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Free research tool

Peptide Reconstitution Calculator

Convert vial size, bacteriostatic water volume and target dose into the exact insulin-syringe units to draw — with a live syringe preview. Everything runs in your browser.

Reconstitution calculator

Enter your vial, diluent and target dose — the syringe updates live.

mg
ml
mcg

Toggling converts the value between micrograms and milligrams.

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U-100 Insulin Syringe (100 units)

20.0 units

Dosing instructions

For a dose of 500 mcg, draw the syringe to 20 units.

Concentration
2.5 mg/ml
Volume to draw
0.2 ml
Syringe units
20 / 100
Syringe type
U-100 insulin

How the Math Works

The calculator applies three simple conversions — the same ones you can verify by hand:

1. Concentration

Peptide quantity (mg) ÷ bacteriostatic water (ml) = concentration in mg/ml. A 5 mg vial with 2 ml of water is 2.5 mg/ml.

2. Volume per dose

Desired dose (mg) ÷ concentration (mg/ml) = volume to draw in ml. A 500 mcg (0.5 mg) dose at 2.5 mg/ml is 0.2 ml.

3. Syringe units

Volume (ml) × 100 = units on a U-100 insulin syringe. 0.2 ml equals the 20-unit mark.

Understanding the Inputs

Peptide quantity
The total amount of lyophilized peptide in your vial, in milligrams (mg) — printed on the vial label.
Bacteriostatic water
The volume of diluent you add to reconstitute the peptide, in milliliters (ml). This sets the concentration.
Desired dose
The amount of peptide per administration, in micrograms (mcg) or milligrams (mg) — the toggle converts between the two.
Syringe volume
The size of your U-100 insulin syringe (0.3, 0.5 or 1.0 ml), which sets the maximum draw and the tick spacing.

Frequently Asked Questions

How many units is 1 ml on an insulin syringe?
On a standard U-100 insulin syringe, 1 ml equals 100 units, so each unit mark represents 0.01 ml. Drawing 0.2 ml therefore means drawing to the 20-unit mark.
How much bacteriostatic water should I add to a peptide vial?
Any practical volume works — the water only changes the concentration, not the total amount of peptide in the vial. More water means more units per dose, which makes small doses easier to measure accurately on the syringe. Common volumes are 1, 2 or 3 ml.
What is the difference between mcg and mg?
1 milligram (mg) equals 1,000 micrograms (mcg). Peptide vials are usually labelled in mg while research doses are often described in mcg, so the calculator lets you enter the dose in either unit and converts between them.
Does the calculator store or send my inputs anywhere?
No. All calculations run locally in your browser — nothing you type is stored or transmitted.