Peptide Reconstitution Calculator
Enter the mg of peptide in your vial, the mL of bacteriostatic water you add, and your desired dose. The calculator returns the concentration (mg/mL), volume to draw (mL), and the exact units to draw on a U-100 insulin syringe. Educational math only — never a dose recommendation.
Reconstitution Calculator
Check the decimal. A misplaced decimal point here is a 10× dosing error. Re-read every number, and confirm your dose with a licensed clinician before you draw.
Educational only — not a dosing recommendation. This tool does the measurement math; it does not tell you what to take. On a U-100 insulin syringe, 100 units = 1 mL.
How the reconstitution math works
Reconstitution math is just four short formulas. Once you know the concentration of your solution, every other number — volume, units, and doses per vial — falls out of it.
What is the concentration after mixing?
Concentration is the peptide mass divided by the water volume. It is the single number the rest of the math depends on.
concentration (mg/mL) = peptide (mg) ÷ BAC water (mL)How many mcg are in one insulin unit?
A U-100 insulin syringe has 100 units per mL, so each unit holds 1/100 mL. Multiplying the concentration by 10 converts mg/mL into micrograms per unit.
mcg per unit = concentration (mg/mL) × 10What volume do I draw for a dose?
Convert the dose to milligrams (divide mcg by 1000), then divide by the concentration to get the volume in milliliters.
volume to draw (mL) = (dose in mcg ÷ 1000) ÷ concentration (mg/mL)How many units is that on the syringe?
Because 100 units equal 1 mL on a U-100 syringe, multiply the volume in mL by 100 to get the unit mark to fill to.
units to draw = volume to draw (mL) × 100How many doses does a vial hold?
Divide the total peptide (converted to micrograms) by the dose in micrograms.
doses per vial = (peptide in mg × 1000) ÷ dose in mcgA fully worked example
Suppose a vial contains 5 mg of peptide and you add 2 mL of bacteriostatic water, with a desired dose of 250 mcg. Here is each step:
- Concentration: 5 mg ÷ 2 mL = 2.5 mg/mL.
- mcg per unit: 2.5 × 10 = 25 mcg per unit.
- Volume to draw: (250 ÷ 1000) ÷ 2.5 = 0.25 ÷ 2.5 = 0.10 mL.
- Units to draw: 0.10 mL × 100 = 10 units on a U-100 syringe.
- Doses per vial: (5 × 1000) ÷ 250 = 5000 ÷ 250 = 20 doses.
So at this concentration, a 250 mcg dose is the 10-unit mark, and the vial holds 20 such doses. Change any input above and the numbers recompute instantly.
Reference table: units per dose at 2.5 mg/mL
For a vial reconstituted to 2.5 mg/mL (5 mg in 2 mL), here is how common doses map to syringe units. Use the calculator for your own concentration.
| Dose | Volume to draw | Units (U-100) |
|---|---|---|
| 100 mcg | 0.04 mL | 4 units |
| 250 mcg | 0.10 mL | 10 units |
| 500 mcg | 0.20 mL | 20 units |
| 1 mg (1000 mcg) | 0.40 mL | 40 units |
BAC water & mixing math guide
The full walkthrough behind these formulas — what bacteriostatic water is, how to choose a dilution, and the most common mixing mistakes.
Read the guideThese units go in a U-100 insulin syringe
The units above are read off a standard U-100 insulin syringe. Our injection guide walks through drawing up, clearing air bubbles, and a clean, safe subcutaneous technique.
Read injection 101Got your numbers?
Double-check every figure, never exceed what a licensed clinician advised, and keep learning — the weekly Letter and the community are free.
Frequently asked questions
- How do you calculate peptide reconstitution?
- Divide the peptide mass by the water volume to get concentration: concentration (mg/mL) = peptide (mg) ÷ BAC water (mL). To find the volume for a dose, divide the dose (converted to mg) by that concentration. Multiply the volume in mL by 100 to get insulin units on a U-100 syringe.
- How many units is a peptide dose on an insulin syringe?
- Units = volume to draw (mL) × 100, because a U-100 insulin syringe holds 100 units per 1 mL. For example, 0.10 mL is 10 units. The calculator above converts any dose-and-concentration combination into units for you.
- How much bacteriostatic water should I add to a peptide vial?
- There is no single correct amount — more water makes the solution more dilute (easier to measure small doses), less water makes it more concentrated. The volume you add only changes the math, not the total peptide. Use the calculator to see how a given water volume affects units per dose.
- What does mcg per insulin unit mean?
- It is how many micrograms of peptide sit in each 1-unit mark on a U-100 syringe at your chosen concentration: mcg per unit = concentration (mg/mL) × 10. It lets you read a dose straight off the syringe without re-doing the math each time.
- Is this calculator medical advice?
- No. It is a measurement tool that performs arithmetic on numbers you enter. It does not recommend a dose, a peptide, or a protocol, and it is not a substitute for a licensed healthcare provider. WikiPeps is educational and does not sell or source peptides.