Our reconstitution calculator is one of the most-used tools on DosageTools — and for good reason. It eliminates the math involved in figuring out how many units to draw on your syringe for a specific dose after adding a specific amount of bacteriostatic water. Here is exactly how to use it.
What the Calculator Does
The reconstitution calculator answers the question: "I have X mg of peptide, I added Y mL of water, and I want Z mcg per dose — how many units do I draw on my syringe?"
It performs three calculations instantly:
- Determines your concentration (mcg per mL)
- Converts that to mcg per syringe unit
- Tells you exactly how many units to draw for your desired dose
Step-by-Step Guide
Step 1: Enter Your Peptide Amount
This is the total amount of peptide in your vial, in milligrams (mg). Common values:
- BPC-157: typically 5mg
- Ipamorelin: 2mg or 5mg
- CJC-1295: 2mg or 5mg
- Semaglutide: 3mg or 5mg
Check your vial label or supplier documentation for the exact amount.
Step 2: Enter the Amount of Bacteriostatic Water
This is how much BAC water you added (or plan to add) to the vial, in milliliters (mL). Common amounts are 1mL, 2mL, or 2.5mL. The calculator works with any amount — there is no "correct" volume, only more or less convenient concentrations.
Step 3: Enter Your Desired Dose
Enter the dose you want per injection, in micrograms (mcg). For example, 250mcg for BPC-157 or 200mcg for Ipamorelin.
Step 4: Read Your Result
The calculator displays:
- Concentration: How many mcg are in each mL of solution
- Units to draw: How many units on a U-100 insulin syringe equal your desired dose
- Doses per vial: How many total doses you can get from the vial
Example Walkthrough
Scenario: You have a 5mg BPC-157 vial, add 2mL BAC water, and want 250mcg per dose.
| Input | Value |
|---|---|
| Peptide amount | 5mg |
| Water added | 2mL |
| Desired dose | 250mcg |
Calculator output:
- Concentration: 2,500 mcg/mL (or 25 mcg per unit)
- Units to draw: 10 units
- Doses per vial: 20 doses
Tips for Best Results
- Double-check your vial amount. A 2mg vs 5mg vial gives completely different concentrations. This is the most common source of dosing errors.
- Use mL, not cc. They are the same measurement (1mL = 1cc), but our calculator uses mL for consistency.
- Bookmark the result. Once you have calculated your dosing for a specific setup, save it. You will use the same calculation for every dose from that vial.
- Recalculate for each new vial if you change your water volume or use a different peptide amount.
Common Reconstitution Volumes
| Vial Size | Water Added | Concentration | 250mcg = | 500mcg = |
|---|---|---|---|---|
| 2mg | 1mL | 2000 mcg/mL | 12.5 units | 25 units |
| 2mg | 2mL | 1000 mcg/mL | 25 units | 50 units |
| 5mg | 1mL | 5000 mcg/mL | 5 units | 10 units |
| 5mg | 2mL | 2500 mcg/mL | 10 units | 20 units |
| 5mg | 2.5mL | 2000 mcg/mL | 12.5 units | 25 units |
| 10mg | 2mL | 5000 mcg/mL | 5 units | 10 units |
What if my desired dose results in a fraction of a unit?
Insulin syringes have limited precision — typically 1-unit increments on a 1mL syringe or 0.5-unit on a 0.3mL syringe. If your calculation gives something like 12.5 units, either round to the nearest unit or adjust the amount of BAC water you add to get cleaner numbers. Our calculator shows when this happens and suggests alternative water volumes.
Does the calculator account for peptide purity?
The calculator uses the labeled amount on your vial. At 98%+ purity, the difference is negligible. If you want to calculate based on actual active content, multiply your vial amount by the purity percentage (e.g., 5mg × 0.98 = 4.9mg) and enter that as your peptide amount.