Peptides come as a dry powder. You add sterile water to make them injectable. This calculator tells you exactly how much water to use — and exactly where to draw on your syringe.
What is reconstitution?
Peptides are shipped as a freeze-dried powder. Before you can inject them, you mix in bacteriostatic water — this turns the powder into a liquid. The calculator below tells you how much water to add to your vial, and exactly where to draw the plunger on a 100-unit insulin syringe for each dose.
How to reconstitute in 3 steps
Step 1
Add the water
Draw the right amount of bacteriostatic water into a syringe. Insert the needle at an angle into the vial and let the water run slowly down the inside of the glass — don't spray it directly onto the powder.
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Step 2
Swirl until clear
Gently roll the vial between your palms — never shake it. The powder should fully dissolve in 30–60 seconds. The liquid should be completely clear with no particles visible.
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Step 3
Draw your dose
Use the calculator below to get the exact units to pull on a 100-unit insulin syringe. Refrigerate the remaining vial — reconstituted peptides last 2–4 weeks when kept cold and out of light.
Quick Presets
Enter a valid vial size
Enter a valid volume
Enter a valid dose
Results
Draw This Volume
—units
Concentration
—mg/mL
Volume to Draw
—mL
Doses Per Vial
—doses
100-Unit Insulin Syringe — Target Dose Marker
0u
0102030405060708090100
Enter vial size, BAC water, and desired dose to calculate.
Reconstitution Protocol
Always use bacteriostatic water for multi-draw vials. Sterile water has no preservative — bacteria can grow once the vial is opened. BAC water contains 0.9% benzyl alcohol which prevents contamination across multiple draws.
Draw from the side of the vial. Insert the needle at an angle against the glass wall, not directly onto the powder. Let the water run down the side and pool at the bottom — this prevents foaming and peptide degradation from direct water impact.
Swirl gently — do not shake. Shaking introduces air bubbles and mechanical stress that can denature the peptide. Roll the vial between your palms or swirl slowly until the powder fully dissolves. This may take 30–60 seconds for some compounds.
Refrigerate after reconstitution. Reconstituted peptides are stable in the fridge for 2–4 weeks depending on the compound. Do not freeze after reconstitution — ice crystals damage the peptide structure. Keep away from light.
FOR RESEARCH PURPOSES ONLY. This calculator is a dosing aid for research use only and does not constitute medical advice. All calculations are based on user-entered values — verify inputs before use. Peptides are sold for research use only and are not intended for human consumption. Consult a qualified medical professional before use.
