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Free reconstitution calculator + regimen builder. No signup. Runs in your browser.
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Peptide Reconstitution Calculator

Use this free reconstitution calculator to turn the mixing math into a syringe mark. Enter your vial size (mg), the bacteriostatic water (mL) you added, and your dose, and it shows the units to draw on a U-100 insulin syringe, the concentration (mg/mL), and how many doses the vial holds. It does the arithmetic only — it never recommends a dose.

How the math works

Concentration = vial mg × 1000 ÷ water mL (in mcg per mL). Units to draw = dose ÷ concentration × 100 on a U-100 syringe, where 100 units = 1 mL. And 1 mg = 1000 mcg — mixing those up is the most common serious error, so the calculator shows both.

A worked example

Illustrative only, not a recommendation. A 10 mg vial with 2 mL of bacteriostatic water is 5 mg/mL. For a 0.25 mg dose: 0.25 ÷ 5 = 0.05 mL = 5 units. Add more water and the same dose becomes more units — which is why you always use your own vial’s numbers.

Mixing-math, not a dosage tool

This calculator prepares the solution math; it does not choose a dose or give medical advice. Your dose is a decision for you and your prescriber. Research peptides are not for human consumption in most jurisdictions — only FDA-approved drugs and prescriptions from licensed 503A/503B compounders are permitted where applicable.

Learn the details

Common questions

What does a reconstitution calculator do?

It turns the mixing math into a syringe mark. You enter the vial size (mg), the bacteriostatic water you added (mL), and your dose, and it shows the units to draw on a U-100 insulin syringe, the concentration (mg/mL), and how many doses the vial holds. It does the arithmetic only — it never chooses a dose.

Is this a dosage calculator?

No. It is mixing-math, not a dosage calculator. Your dose is a decision you make with your prescriber; this tool just converts that dose into a syringe mark at your vial’s concentration.

How is the concentration worked out?

Concentration = vial mg × 1000, divided by the water in mL, expressed in mcg per mL (or mg/mL). The units to draw are then the dose divided by the concentration, times 100 on a U-100 syringe.

Is the calculator free and private?

Yes. It is free, needs no signup, and runs entirely in your browser — the numbers you enter are not sent anywhere.

What water do I use to reconstitute?

Bacteriostatic water is commonly used for multi-dose vials; some compounds specify a different diluent. The right diluent for your product is on its label or from your pharmacist.

Diluent quick reference: Bac water (default, ~28d shelf, 0.9% benzyl alcohol) | Sterile saline (intranasal, single-dose) | Bacteriostatic saline (isotonic + preservative — good for IM multi-dose) | 0.6% acetic acid (GHK-Cu, AOD-9604, IGF-1, GHRP-2/6, MGF). Each entry above shows the recommended diluent.

Privacy: This calculator runs entirely in your browser — the numbers you enter are not sent anywhere.
Disclaimer: Information tool only - not medical advice. Discuss any peptide protocol with your physician. Research peptides are not for human consumption in most jurisdictions; only FDA-approved drugs and prescriptions from licensed 503A / 503B compounders are permitted where applicable.

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