Peptide Dose Calculator
Convert any peptide dose to exact syringe units in one step. Enter your vial size, how much bacteriostatic water you added, and your target dose.
Track every dose automatically
PepStackr remembers your vial setup, logs every injection in one tap, and shows you exactly how many doses you have left. Free to start.
Create Free AccountHow the Math Works
Once a peptide vial is reconstituted, it becomes a solution with a known concentration. That concentration — how many micrograms (mcg) of peptide sit in every unit on your insulin syringe — is the only thing you need to know to calculate any dose.
The Two-Step Calculation
Step 1 — Concentration:
mcg per unit = (peptide mg × 1000) ÷ (BAC water mL × 100)
Step 2 — Units to draw:
units = desired dose in mcg ÷ mcg per unit
A Worked Example
You have a 5mg BPC-157 vial and you added 2mL of BAC water. Your target dose is 250mcg.
- Concentration: (5 × 1000) ÷ (2 × 100) = 25 mcg per unit
- Units to draw: 250 ÷ 25 = 10 units on a standard insulin syringe
- Doses per vial: 5000mcg ÷ 250mcg = 20 doses
Syringe Sizes
Standard U-100 insulin syringes have 100 units per 1mL. For small doses (under 30 units), a 0.3mL (30-unit) syringe gives finer gradations — each mark is 0.5 units rather than 1 unit. For GLP-1 weekly doses in the 40–80 unit range, a 1mL (100-unit) syringe is more appropriate.