mg/mL |
| CJC-1295 (either) | 2 mg | 1-2 mL | 1-2 mg/mL |
| Ipamorelin | 5 mg | 1-2 mL | 2.5-5 mg/mL |
| Sermorelin | 5 mg | 1-2 mL | 2.5-5 mg/mL |
| DSIP | 5 mg | 2.5 mL | 2 mg/mL |
| Selank / Semax | 5 mg | 1-2 mL | 2.5-5 mg/mL |
| NAD+ | 500 mg | 5 mL | 100 mg/mL · use immediately |
| PT-141 | 10 mg | 2 mL | 5 mg/mL |
Frequently asked questions
What is bacteriostatic water and why is it used?
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Bacteriostatic water for injection (BAC water) is sterile water containing 0.9% benzyl alcohol as a preservative. The preservative inhibits bacterial growth, which lets a reconstituted vial be used for multiple draws over up to about 28 days under refrigeration. Plain sterile water can also be used but is best for single-use immediately after reconstitution.
How do insulin syringe units convert to mL?
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A standard U-100 insulin syringe is graduated so that 100 units = 1 mL. Each unit on the barrel is therefore 0.01 mL. So 25 units = 0.25 mL, 50 units = 0.5 mL, and so on. This calculator outputs the unit count directly so you don't have to do the mL-to-unit conversion manually.
Does the reconstitution volume matter for potency?
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The mass of peptide in the vial is fixed at manufacture; the reconstitution volume only changes the concentration. Diluting more (more BAC water) means each volume contains less peptide, so larger draw volumes are needed per dose. Diluting less means smaller, harder-to-measure draws. Most published protocols target a concentration that gives doses in the 10-50 unit range on a U-100 syringe.
How long is reconstituted peptide stable?
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Stability varies by peptide. As a rough guide for most research peptides: in bacteriostatic water at 2-8°C, expect 4-8 weeks of stability for shorter peptides (BPC-157, ipamorelin, sermorelin) and up to 12 weeks for longer-acting analogs with stabilizing modifications (semaglutide, tirzepatide, CJC-1295 DAC). Specific stability data is provided on each batch's COA.
Should I account for acetate content?
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Some peptides (semaglutide, tirzepatide, many GH secretagogues) ship as acetate salts. The acetate counterion adds mass that is not peptide. If your protocol is sensitive to effective peptide dose, multiply the gross vial mass by the peptide-content percentage on the COA before running this calculator. For most general protocols within ±5%, this correction is not necessary.
This calculator is provided for laboratory research reference. It is not medical advice and not a dosing recommendation for human or veterinary use. Always cross-check protocol numbers against your primary literature source and your institution's biosafety guidance.