You already have the three numbers, or you are about to type them. Reconstitution math turns those quantities into a concentration and a draw volume. The calculator uses the same formulas and starts empty. It has no presets, and it does not propose an amount.
The three inputs
- Vial peptide amount, in milligrams (mg). The peptide content printed for the vial, not the weight of the glass.
- Bacteriostatic water volume, in milliliters (mL). The volume of liquid added.
- Desired amount per draw, in micrograms (mcg). An amount you type so the volume can be calculated. The site does not recommend one.
The unit bridge is 1 mg = 1,000 mcg.
Concentration
As you picture the liquid in the vial, concentration answers how many micrograms are in each milliliter after that liquid is added.
concentration (mcg/mL) = (peptide mg × 1,000) / water mL
The result assumes the labeled peptide amount is dispersed in the volume you entered, and that the volume was measured as entered. It does not correct for overfill, undissolved solid, or measurement error.
Draw volume
Draw volume answers what volume of that solution contains the amount you entered.
draw volume (mL) = desired mcg / concentration (mcg/mL)
U-100 syringe units
Some laboratory syringes marked U-100 use a scale where 100 units equal 1 mL. On that scale:
syringe units = draw volume (mL) × 100
One unit is 0.01 mL. The calculator reports units so you can compare the volume with those markings. The number is a volume conversion. It is not an instruction to administer a material.
A 1 mL U-100 syringe shows 100 units. If the calculated draw is larger than 1 mL, the unit count is larger than 100, and that volume does not fit in a single 1 mL syringe.
An arithmetic example
These figures illustrate the formulas only. They are not a suggested amount. When you run them, notice that every output is just the previous line rearranged.
| Input | Value |
|---|---|
| Vial peptide amount | 10 mg |
| Bacteriostatic water | 2 mL |
| Amount entered for the draw | 250 mcg |
- 10 mg × 1,000 = 10,000 mcg in the vial.
- 10,000 mcg / 2 mL = 5,000 mcg/mL.
- 250 mcg / 5,000 mcg/mL = 0.05 mL.
- 0.05 mL × 100 = 5 units on a U-100 scale.
Change an input and every output changes. Run your own figures in the reconstitution calculator.
Limits of the arithmetic
- The math uses the numbers you provide. It cannot check a label, a powder, or a liquid.
- Mixing, storage, and measurement technique sit outside the calculation.
- A result is not medical advice and is not for human or veterinary use.
If you are checking paperwork rather than volumes, start with how to read a certificate of analysis.