Tools
Peptide dosing & reconstitution calculator
Turn a lyophilized peptide vial into an exact syringe draw. Enter the vial size, bacteriostatic water, and target dose to get concentration, draw volume, U-100 units, and doses per vial — validated against the formulas below. For research and educational reference only.
At 5,000 micrograms per millilitre, a 500 microgram dose is 0.1 millilitres, or 10 units on a U-100 syringe, giving 20 doses per vial.
The formulas
- Concentration
- = (vial mg × 1000) ÷ BAC water mL → mcg/mL
- Draw volume
- = target dose mcg ÷ concentration → mL
- Syringe units
- = draw volume mL × 100 → U-100
- Doses per vial
- = (vial mg × 1000) ÷ dose mcg → doses
Worked example
A 10 mg vial + 2 mL water = 5,000 mcg/mL. A 500 mcg dose = 0.1 mL = 10 units, giving 20 doses per vial.
Reading the warnings
- Under 5 units — the draw is hard to measure accurately; use less water for a larger draw.
- Over syringe size — the draw won't fit; use more water or split the dose.
Peptide dosing calculator — FAQ
How do I calculate a peptide dose?
First find the concentration: multiply the vial size in milligrams by 1000, then divide by the millilitres of bacteriostatic water you added — that gives mcg/mL. Then divide your target dose in micrograms by that concentration to get the draw volume in millilitres, and multiply the volume by 100 to get the units on a U-100 insulin syringe. The calculator above does all of this live as you type.
How much bacteriostatic water should I add to a peptide vial?
Any volume works — the water only changes the concentration, not the total amount of peptide in the vial. More water makes each dose a larger, easier-to-read draw at a lower concentration; less water concentrates it into a smaller draw. The calculator flags draws under 5 units (hard to measure accurately) and draws larger than your chosen syringe, so you can adjust the water until the dose lands in a comfortable range.
How many units is my peptide dose on an insulin syringe?
Insulin syringes are graduated U-100, where 100 units equals 1 mL. So units = draw volume in mL × 100. For example, a 0.1 mL draw is 10 units. Enter your vial size, water, and dose above to see the exact unit mark to draw to.
How many doses are in a peptide vial?
Divide the total micrograms in the vial (vial mg × 1000) by your per-dose micrograms, then round down. A 10 mg vial at a 500 mcg dose gives 20 doses. The calculator reports this as 'doses per vial.'
Does this calculator work for any peptide?
Yes. Reconstitution math is identical for every lyophilized peptide — only your vial size, water volume, and target dose matter — so the same calculator works for BPC-157, semaglutide, tirzepatide, ipamorelin, and the rest. All figures are for research and educational reference only.
For educational and research reference only. Not intended for human consumption, not medical advice. Compounds discussed are sold and used for laboratory research purposes only.