Peptide reconstitution calculator
Check concentration and U-100 syringe-unit arithmetic using a vial amount, final solution volume, and prescribed dose you already know. This web tool is separate from the PepShot iPhone app.
Enter only values confirmed with your clinician or pharmacy. For a powder reconstituted to a known final volume; not for pen clicks, blends, or an unknown liquid concentration.
Use the confirmed final volume. Do not assume water added equals final volume unless your instructions state this.
This field uses micrograms (mcg), not milligrams (mg). The calculator does not select a dose.
Enter all three positive values to check the arithmetic.
Arithmetic is not an administration instruction. Output may be rounded and may not match measurable syringe markings. It cannot verify your inputs, the product, or an appropriate injection volume. Confirm the actual instructions with your pharmacist.
How the reconstitution calculation works
- Convert the vial amount: milligrams × 1,000 = micrograms.
- Calculate concentration: micrograms in the vial ÷ final solution volume in mL = mcg/mL.
- Calculate volume: entered dose in mcg ÷ concentration in mcg/mL = mL.
- Convert to U-100 markings: volume in mL × 100 = syringe units.
U-100 means 100 marked units per mL. A syringe unit is not a fixed mass of peptide: the mass depends on the concentration. The theoretical doses-per-vial result ignores preparation loss, unused volume, and the product’s discard date.
Why do mg, mcg, mL, and units matter?
Milligrams and micrograms describe mass. Milliliters describe volume. The same marked syringe volume can contain different amounts at different concentrations. Never copy a unit count from a previous vial without checking the current instructions.
The FDA has reported dosing errors involving confusion between these measurements in compounded semaglutide. Ask the dispensing pharmacy to explain unclear instructions.
How much bacteriostatic water should I add?
This calculator cannot choose the diluent or volume. Use the exact preparation instructions supplied for your medication. Read our reconstitution recordkeeping checklist for what to confirm with the pharmacy.
Does PepShot calculate doses in the app?
No. The iPhone app is a recordkeeping tool for doses and schedules you enter. This free browser calculator is a separate arithmetic utility. Neither selects a dose or treatment plan.
Are my inputs saved or sent anywhere?
No. Calculations run in this page without sending or saving the input values. Reloading clears them. See the privacy policy.