Peptide Reconstitution
Calculator
Enter your vial strength, the bacteriostatic water you're adding, and your target dose. Get the exact draw on a standard insulin syringe — plus concentration and doses per vial.
Your vial
Draw to
= 0.10 mL on the syringe
How this works
Methodology reviewed July 2026Reconstitution is pure arithmetic. Dividing the vial strength (mg) by the bacteriostatic water you add (mL) gives the concentration in mg/mL. Your target dose is converted to milligrams and divided by that concentration to get the volume to draw in mL, which — on a standard U-100 insulin syringe where 1 mL is 100 units — is multiplied by 100 to read straight off the barrel. Because the peptide mass in the vial is fixed, the number of doses depends only on vial strength and dose size, not on how much water you add; water changes the concentration and the draw volume, never the dose count.
concentration [mg/mL] = vial_strength_mg / bac_water_mL
dose_mg = dose_mcg / 1000 (if entered in mcg)
draw_volume_mL = dose_mg / concentration
insulin_units (U-100) = draw_volume_mL × 100
mcg_per_unit = concentration × 1000 / 100
doses_per_vial = (vial_strength_mg × 1000) / dose_mcg
Vial strength (mg) · Bacteriostatic water (mL) · Target dose (mcg or mg) · Syringe size
Draw volume (mL) · Insulin-syringe units · Concentration (mg/mL) · Micrograms per unit · Doses per vial
- Doses are measured on a standard U-100 insulin syringe, where 100 units equal exactly 1 mL.
- The peptide fully dissolves and distributes evenly, so concentration is uniform across every draw.
- Adding more or less water changes the concentration and draw volume but never the total peptide mass, so doses per vial are independent of water volume.
- The vial is labeled accurately — the calculation is only as correct as the milligram figure you enter.
- This is unit arithmetic only; it does not judge whether a dose is safe, effective, or appropriate for any purpose.
- It cannot account for peptide lost to filters, adsorption to the vial, dead space in the needle, or incomplete dissolution.
- Very small draws (a fraction of a unit) are hard to measure accurately on any syringe and magnify any labeling or handling error.
- Watch the units carefully — micrograms (mcg), milligrams (mg), millilitres (mL), and insulin units are four different things, and the tool's mcg/mg toggle exists precisely because confusing them is the most common and most dangerous dosing error.
- The number returned is the arithmetic result of the figures you enter, not a recommended or safe dose for anyone; the tool never endorses a dose.
- Impossible inputs are rejected — all three fields must be positive numbers — and a draw that exceeds the selected syringe's capacity triggers a warning to use a larger syringe or split the draw rather than silently overfilling.
- Many research peptides are not approved for human use; the tool computes math only and is not a recommendation to obtain, prepare, or use any peptide.
This calculator is for educational purposes only and is not medical advice, diagnosis, or treatment. Results are estimates based on published formulas and population averages — your individual values may differ. Nothing here is calculated on a server: everything runs in your browser and no data is stored or sent anywhere. Always consult a qualified clinician before making health, medication, or training decisions.