How to Reconstitute Peptides: Calculator, Formula & Insulin Unit Charts
The reconstitution formula, mg-to-insulin-unit reference tables, how to pick a diluent volume, and the five most common mixing mistakes.
By PX1 Research Team · August 4, 2026
The only formula you need
$$\text{Volume (mL)} = \frac{\text{Target amount}}{\text{Concentration (mg/mL)}}$$
And concentration is simply vial strength divided by diluent added. On a U-100 insulin syringe, 1 mL = 100 units, so units = mL × 100.
Worked example
A 10 mg vial reconstituted with 2 mL is 5 mg/mL. Targeting 2 mg: 2 ÷ 5 = 0.4 mL = 40 units.
Quick-reference: units per 1 mg by concentration
| Concentration | Units per 1 mg |
|---|---|
| 1 mg/mL | 100 |
| 2 mg/mL | 50 |
| 2.5 mg/mL | 40 |
| 5 mg/mL | 20 |
| 10 mg/mL | 10 |
Choosing a diluent volume
More diluent means larger, easier-to-measure volumes but a lower concentration and a bulkier vial. Less diluent means precise small volumes that are harder to read on a syringe. For microgram-range compounds (BPC-157, KPV, semax) prefer a dilute prep so the mark falls in a readable part of the barrel. For milligram-range metabolic compounds, 5–10 mg/mL keeps volumes under 1 mL.
Common mistakes
- Shaking the vial. Swirl only; foam indicates shear.
- Injecting diluent onto the cake. Aim at the glass wall.
- Assuming volume changes potency. It does not — it changes concentration only.
- Reading a U-40 syringe as U-100. Check the barrel; the two scales differ by 2.5×.
- Skipping the date label. Bacteriostatic preparations expire ~28 days from first puncture.
Step-by-step
- Bring the lyophilized vial to room temperature.
- Wipe both stoppers with 70% isopropyl alcohol.
- Draw your calculated diluent volume.
- Inject slowly down the inside vial wall.
- Swirl until fully dissolved — do not shake.
- Label with concentration and date, refrigerate at 2–8 °C.
Run any combination through the peptide calculator.
All figures below are reported from published laboratory literature and are provided for informational and laboratory-research context only. PX1 Research supplies compounds for laboratory and research use only — not for human or veterinary use.