Reconstitution & Dosing Calculator
New to reconstitution? Read our step-by-step visual guide
1. Select Compound
2. Vial Size
3. Desired Concentration
4. Desired Dose
per injection (mg)
Educational Use Only: This calculator is provided solely for informational and educational purposes. It is not intended to provide medical advice, diagnosis, or treatment, and it does not substitute for professional judgment by a qualified healthcare provider.
How the Peptide Calculator Works
This peptide reconstitution calculator determines exact injection volumes from any vial concentration—the same math compounding pharmacies use. Enter your vial size in milligrams, the amount of bacteriostatic water you'll add, and your target dose to see the precise volume to draw.
The calculator supports GLP-1 agonists (semaglutide, tirzepatide, retatrutide), healing peptides (BPC-157, TB-500), NAD+ precursors, and any custom compound with a known concentration. Results include both insulin syringe units and milliliter measurements for standard syringes.
Frequently Asked Questions
How do I reconstitute peptides?
Add bacteriostatic water slowly down the inside wall of the vial to minimize foaming. Swirl gently—never shake vigorously. The solution should be clear and colorless. For detailed visual instructions, see our step-by-step reconstitution guide.
What is bacteriostatic water?
Bacteriostatic water is sterile water containing 0.9% benzyl alcohol, which prevents bacterial growth. It's the standard diluent for reconstituting peptides because it allows the solution to remain stable for weeks rather than hours.
How long does reconstituted peptide last?
Most peptides remain stable for 28 days when refrigerated at 2-8°C after reconstitution with bacteriostatic water. Mark your vial with the reconstitution date and discard after 28 days or if the solution becomes cloudy.
What syringe should I use for peptide injections?
Insulin syringes (typically 0.5mL or 1mL with 29-31 gauge needles) are standard for subcutaneous peptide injections. They're marked in "units" where 100 units equals 1mL. This calculator shows both unit and mL measurements.
Why does reconstitution math matter?
Accurate dosing directly affects both safety and efficacy. Under-dosing may produce no therapeutic effect; over-dosing increases side effect risk. GLP-1 agonists in particular require precise titration to minimize gastrointestinal side effects during dose escalation.