For research purposes only
Peptide Reconstitution Calculator
Work out the concentration of a reconstituted vial and the volume that contains a given quantity of compound. Enter the vial size, the volume of bacteriostatic water added, and the quantity you want to measure. All figures are laboratory measurements of concentration and volume.
Your vial
The quantity stated on the vial, in milligrams.
The volume of solvent used to reconstitute the powder.
The quantity of compound you want in a single measured volume.
All three are the U-100 scale, so one unit is 0.01 mL on any of them. The unit figure is the same whichever you pick — a smaller barrel just spreads the same volume over more of its length.
Result
Marked position on a U-100 syringe
These figures are arithmetic only. They describe the concentration of a solution and the volume containing a stated quantity of compound. They are not instructions for use, and Apex OZ products are not supplied for human or veterinary use.
For research purposes only — not for human or veterinary useHow the calculation works
Reconstitution is the step where a lyophilised (freeze-dried) compound is returned to solution by adding a measured volume of bacteriostatic water. Two figures follow from it.
Concentration
Divide the quantity of compound in the vial by the volume of solvent added. A 10 mg vial reconstituted with 2 mL gives 5 mg per mL, or 5,000 mcg per mL.
The solvent volume changes the concentration, not the total quantity in the vial. The vial contains the same amount of compound whether you add 1 mL or 5 mL.
Volume for a stated quantity
Divide the quantity you want by the concentration. At 5 mg per mL, 250 mcg (0.25 mg) occupies 0.05 mL.
On a U-100 syringe, 1 mL is graduated into 100 units, so 0.05 mL falls at the 5 unit mark.
Common reconstitutions
Worked examples for products in the Apex OZ range, on a 1 mL U-100 syringe. Enter your own figures above for anything not listed.
| Vial | Water | Quantity | Concentration | Volume | Draw to | Portions |
|---|---|---|---|---|---|---|
| BPC-157 10 mg | 2 mL | 250 mcg | 5 mg/mL | 0.050 mL | 5 units | 40 |
| TB-500 10 mg | 2 mL | 500 mcg | 5 mg/mL | 0.100 mL | 10 units | 20 |
| MOTS-c 10 mg | 2 mL | 500 mcg | 5 mg/mL | 0.100 mL | 10 units | 20 |
| Semaglutide 5 mg | 2 mL | 250 mcg | 2.5 mg/mL | 0.100 mL | 10 units | 20 |
| Tirzepatide 20 mg | 2 mL | 2.5 mg | 10 mg/mL | 0.250 mL | 25 units | 8 |
| Retatrutide 10 mg | 2 mL | 1 mg | 5 mg/mL | 0.200 mL | 20 units | 10 |
| Melanotan 2 10 mg | 2 mL | 250 mcg | 5 mg/mL | 0.050 mL | 5 units | 40 |
| Kisspeptin-10 5 mg | 2 mL | 250 mcg | 2.5 mg/mL | 0.100 mL | 10 units | 20 |
| Selank 10 mg | 2 mL | 500 mcg | 5 mg/mL | 0.100 mL | 10 units | 20 |
| GHK-Cu 50 mg | 5 mL | 2 mg | 10 mg/mL | 0.200 mL | 20 units | 25 |
Questions
Does the volume of water change how much compound is in the vial?
No. It changes only the concentration. A larger volume of solvent produces a weaker solution spread across more millilitres; the total quantity of compound is unchanged.
Why bacteriostatic water rather than sterile water?
Bacteriostatic water contains 0.9% benzyl alcohol, which inhibits bacterial growth and allows a vial to be accessed more than once. Sterile water contains no preservative. Apex OZ supplies bacteriostatic water in 10 mL vials.
What is the difference between mg and mcg?
One milligram (mg) is 1,000 micrograms (mcg). Compound quantities in a vial are usually stated in milligrams, while smaller measured quantities are usually expressed in micrograms.
What do the numbers on an insulin syringe mean?
A U-100 syringe is graduated in units, where 100 units equal 1 mL. Each unit is therefore 0.01 mL. The units are a volume marking, not a quantity of compound — what a unit contains depends entirely on the concentration of the solution.
Does the size of the syringe change the answer?
No. A 0.3 mL, 0.5 mL and 1 mL insulin syringe are all the U-100 scale, so one unit is 0.01 mL on every one of them. The unit figure is identical — the smaller barrels simply spread the same volume over more of their length, which makes a small volume easier to read off.
Does this calculator tell me how much to use?
No. It converts between quantity, volume and concentration. Apex OZ supplies research compounds only, and no quantity is recommended or implied for use in humans or animals.
Bacteriostatic water
Supplied in 10 mL vials for laboratory reconstitution. View BAC Water.
Certificates of analysis
Independent laboratory analysis is published for tested batches, with purity, molecular weight and sample size stated against each result. View certificates.