Peptide Reconstitution Calculator

Peptide dosage calculator — enter vial mg, water mL, and desired dose to get draw volume in mL and insulin syringe units

Vial Setup

mg
1 mg50 mg
mL
0.5 mL10 mL

Dose

mg
0.05 mg5 mg
mg vs mcg: 1 mg = 1,000 mcg. Peptide doses are often prescribed in mcg (micrograms) — both units are supported here. The slider caps match common clinical ranges.

Draw volume results

Concentration
—
mg per mL
Draw volume
—
mL to inject
Syringe units
—
100-unit syringe
Doses per vial
—
at this dose
Syringe fill — 1 mL / 100 unit reference
Enter values above to see your draw
For informational use only. This calculator is a reference tool to assist with peptide reconstitution math. Always follow the guidance of a licensed medical professional for dosing, preparation, and administration. This tool does not constitute medical advice.

How to use this peptide calculator

Enter your vial size in mg (the total peptide content printed on the vial), the volume of bacteriostatic water in mL you added during reconstitution, and your desired dose in mg or mcg. The calculator instantly shows your draw volume in mL and the equivalent units on a standard 100-unit insulin syringe.

Works for all reconstituted peptides: BPC-157, TB-500, CJC-1295, Ipamorelin, PT-141, Selank, Epitalon, semaglutide, tirzepatide, Tesamorelin, DSIP, GHK-Cu, and high-dose vials like NAD+ 500 mg / 1,000 mg.

Frequently asked questions

How many units do I draw for a peptide dose? +

Units depend on your concentration. The formula is: draw volume (mL) = dose (mg) ÷ concentration (mg/mL), then multiply mL × 100 to convert to units on a 100-unit syringe. Example: 0.25 mg dose with a 2.5 mg/mL concentration = 0.1 mL = 10 units.

How much bacteriostatic water do I add to reconstitute a peptide? +

It depends on the concentration you want. Adding 1 mL to a 5 mg vial gives 5 mg/mL; adding 2 mL gives 2.5 mg/mL. More water means smaller, easier-to-measure draw volumes. Use the calculator above to find the water volume that gives you a clean, measurable draw for your dose.

What is the difference between mg and mcg for peptides? +

1 mg = 1,000 mcg. Many peptide doses are written in micrograms (mcg) — for example, a 250 mcg BPC-157 dose is the same as 0.25 mg. Switch the dose tab to mcg to enter your dose directly without converting.

How do I reconstitute a peptide vial? +

Use a fresh insulin syringe to draw bacteriostatic water, then inject it slowly along the inner wall of the peptide vial — never directly onto the powder. Do not shake; gently swirl or let it dissolve on its own. Store reconstituted peptides refrigerated and use within the timeframe recommended by your provider.

What syringe should I use to inject peptides? +

Most subcutaneous peptide injections use a 1 mL / 100-unit U-100 insulin syringe with a 29–31 gauge, 5/16" (8 mm) needle. This calculator's unit readout is calibrated to a 100-unit syringe — draw to the unit number shown in the result.