Peptide Reconstitution & Concentration Calculator
Enter how much peptide is in the vial, how much diluent you add, and the amount you need per aliquot. The calculator returns the concentration of the solution and the exact volume to draw. All math runs in your browser.
Concentration = mg ÷ mL. Volume = amount needed ÷ concentration. 1 mg = 1,000 mcg; 1 mL = 1,000 µL.
How the math works
Reconstitution is a dilution problem with two steps. First, the concentration: divide the mass of peptide by the volume of diluent. A 10 mg vial dissolved in 2 mL gives 5 mg/mL, which is 5,000 mcg/mL. Second, the volume to draw: divide the amount you need by that concentration. For 250 mcg at 5,000 mcg/mL, that is 0.05 mL, or 50 µL.
Adding more diluent does not change how much peptide is in the vial. It only spreads it over a larger volume, which makes each microlitre weaker and small volumes easier to measure accurately.
Quick reference: concentration by vial size
| Peptide in vial | + 1 mL | + 2 mL | + 3 mL |
|---|---|---|---|
| 2 mg | 2 mg/mL | 1 mg/mL | 0.67 mg/mL |
| 5 mg | 5 mg/mL | 2.5 mg/mL | 1.67 mg/mL |
| 10 mg | 10 mg/mL | 5 mg/mL | 3.33 mg/mL |
| 15 mg | 15 mg/mL | 7.5 mg/mL | 5 mg/mL |
Before you reconstitute
- Use the right diluent. Bacteriostatic water for vials you will open more than once; sterile water only for single use. See bacteriostatic vs sterile water.
- Check the real amount. The label says 10 mg, but the COA tells you what was measured. See how to read a COA.
- Follow a clean method. Step-by-step technique is in how to reconstitute peptides.
- Plan storage. Reconstituted solutions are typically kept at 2–8 °C for about 28 days. See how long reconstituted BPC-157 lasts.
Frequently asked questions
How do I calculate peptide concentration?
Divide the mass of peptide in the vial by the volume of diluent added. For example, 5 mg in 2 mL gives 2.5 mg/mL, or 2,500 mcg/mL.
How much bacteriostatic water should I add to a 10 mg vial?
There is no single correct volume. In laboratory practice 1 to 3 mL is common: more diluent gives a weaker solution, which makes small amounts easier to measure precisely.
How many mcg are in 1 mg?
1 mg equals 1,000 mcg (micrograms).
How do I convert mL to µL?
Multiply by 1,000. For example, 0.05 mL equals 50 µL.
Does adding more water reduce the amount of peptide?
No. The total amount in the vial stays the same; extra diluent only lowers the concentration per millilitre.
This calculator performs unit conversions for laboratory solution preparation. It is not medical or dosing advice. All TrueLabs products are sold for in vitro and laboratory research use only and are not intended for human or veterinary use.