Peptide Reconstitution & Dose Calculator
Enter your vial, BAC water and target dose — get exact syringe units in seconds. Then track every shot in the Peptide Me app.
How it works
How peptide reconstitution & dosing works
Most research peptides — and many compounded GLP-1 medications — arrive as a lyophilized (freeze-dried) powder that has to be turned back into a liquid before you can draw a dose. That is what reconstitution means: you add a measured volume of bacteriostatic water (sterile water with a small amount of benzyl alcohol as a preservative) to the vial, swirl gently until it dissolves, and end up with a solution at a known concentration. The calculator above does the math that turns that concentration into an exact number of insulin-syringe units.
Concentration: the number everything depends on
Concentration is simply how much peptide sits in each millilitre of solution. Reconstitute a 10 mg vial with 2 mL of bacteriostatic water and you have 10,000 mcg ÷ 2 mL = 5,000 mcg per mL. Add more water and each dose becomes easier to measure (more units on the syringe); add less and the injection volume gets smaller. There is no single “correct” amount of water — the reconstitution calculator's Easier to measure vs Smaller injection toggle just suggests a sensible volume either way.
Units, mL and mcg: converting between them
This is where most dosing errors happen, because peptides are usually dosed in micrograms (mcg) while a U-100 insulin syringe is marked in units, where 100 units = 1 mL. To find your units, divide your target dose by the concentration to get the volume in mL, then multiply by 100. Using the example above, a 250 mcg dose ÷ 5,000 mcg/mL = 0.05 mL = 5 units. Doing that by hand, on a different vial size, late at night, is exactly where a decimal-point slip can 10× a dose — which is the whole reason to use a calculator instead of mental math. The half-life calculator then shows how those doses build up over a cycle.
Storing your vial after mixing
Once reconstituted, a peptide is a protein dissolved in water and begins degrading — heat, light and shaking all speed it up. General practice is to refrigerate the vial at 2–8°C, keep it out of light, avoid freezing, and discard it if the solution turns cloudy. For the step-by-step injection technique that follows reconstitution, see how to reconstitute & inject peptides, and read are peptides safe? for the honest evidence and legal picture before starting anything.
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