Reconstitution & dose calculator

Peptide in vial (mg)Total mg printed on the vial

BAC water added (mL)Bacteriostatic water you reconstitute with

Desired dose (mg)

Syringe sizeStandard U-100 insulin syringe

Educational use only. This tool and content are for general information and do not constitute medical advice, diagnosis, or treatment. Peptides and GLP-1 medications should only be used under the supervision of a licensed healthcare provider. Always confirm dosing with your prescriber and the product label. Some peptides discussed are not approved by the FDA for human use.

Reconstitution calculator

Mix any peptide — get exact units to draw on an insulin syringe.

Retatrutide calculator

Dose the triple-agonist by units, with a titration reference.

Trending

Tirzepatide calculator

Mounjaro / Zepbound dosing in units from any vial size.

Semaglutide calculator

Ozempic / Wegovy units from compounded or vialed product.

BPC-157 calculator

Reconstitute and dose BPC-157 in micrograms.

✓

Dose tracker app

Log injections, rotate sites, never miss a dose. Private, on-device.

Free app

How peptide reconstitution works

Most research peptides and compounded GLP-1 medications ship as a freeze-dried (lyophilized) powder. Before use you reconstitute it by adding bacteriostatic (BAC) water. The amount of water you add sets the concentration, which determines how many units you draw on a U-100 insulin syringe for a given dose.

The math is simple but easy to get wrong by a decimal place:

Concentration = peptide (mg) ÷ BAC water (mL). Units to draw = (dose ÷ concentration) × 100.

Our calculator does this for you and draws the syringe so you can confirm the fill line at a glance. Change the BAC water volume to make a dose land on an easy-to-read number of units.

Frequently asked questions

Is this peptide calculator free?

Yes — every calculator and the dose tracker are completely free, with no account required. Your numbers stay on your device.

What is bacteriostatic water?

Bacteriostatic water is sterile water with 0.9% benzyl alcohol added to inhibit bacterial growth, which lets a reconstituted vial be used over multiple weeks when refrigerated. Always follow your product’s storage guidance.

How many units should I draw?

Units depend on your vial strength, how much BAC water you added, and your target dose. Enter those three values above and the calculator returns the exact units on a standard 100-unit insulin syringe.

Is this medical advice?

No. PeptideDraw is an educational tool. Dosing decisions should always be made with a licensed healthcare provider, and some peptides discussed here are not approved by the FDA for human use.

The peptide calculator that gives you exact syringe units