How to Use a Peptide Dosing Calculator (And Do the Math Yourself)
Converting between mg, mcg, IU, and mL trips up many researchers. This guide explains peptide dosing math step by step — and shows you how to use JA Performance's free dosing calculator.
Peptide dosing math confuses a lot of researchers — especially when units switch between milligrams (mg), micrograms (mcg), international units (IU), and millilitres (mL) depending on context. This guide walks through the calculation from first principles, so you can verify any dosing figure yourself.
Unit Conversion Basics
| Unit | Equivalent |
|---|---|
| 1 mg | 1,000 mcg |
| 1 mL of reconstituted solution | 100 IU on a standard insulin syringe |
| 1 IU on syringe | 0.01 mL |
Peptide doses are expressed in mcg (micrograms). Syringe markings are in IU (international units, where 100 IU = 1 mL). The bridge between them is the concentration of your reconstituted solution.
Step 1: Determine Concentration
Concentration (mcg/mL) = Peptide amount (mcg) ÷ Reconstitution volume (mL)
Example: You have a 5 mg (5,000 mcg) BPC-157 vial. You add 2 mL bacteriostatic water.
Concentration = 5,000 mcg ÷ 2 mL = 2,500 mcg/mL
Step 2: Calculate Volume Per Dose
Volume per dose (mL) = Desired dose (mcg) ÷ Concentration (mcg/mL)
Example continued: Research protocol calls for 250 mcg per dose.
Volume = 250 mcg ÷ 2,500 mcg/mL = 0.10 mL per dose
Step 3: Convert to Syringe Units
IU on syringe = Volume (mL) × 100
0.10 mL × 100 = 10 IU on the syringe
On a standard 1 mL insulin syringe marked 0–100 IU, you draw to the 10-unit line.
Using the JA Performance Dosing Calculator
Rather than doing this manually every time, use the free dosing calculator on this site. Input:
- ·Peptide amount in the vial (mg)
- ·Volume of bacteriostatic water added (mL)
- ·Desired dose (mcg)
The calculator outputs the exact syringe volume in both mL and IU, and shows you how many doses are in the vial. For reconstitution instructions, see the peptide reconstitution guide.
Common Reconstitution + Dose Reference
| Peptide | Vial | BW Added | Concentration | 250 mcg Dose |
|---|---|---|---|---|
| BPC-157 | 5 mg | 2 mL | 2,500 mcg/mL | 10 IU |
| BPC-157 | 10 mg | 3 mL | 3,333 mcg/mL | 7.5 IU |
| TB-500 | 5 mg | 2 mL | 2,500 mcg/mL | 10 IU |
| Retatrutide | 10 mg | 2 mL | 5,000 mcg/mL | 5 IU |
Avoiding Common Errors
- ·Forgetting to convert mg → mcg: A 5 mg vial = 5,000 mcg, not 5 mcg
- ·Mixing up total volume and dose volume: The 2 mL you added is the total — each dose is a fraction of that
- ·Syringe type mismatch: Only standard 1 mL insulin syringes have 100 IU = 1 mL; other syringe types differ
Note: All calculations here are for research reference only. JA Performance products are strictly for in vitro and laboratory research use.