Free tool
Peptide Calculator: Reconstitution & Dose Calculator
Enter the peptide amount in your vial, the bacteriostatic water you add and the dose you want. The peptide calculator instantly shows the concentration, how many mL to draw and the units on a U-100 insulin syringe.
Your vial
Draw to
5 units
0.05 mL on a U-100 syringe
0.25 mg per dose
Syringe size · 1 mL (100 u)
- Concentration
- 5 mg/mL
- 5,000 mcg / mL
- Volume per dose
- 0.05 mL
- 5 units
- Doses per vial
- 40
- 0.25 mg each
- Vial lasts
- 40 days
- ≈ 5.7 weeks
Figures are calculated from the values you enter and are provided for laboratory reference only. Kuulpeps does not supply dosing protocols or medical guidance.
Research use only. Not for human consumption.
How the peptide reconstitution calculator works
- Concentration = peptide mg ÷ water mL. A 10 mg vial with 2 mL of bacteriostatic water gives 5 mg/mL (5,000 mcg/mL).
- Volume to draw = dose (mcg) ÷ concentration (mcg/mL).
- Units on a U-100 insulin syringe = volume in mL × 100, because 1 mL = 100 units.
- Doses per vial = total mcg in the vial ÷ dose in mcg.
Worked example
Retatrutide 10 mg + 2 mL bacteriostatic water = 5,000 mcg/mL. For a 500 mcg dose, draw 0.1 mL — that is 10 units on a U-100 syringe, and the vial holds 20 doses.
Peptide calculator FAQ
How much bacteriostatic water should I add to a peptide vial?
Common choices are 1, 2 or 3 mL. More water lowers the concentration, which makes small doses easier to measure accurately on the syringe.
How many units is 250 mcg?
It depends on the concentration. With 5 mg in 2 mL (2,500 mcg/mL), 250 mcg is 0.1 mL, or 10 units on a U-100 syringe. Use the calculator above for your own vial.
What is the difference between mg and mcg?
1 mg equals 1,000 mcg. Vials are usually labelled in mg, while doses are usually written in mcg.
Does this work for every peptide?
Yes. The maths is the same for BPC-157, TB-500, GHK-Cu, retatrutide, blends and any other lyophilised peptide.