Instantly calculate how much bacteriostatic water to add to any peptide vial. Get final concentration, injection volume, and a complete dosing reference table.
BAC water calculatorAny vial sizeU100 / U50 / 1mL syringeResearch use only
Step 1 — Vial Peptide Amount
5 mg
Step 2 — Bacteriostatic Water Added
2.0 mL
Step 3 — Desired Dose Per Injection
250 mcg
Step 4 — Syringe Type
Reconstitution Results
BAC Water to Add
2.0mL
Add to peptide vial
Final Concentration
2,500mcg/mL
= 2.5 mg/mL
Draw Per Injection
10units
For 250 mcg dose
Injections Per Vial
40
at 250 mcg each
Vial Fill Guide
Peptide
5 mg
BAC Water
2.0 mL
Dosing Reference Table
5 mg vial + 2.0 mL BAC water · 2,500 mcg/mL
Dose (mcg)
Volume (mL)
U100 Units
Injections Left
Days (1×/day)
How Peptide Reconstitution Works
Four steps to your exact injection volume.
1
Start with a lyophilized vialPeptides arrive as freeze-dried powder. The vial label shows total peptide content in milligrams (mg).
2
Choose your BAC water volumeAdding more water creates a lower concentration. Less water = higher concentration = smaller injections.
3
Calculate final concentrationConcentration (mcg/mL) = Total peptide (mcg) ÷ BAC water added (mL).
4
Use the draw volume for dosingDivide your desired dose (mcg) by the concentration (mcg/mL) to get the mL to draw, then convert to syringe units.
Setup: 10mg peptide vial + 2mL BAC water Concentration: 10,000 mcg ÷ 2mL = 5,000 mcg/mL Desired dose: 250 mcg → Draw = 250 ÷ 5,000 = 0.05 mL On U100 syringe: 0.05 mL × 100 = 5 units Injections per vial: 10,000 mcg ÷ 250 mcg = 40 injections
Common Questions
Frequently asked questions about peptide reconstitution and BAC water.
How much BAC water do I add to a 10mg peptide vial?
For a 10mg vial, adding 2mL of bacteriostatic water gives a concentration of 5,000 mcg/mL. Adding 1mL gives 10,000 mcg/mL. The right amount depends on your desired dose per injection — use the calculator above to dial in the exact volume for your protocol.
What is bacteriostatic water and why use it?
Bacteriostatic water (BAC water) is sterile water containing 0.9% benzyl alcohol, which inhibits bacterial growth and allows for multi-dose use. It is the standard diluent for reconstituting research peptides. Do not use plain sterile water for multi-draw vials, as it does not provide protection against contamination after the seal is broken.
Does adding more BAC water weaken the peptide?
No. The total amount of peptide in the vial stays the same — you're only changing the concentration. Adding more BAC water means you'll draw a larger volume per injection to get the same dose. The peptide itself is not weakened; each mcg retains the same activity regardless of solution volume.
How do I convert between U100, U50, and mL?
A U100 insulin syringe has 100 units per 1mL — so 1 unit = 0.01mL. A U50 syringe has 50 units per 1mL — so 1 unit = 0.02mL. To convert mL to U100 units: multiply by 100. To convert mL to U50 units: multiply by 50. Use the syringe selector in the calculator above to see your draw volume in the correct unit type.
How long does a reconstituted peptide vial last?
Once reconstituted with bacteriostatic water, most peptides remain stable for 4–6 weeks when refrigerated at 2–8°C and kept away from light. Lyophilized (dry) peptides typically last 12–24 months when stored frozen. Always discard if the solution appears cloudy or discolored.
What's the difference between this and a dosage calculator?
A reconstitution calculator (this tool) helps you figure out how much BAC water to add to a vial and what your final concentration will be. A dosage calculator helps you determine how many units to draw from an already-reconstituted vial to hit a specific dose. They're complementary tools used at different stages of the process.
⚠ Educational Research Tool Only. This calculator is an informational estimation tool for research planning purposes. All outputs are mathematical estimates based on your inputs. This tool does not constitute medical advice, clinical guidance, or a treatment recommendation. NuGenia Logics products are intended for licensed research professionals and qualified researchers only. Always consult a qualified healthcare professional before making any health-related decisions.
